Re: [PATCH v4] serial: make uart_console_write->putchar()'s character an unsigned char

[Paul Cercueil <paul@xxxxxxxxxxxxxxx>]

Hi Jiri,

Le jeu., mars 3 2022 at 09:08:31 +0100, Jiri Slaby <jslaby@xxxxxxx> a 
écrit :
> Currently, uart_console_write->putchar's second parameter (the
> character) is of type int. It makes little sense, provided 
> uart_console_write()
> accepts the input string as "const char *s" and passes its content -- 
> the
> characters -- to putchar(). So switch the character's type to unsigned
> char.
>
> We don't use char as that is signed on some platforms. That would 
> cause
> troubles for drivers which (implicitly) cast the char to u16 when
> writing to the device. Sign extension would happen in that case and 
> the
> value written would be completely different to the provided char. DZ 
> is
> an example of such a driver -- on MIPS, it uses u16 for dz_out in
> dz_console_putchar().
>
> Note we do the char -> uchar conversion implicitly in
> uart_console_write(). Provided we do not change size of the data type,
> sign extension does not happen there, so the problem is void.
>
> This makes the types consistent and unified with the rest of the uart
> layer, which uses unsigned char in most places already. One exception 
> is
> xmit_buf, but that is going to be converted later.
>
> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
> Acked-by: Richard Genoud <richard.genoud@xxxxxxxxx> [atmel_serial]
> Acked-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> Cc: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> Cc: Tobias Klauser <tklauser@xxxxxxxxxx>
> Cc: Russell King <linux@xxxxxxxxxxxxxxx>
> Cc: Vineet Gupta <vgupta@xxxxxxxxxx>
> Cc: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
> Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> Cc: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
> Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
> Cc: bcm-kernel-feedback-list@xxxxxxxxxxxx
> Cc: Alexander Shiyan <shc_work@xxxxxxx>
> Cc: Baruch Siach <baruch@xxxxxxxxxx>
> Cc: "Maciej W. Rozycki" <macro@xxxxxxxxxxx>
> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
> Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
> Cc: Fabio Estevam <festevam@xxxxxxxxx>
> Cc: NXP Linux Team <linux-imx@xxxxxxx>
> Cc: Karol Gugala <kgugala@xxxxxxxxxxxx>
> Cc: Mateusz Holenko <mholenko@xxxxxxxxxxxx>
> Cc: Vladimir Zapolskiy <vz@xxxxxxxxx>
> Cc: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> Cc: Kevin Hilman <khilman@xxxxxxxxxxxx>
> Cc: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> Cc: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> Cc: Taichi Sugaya <sugaya.taichi@xxxxxxxxxxxxx>
> Cc: Takao Orito <orito.takao@xxxxxxxxxxxxx>
> Cc: Liviu Dudau <liviu.dudau@xxxxxxx>
> Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: "Andreas Färber" <afaerber@xxxxxxx>
> Cc: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Andy Gross <agross@xxxxxxxxxx>
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx>
> Cc: Orson Zhai <orsonzhai@xxxxxxxxx>
> Cc: Baolin Wang <baolin.wang7@xxxxxxxxx>
> Cc: Chunyan Zhang <zhang.lyra@xxxxxxxxx>
> Cc: Patrice Chotard <patrice.chotard@xxxxxxxxxxx>
> Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
> Cc: Alexandre Torgue <alexandre.torgue@xxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Peter Korsgaard <peter@xxxxxxxxxxxxx>
> Cc: Michal Simek <michal.simek@xxxxxxxxxx>
> ---
> [v2] make it unsigned
> [v3] fix also sunsab
> [v4] fix also sunplus (added quite recently)
>
>  drivers/tty/goldfish.c                     | 2 +-
>  drivers/tty/hvc/hvc_dcc.c                  | 2 +-
>  drivers/tty/serial/21285.c                 | 2 +-
>  drivers/tty/serial/8250/8250_early.c       | 2 +-
>  drivers/tty/serial/8250/8250_ingenic.c     | 2 +-

For Ingenic:

Acked-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>

Cheers,
-Paul

>  drivers/tty/serial/8250/8250_port.c        | 2 +-
>  drivers/tty/serial/altera_jtaguart.c       | 4 ++--
>  drivers/tty/serial/altera_uart.c           | 2 +-
>  drivers/tty/serial/amba-pl010.c            | 2 +-
>  drivers/tty/serial/amba-pl011.c            | 6 +++---
>  drivers/tty/serial/apbuart.c               | 2 +-
>  drivers/tty/serial/ar933x_uart.c           | 2 +-
>  drivers/tty/serial/arc_uart.c              | 2 +-
>  drivers/tty/serial/atmel_serial.c          | 2 +-
>  drivers/tty/serial/bcm63xx_uart.c          | 2 +-
>  drivers/tty/serial/clps711x.c              | 2 +-
>  drivers/tty/serial/digicolor-usart.c       | 2 +-
>  drivers/tty/serial/dz.c                    | 2 +-
>  drivers/tty/serial/earlycon-arm-semihost.c | 2 +-
>  drivers/tty/serial/earlycon-riscv-sbi.c    | 2 +-
>  drivers/tty/serial/fsl_linflexuart.c       | 4 ++--
>  drivers/tty/serial/fsl_lpuart.c            | 4 ++--
>  drivers/tty/serial/imx.c                   | 2 +-
>  drivers/tty/serial/imx_earlycon.c          | 2 +-
>  drivers/tty/serial/ip22zilog.c             | 2 +-
>  drivers/tty/serial/lantiq.c                | 2 +-
>  drivers/tty/serial/liteuart.c              | 2 +-
>  drivers/tty/serial/lpc32xx_hs.c            | 2 +-
>  drivers/tty/serial/meson_uart.c            | 2 +-
>  drivers/tty/serial/milbeaut_usio.c         | 2 +-
>  drivers/tty/serial/mps2-uart.c             | 4 ++--
>  drivers/tty/serial/mvebu-uart.c            | 4 ++--
>  drivers/tty/serial/mxs-auart.c             | 2 +-
>  drivers/tty/serial/omap-serial.c           | 4 ++--
>  drivers/tty/serial/owl-uart.c              | 2 +-
>  drivers/tty/serial/pch_uart.c              | 2 +-
>  drivers/tty/serial/pic32_uart.c            | 2 +-
>  drivers/tty/serial/pmac_zilog.c            | 2 +-
>  drivers/tty/serial/pxa.c                   | 2 +-
>  drivers/tty/serial/qcom_geni_serial.c      | 2 +-
>  drivers/tty/serial/rda-uart.c              | 2 +-
>  drivers/tty/serial/sa1100.c                | 2 +-
>  drivers/tty/serial/samsung_tty.c           | 4 ++--
>  drivers/tty/serial/sb1250-duart.c          | 2 +-
>  drivers/tty/serial/sccnxp.c                | 2 +-
>  drivers/tty/serial/serial_core.c           | 2 +-
>  drivers/tty/serial/serial_txx9.c           | 2 +-
>  drivers/tty/serial/sh-sci.c                | 2 +-
>  drivers/tty/serial/sifive.c                | 4 ++--
>  drivers/tty/serial/sprd_serial.c           | 4 ++--
>  drivers/tty/serial/st-asc.c                | 2 +-
>  drivers/tty/serial/stm32-usart.c           | 2 +-
>  drivers/tty/serial/sunplus-uart.c          | 5 +++--
>  drivers/tty/serial/sunsab.c                | 2 +-
>  drivers/tty/serial/sunsu.c                 | 2 +-
>  drivers/tty/serial/sunzilog.c              | 4 ++--
>  drivers/tty/serial/uartlite.c              | 4 ++--
>  drivers/tty/serial/vr41xx_siu.c            | 2 +-
>  drivers/tty/serial/vt8500_serial.c         | 2 +-
>  drivers/tty/serial/xilinx_uartps.c         | 2 +-
>  drivers/tty/serial/zs.c                    | 2 +-
>  include/linux/serial_core.h                | 2 +-
>  62 files changed, 77 insertions(+), 76 deletions(-)
>
> diff --git a/drivers/tty/goldfish.c b/drivers/tty/goldfish.c
> index 5ed19a9857ad..ad13532e92fe 100644
> --- a/drivers/tty/goldfish.c
> +++ b/drivers/tty/goldfish.c
> @@ -434,7 +434,7 @@ static int goldfish_tty_remove(struct 
> platform_device *pdev)
>  }
>
>  #ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE
> -static void gf_early_console_putchar(struct uart_port *port, int ch)
> +static void gf_early_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	__raw_writel(ch, port->membase);
>  }
> diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c
> index 8e0edb7d93fd..bd61f9372d83 100644
> --- a/drivers/tty/hvc/hvc_dcc.c
> +++ b/drivers/tty/hvc/hvc_dcc.c
> @@ -15,7 +15,7 @@
>  #define DCC_STATUS_RX		(1 << 30)
>  #define DCC_STATUS_TX		(1 << 29)
>
> -static void dcc_uart_console_putchar(struct uart_port *port, int ch)
> +static void dcc_uart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	while (__dcc_getstatus() & DCC_STATUS_TX)
>  		cpu_relax();
> diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c
> index 09baef4ccc39..7520cc02fd4d 100644
> --- a/drivers/tty/serial/21285.c
> +++ b/drivers/tty/serial/21285.c
> @@ -403,7 +403,7 @@ static void serial21285_setup_ports(void)
>  }
>
>  #ifdef CONFIG_SERIAL_21285_CONSOLE
> -static void serial21285_console_putchar(struct uart_port *port, int 
> ch)
> +static void serial21285_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	while (*CSR_UARTFLG & 0x20)
>  		barrier();
> diff --git a/drivers/tty/serial/8250/8250_early.c 
> b/drivers/tty/serial/8250/8250_early.c
> index c171ce6db691..e52585064565 100644
> --- a/drivers/tty/serial/8250/8250_early.c
> +++ b/drivers/tty/serial/8250/8250_early.c
> @@ -86,7 +86,7 @@ static void serial8250_early_out(struct uart_port 
> *port, int offset, int value)
>
>  #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
>
> -static void serial_putc(struct uart_port *port, int c)
> +static void serial_putc(struct uart_port *port, unsigned char c)
>  {
>  	unsigned int status;
>
> diff --git a/drivers/tty/serial/8250/8250_ingenic.c 
> b/drivers/tty/serial/8250/8250_ingenic.c
> index 65402d05eff9..cff91aa03f29 100644
> --- a/drivers/tty/serial/8250/8250_ingenic.c
> +++ b/drivers/tty/serial/8250/8250_ingenic.c
> @@ -52,7 +52,7 @@ static void early_out(struct uart_port *port, int 
> offset, uint8_t value)
>  	writel(value, port->membase + (offset << 2));
>  }
>
> -static void ingenic_early_console_putc(struct uart_port *port, int c)
> +static void ingenic_early_console_putc(struct uart_port *port, 
> unsigned char c)
>  {
>  	uint8_t lsr;
>
> diff --git a/drivers/tty/serial/8250/8250_port.c 
> b/drivers/tty/serial/8250/8250_port.c
> index d30a6c1c4c20..c9c5bbdca80a 100644
> --- a/drivers/tty/serial/8250/8250_port.c
> +++ b/drivers/tty/serial/8250/8250_port.c
> @@ -3319,7 +3319,7 @@ EXPORT_SYMBOL_GPL(serial8250_set_defaults);
>
>  #ifdef CONFIG_SERIAL_8250_CONSOLE
>
> -static void serial8250_console_putchar(struct uart_port *port, int 
> ch)
> +static void serial8250_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct uart_8250_port *up = up_to_u8250p(port);
>
> diff --git a/drivers/tty/serial/altera_jtaguart.c 
> b/drivers/tty/serial/altera_jtaguart.c
> index 37bffe406b18..1c16345d0a1f 100644
> --- a/drivers/tty/serial/altera_jtaguart.c
> +++ b/drivers/tty/serial/altera_jtaguart.c
> @@ -298,7 +298,7 @@ static struct altera_jtaguart 
> altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];
>  #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)
>
>  #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
> -static void altera_jtaguart_console_putc(struct uart_port *port, int 
> c)
> +static void altera_jtaguart_console_putc(struct uart_port *port, 
> unsigned char c)
>  {
>  	unsigned long status;
>  	unsigned long flags;
> @@ -318,7 +318,7 @@ static void altera_jtaguart_console_putc(struct 
> uart_port *port, int c)
>  	spin_unlock_irqrestore(&port->lock, flags);
>  }
>  #else
> -static void altera_jtaguart_console_putc(struct uart_port *port, int 
> c)
> +static void altera_jtaguart_console_putc(struct uart_port *port, 
> unsigned char c)
>  {
>  	unsigned long flags;
>
> diff --git a/drivers/tty/serial/altera_uart.c 
> b/drivers/tty/serial/altera_uart.c
> index 64a352b40197..8b749ed557c6 100644
> --- a/drivers/tty/serial/altera_uart.c
> +++ b/drivers/tty/serial/altera_uart.c
> @@ -438,7 +438,7 @@ static struct altera_uart 
> altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];
>
>  #if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
>
> -static void altera_uart_console_putc(struct uart_port *port, int c)
> +static void altera_uart_console_putc(struct uart_port *port, 
> unsigned char c)
>  {
>  	while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
>  		 ALTERA_UART_STATUS_TRDY_MSK))
> diff --git a/drivers/tty/serial/amba-pl010.c 
> b/drivers/tty/serial/amba-pl010.c
> index b73375214ac3..fae0b581ff42 100644
> --- a/drivers/tty/serial/amba-pl010.c
> +++ b/drivers/tty/serial/amba-pl010.c
> @@ -551,7 +551,7 @@ static struct uart_amba_port *amba_ports[UART_NR];
>
>  #ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE
>
> -static void pl010_console_putchar(struct uart_port *port, int ch)
> +static void pl010_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	unsigned int status;
>
> diff --git a/drivers/tty/serial/amba-pl011.c 
> b/drivers/tty/serial/amba-pl011.c
> index ba053a68529f..51ecb050ae40 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -2255,7 +2255,7 @@ static struct uart_amba_port 
> *amba_ports[UART_NR];
>
>  #ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE
>
> -static void pl011_console_putchar(struct uart_port *port, int ch)
> +static void pl011_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	struct uart_amba_port *uap =
>  	    container_of(port, struct uart_amba_port, port);
> @@ -2471,7 +2471,7 @@ static struct console amba_console = {
>
>  #define AMBA_CONSOLE	(&amba_console)
>
> -static void qdf2400_e44_putc(struct uart_port *port, int c)
> +static void qdf2400_e44_putc(struct uart_port *port, unsigned char c)
>  {
>  	while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
>  		cpu_relax();
> @@ -2487,7 +2487,7 @@ static void qdf2400_e44_early_write(struct 
> console *con, const char *s, unsigned
>  	uart_console_write(&dev->port, s, n, qdf2400_e44_putc);
>  }
>
> -static void pl011_putc(struct uart_port *port, int c)
> +static void pl011_putc(struct uart_port *port, unsigned char c)
>  {
>  	while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
>  		cpu_relax();
> diff --git a/drivers/tty/serial/apbuart.c 
> b/drivers/tty/serial/apbuart.c
> index d8c937bdf3f9..9ef82d870ff2 100644
> --- a/drivers/tty/serial/apbuart.c
> +++ b/drivers/tty/serial/apbuart.c
> @@ -413,7 +413,7 @@ static void apbuart_flush_fifo(struct uart_port 
> *port)
>
>  #ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
>
> -static void apbuart_console_putchar(struct uart_port *port, int ch)
> +static void apbuart_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	unsigned int status;
>  	do {
> diff --git a/drivers/tty/serial/ar933x_uart.c 
> b/drivers/tty/serial/ar933x_uart.c
> index 8cabe50c4a33..6269dbf93546 100644
> --- a/drivers/tty/serial/ar933x_uart.c
> +++ b/drivers/tty/serial/ar933x_uart.c
> @@ -613,7 +613,7 @@ static void ar933x_uart_wait_xmitr(struct 
> ar933x_uart_port *up)
>  	} while ((status & AR933X_UART_DATA_TX_CSR) == 0);
>  }
>
> -static void ar933x_uart_console_putchar(struct uart_port *port, int 
> ch)
> +static void ar933x_uart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct ar933x_uart_port *up =
>  		container_of(port, struct ar933x_uart_port, port);
> diff --git a/drivers/tty/serial/arc_uart.c 
> b/drivers/tty/serial/arc_uart.c
> index 596217d10d5c..2a09e92ef9ed 100644
> --- a/drivers/tty/serial/arc_uart.c
> +++ b/drivers/tty/serial/arc_uart.c
> @@ -508,7 +508,7 @@ static int arc_serial_console_setup(struct 
> console *co, char *options)
>  	return uart_set_options(port, co, baud, parity, bits, flow);
>  }
>
> -static void arc_serial_console_putchar(struct uart_port *port, int 
> ch)
> +static void arc_serial_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	while (!(UART_GET_STATUS(port) & TXEMPTY))
>  		cpu_relax();
> diff --git a/drivers/tty/serial/atmel_serial.c 
> b/drivers/tty/serial/atmel_serial.c
> index 73d43919898d..3a45e4fc7993 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -2541,7 +2541,7 @@ static int atmel_init_port(struct 
> atmel_uart_port *atmel_port,
>  }
>
>  #ifdef CONFIG_SERIAL_ATMEL_CONSOLE
> -static void atmel_console_putchar(struct uart_port *port, int ch)
> +static void atmel_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	while (!(atmel_uart_readl(port, ATMEL_US_CSR) & ATMEL_US_TXRDY))
>  		cpu_relax();
> diff --git a/drivers/tty/serial/bcm63xx_uart.c 
> b/drivers/tty/serial/bcm63xx_uart.c
> index 6471a54b616b..53b43174aa40 100644
> --- a/drivers/tty/serial/bcm63xx_uart.c
> +++ b/drivers/tty/serial/bcm63xx_uart.c
> @@ -681,7 +681,7 @@ static void wait_for_xmitr(struct uart_port *port)
>  /*
>   * output given char
>   */
> -static void bcm_console_putchar(struct uart_port *port, int ch)
> +static void bcm_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	wait_for_xmitr(port);
>  	bcm_uart_writel(port, ch, UART_FIFO_REG);
> diff --git a/drivers/tty/serial/clps711x.c 
> b/drivers/tty/serial/clps711x.c
> index 95abc6faa3d5..b9b66ad31a08 100644
> --- a/drivers/tty/serial/clps711x.c
> +++ b/drivers/tty/serial/clps711x.c
> @@ -348,7 +348,7 @@ static const struct uart_ops uart_clps711x_ops = {
>  };
>
>  #ifdef CONFIG_SERIAL_CLPS711X_CONSOLE
> -static void uart_clps711x_console_putchar(struct uart_port *port, 
> int ch)
> +static void uart_clps711x_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct clps711x_port *s = dev_get_drvdata(port->dev);
>  	u32 sysflg = 0;
> diff --git a/drivers/tty/serial/digicolor-usart.c 
> b/drivers/tty/serial/digicolor-usart.c
> index 13ac36e2da4f..6d70fea76bb3 100644
> --- a/drivers/tty/serial/digicolor-usart.c
> +++ b/drivers/tty/serial/digicolor-usart.c
> @@ -381,7 +381,7 @@ static const struct uart_ops digicolor_uart_ops = 
> {
>  	.request_port	= digicolor_uart_request_port,
>  };
>
> -static void digicolor_uart_console_putchar(struct uart_port *port, 
> int ch)
> +static void digicolor_uart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	while (digicolor_uart_tx_full(port))
>  		cpu_relax();
> diff --git a/drivers/tty/serial/dz.c b/drivers/tty/serial/dz.c
> index e9edabc5a211..2e21acf39720 100644
> --- a/drivers/tty/serial/dz.c
> +++ b/drivers/tty/serial/dz.c
> @@ -802,7 +802,7 @@ static void __init dz_init_ports(void)
>   * restored.  Welcome to the world of PDP-11!
>   * 
> -------------------------------------------------------------------
>   */
> -static void dz_console_putchar(struct uart_port *uport, int ch)
> +static void dz_console_putchar(struct uart_port *uport, unsigned 
> char ch)
>  {
>  	struct dz_port *dport = to_dport(uport);
>  	unsigned long flags;
> diff --git a/drivers/tty/serial/earlycon-arm-semihost.c 
> b/drivers/tty/serial/earlycon-arm-semihost.c
> index fa096c10b591..fcdec5f42376 100644
> --- a/drivers/tty/serial/earlycon-arm-semihost.c
> +++ b/drivers/tty/serial/earlycon-arm-semihost.c
> @@ -21,7 +21,7 @@
>  /*
>   * Semihosting-based debug console
>   */
> -static void smh_putc(struct uart_port *port, int c)
> +static void smh_putc(struct uart_port *port, unsigned char c)
>  {
>  #ifdef CONFIG_ARM64
>  	asm volatile("mov  x1, %0\n"
> diff --git a/drivers/tty/serial/earlycon-riscv-sbi.c 
> b/drivers/tty/serial/earlycon-riscv-sbi.c
> index ce81523c3113..27afb0b74ea7 100644
> --- a/drivers/tty/serial/earlycon-riscv-sbi.c
> +++ b/drivers/tty/serial/earlycon-riscv-sbi.c
> @@ -10,7 +10,7 @@
>  #include <linux/serial_core.h>
>  #include <asm/sbi.h>
>
> -static void sbi_putc(struct uart_port *port, int c)
> +static void sbi_putc(struct uart_port *port, unsigned char c)
>  {
>  	sbi_console_putchar(c);
>  }
> diff --git a/drivers/tty/serial/fsl_linflexuart.c 
> b/drivers/tty/serial/fsl_linflexuart.c
> index e72cba085743..98bb0c315e13 100644
> --- a/drivers/tty/serial/fsl_linflexuart.c
> +++ b/drivers/tty/serial/fsl_linflexuart.c
> @@ -553,7 +553,7 @@ static const struct uart_ops linflex_pops = {
>  static struct uart_port *linflex_ports[UART_NR];
>
>  #ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
> -static void linflex_console_putchar(struct uart_port *port, int ch)
> +static void linflex_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	unsigned long cr;
>
> @@ -578,7 +578,7 @@ static void linflex_console_putchar(struct 
> uart_port *port, int ch)
>  	}
>  }
>
> -static void linflex_earlycon_putchar(struct uart_port *port, int ch)
> +static void linflex_earlycon_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	unsigned long flags;
>  	char *ret;
> diff --git a/drivers/tty/serial/fsl_lpuart.c 
> b/drivers/tty/serial/fsl_lpuart.c
> index 7d90c5a530ee..87789872f400 100644
> --- a/drivers/tty/serial/fsl_lpuart.c
> +++ b/drivers/tty/serial/fsl_lpuart.c
> @@ -2333,13 +2333,13 @@ static const struct uart_ops lpuart32_pops = {
>  static struct lpuart_port *lpuart_ports[UART_NR];
>
>  #ifdef CONFIG_SERIAL_FSL_LPUART_CONSOLE
> -static void lpuart_console_putchar(struct uart_port *port, int ch)
> +static void lpuart_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE);
>  	writeb(ch, port->membase + UARTDR);
>  }
>
> -static void lpuart32_console_putchar(struct uart_port *port, int ch)
> +static void lpuart32_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE);
>  	lpuart32_write(port, ch, UARTDATA);
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 0b467ce8d737..fd38e6ed4fda 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -1968,7 +1968,7 @@ static const struct uart_ops imx_uart_pops = {
>  static struct imx_port *imx_uart_ports[UART_NR];
>
>  #if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
> -static void imx_uart_console_putchar(struct uart_port *port, int ch)
> +static void imx_uart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct imx_port *sport = (struct imx_port *)port;
>
> diff --git a/drivers/tty/serial/imx_earlycon.c 
> b/drivers/tty/serial/imx_earlycon.c
> index 795606e1a22f..7aab38b2bd8c 100644
> --- a/drivers/tty/serial/imx_earlycon.c
> +++ b/drivers/tty/serial/imx_earlycon.c
> @@ -16,7 +16,7 @@
>  #define UTS_TXFULL (1<<4) /* TxFIFO full */
>  #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
>
> -static void imx_uart_console_early_putchar(struct uart_port *port, 
> int ch)
> +static void imx_uart_console_early_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL)
>  		cpu_relax();
> diff --git a/drivers/tty/serial/ip22zilog.c 
> b/drivers/tty/serial/ip22zilog.c
> index f4dc5fe4ba92..655e64b26852 100644
> --- a/drivers/tty/serial/ip22zilog.c
> +++ b/drivers/tty/serial/ip22zilog.c
> @@ -990,7 +990,7 @@ static struct zilog_layout * __init get_zs(int 
> chip)
>  #define ZS_PUT_CHAR_MAX_DELAY	2000	/* 10 ms */
>
>  #ifdef CONFIG_SERIAL_IP22_ZILOG_CONSOLE
> -static void ip22zilog_put_char(struct uart_port *port, int ch)
> +static void ip22zilog_put_char(struct uart_port *port, unsigned char 
> ch)
>  {
>  	struct zilog_channel *channel = ZILOG_CHANNEL_FROM_PORT(port);
>  	int loops = ZS_PUT_CHAR_MAX_DELAY;
> diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
> index 3e324d3f0a6d..a3120c3347dd 100644
> --- a/drivers/tty/serial/lantiq.c
> +++ b/drivers/tty/serial/lantiq.c
> @@ -598,7 +598,7 @@ static const struct uart_ops lqasc_pops = {
>
>  #ifdef CONFIG_SERIAL_LANTIQ_CONSOLE
>  static void
> -lqasc_console_putchar(struct uart_port *port, int ch)
> +lqasc_console_putchar(struct uart_port *port, unsigned char ch)
>  {
>  	int fifofree;
>
> diff --git a/drivers/tty/serial/liteuart.c 
> b/drivers/tty/serial/liteuart.c
> index 7f74bf7bdcff..328b50521f14 100644
> --- a/drivers/tty/serial/liteuart.c
> +++ b/drivers/tty/serial/liteuart.c
> @@ -93,7 +93,7 @@ static void liteuart_timer(struct timer_list *t)
>  	mod_timer(&uart->timer, jiffies + uart_poll_timeout(port));
>  }
>
> -static void liteuart_putchar(struct uart_port *port, int ch)
> +static void liteuart_putchar(struct uart_port *port, unsigned char 
> ch)
>  {
>  	while (litex_read8(port->membase + OFF_TXFULL))
>  		cpu_relax();
> diff --git a/drivers/tty/serial/lpc32xx_hs.c 
> b/drivers/tty/serial/lpc32xx_hs.c
> index 54437a087aa0..93140cac1ca1 100644
> --- a/drivers/tty/serial/lpc32xx_hs.c
> +++ b/drivers/tty/serial/lpc32xx_hs.c
> @@ -122,7 +122,7 @@ static void wait_for_xmit_ready(struct uart_port 
> *port)
>  	}
>  }
>
> -static void lpc32xx_hsuart_console_putchar(struct uart_port *port, 
> int ch)
> +static void lpc32xx_hsuart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	wait_for_xmit_ready(port);
>  	writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
> diff --git a/drivers/tty/serial/meson_uart.c 
> b/drivers/tty/serial/meson_uart.c
> index bf6be5468aaf..8fcdfa45cc58 100644
> --- a/drivers/tty/serial/meson_uart.c
> +++ b/drivers/tty/serial/meson_uart.c
> @@ -516,7 +516,7 @@ static void meson_uart_enable_tx_engine(struct 
> uart_port *port)
>  	writel(val, port->membase + AML_UART_CONTROL);
>  }
>
> -static void meson_console_putchar(struct uart_port *port, int ch)
> +static void meson_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	if (!port->membase)
>  		return;
> diff --git a/drivers/tty/serial/milbeaut_usio.c 
> b/drivers/tty/serial/milbeaut_usio.c
> index 8f2cab7f66ad..347088bb380e 100644
> --- a/drivers/tty/serial/milbeaut_usio.c
> +++ b/drivers/tty/serial/milbeaut_usio.c
> @@ -400,7 +400,7 @@ static const struct uart_ops mlb_usio_ops = {
>
>  #ifdef CONFIG_SERIAL_MILBEAUT_USIO_CONSOLE
>
> -static void mlb_usio_console_putchar(struct uart_port *port, int c)
> +static void mlb_usio_console_putchar(struct uart_port *port, 
> unsigned char c)
>  {
>  	while (!(readb(port->membase + MLB_USIO_REG_SSR) & 
> MLB_USIO_SSR_TDRE))
>  		cpu_relax();
> diff --git a/drivers/tty/serial/mps2-uart.c 
> b/drivers/tty/serial/mps2-uart.c
> index 587b42f754cb..5e9429dcc51f 100644
> --- a/drivers/tty/serial/mps2-uart.c
> +++ b/drivers/tty/serial/mps2-uart.c
> @@ -432,7 +432,7 @@ static const struct uart_ops mps2_uart_pops = {
>  static DEFINE_IDR(ports_idr);
>
>  #ifdef CONFIG_SERIAL_MPS2_UART_CONSOLE
> -static void mps2_uart_console_putchar(struct uart_port *port, int ch)
> +static void mps2_uart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	while (mps2_uart_read8(port, UARTn_STATE) & UARTn_STATE_TX_FULL)
>  		cpu_relax();
> @@ -484,7 +484,7 @@ static struct console mps2_uart_console = {
>
>  #define MPS2_SERIAL_CONSOLE (&mps2_uart_console)
>
> -static void mps2_early_putchar(struct uart_port *port, int ch)
> +static void mps2_early_putchar(struct uart_port *port, unsigned char 
> ch)
>  {
>  	while (readb(port->membase + UARTn_STATE) & UARTn_STATE_TX_FULL)
>  		cpu_relax();
> diff --git a/drivers/tty/serial/mvebu-uart.c 
> b/drivers/tty/serial/mvebu-uart.c
> index 2e9263888ddc..aec03f9e1390 100644
> --- a/drivers/tty/serial/mvebu-uart.c
> +++ b/drivers/tty/serial/mvebu-uart.c
> @@ -676,7 +676,7 @@ static const struct uart_ops mvebu_uart_ops = {
>
>  #ifdef CONFIG_SERIAL_MVEBU_CONSOLE
>  /* Early Console */
> -static void mvebu_uart_putc(struct uart_port *port, int c)
> +static void mvebu_uart_putc(struct uart_port *port, unsigned char c)
>  {
>  	unsigned int st;
>
> @@ -737,7 +737,7 @@ static void wait_for_xmite(struct uart_port *port)
>  				  (val & STAT_TX_EMP), 1, 10000);
>  }
>
> -static void mvebu_uart_console_putchar(struct uart_port *port, int 
> ch)
> +static void mvebu_uart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	wait_for_xmitr(port);
>  	writel(ch, port->membase + UART_TSH(port));
> diff --git a/drivers/tty/serial/mxs-auart.c 
> b/drivers/tty/serial/mxs-auart.c
> index ac45f3386e97..1944daf8593a 100644
> --- a/drivers/tty/serial/mxs-auart.c
> +++ b/drivers/tty/serial/mxs-auart.c
> @@ -1305,7 +1305,7 @@ static const struct uart_ops mxs_auart_ops = {
>  static struct mxs_auart_port *auart_port[MXS_AUART_PORTS];
>
>  #ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
> -static void mxs_auart_console_putchar(struct uart_port *port, int ch)
> +static void mxs_auart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct mxs_auart_port *s = to_auart_port(port);
>  	unsigned int to = 1000;
> diff --git a/drivers/tty/serial/omap-serial.c 
> b/drivers/tty/serial/omap-serial.c
> index 0862941862c8..7074670cf81d 100644
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -1194,7 +1194,7 @@ static void omap_serial_early_out(struct 
> uart_port *port, int offset,
>  	writew(value, port->membase + offset);
>  }
>
> -static void omap_serial_early_putc(struct uart_port *port, int c)
> +static void omap_serial_early_putc(struct uart_port *port, unsigned 
> char c)
>  {
>  	unsigned int status;
>
> @@ -1238,7 +1238,7 @@ static struct uart_omap_port 
> *serial_omap_console_ports[OMAP_MAX_HSUART_PORTS];
>
>  static struct uart_driver serial_omap_reg;
>
> -static void serial_omap_console_putchar(struct uart_port *port, int 
> ch)
> +static void serial_omap_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct uart_omap_port *up = to_uart_omap_port(port);
>
> diff --git a/drivers/tty/serial/owl-uart.c 
> b/drivers/tty/serial/owl-uart.c
> index 91f1eb0058d7..5250bd7d390a 100644
> --- a/drivers/tty/serial/owl-uart.c
> +++ b/drivers/tty/serial/owl-uart.c
> @@ -516,7 +516,7 @@ static const struct uart_ops owl_uart_ops = {
>
>  #ifdef CONFIG_SERIAL_OWL_CONSOLE
>
> -static void owl_console_putchar(struct uart_port *port, int ch)
> +static void owl_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	if (!port->membase)
>  		return;
> diff --git a/drivers/tty/serial/pch_uart.c 
> b/drivers/tty/serial/pch_uart.c
> index f0351e6f0ef6..affe71f8b50c 100644
> --- a/drivers/tty/serial/pch_uart.c
> +++ b/drivers/tty/serial/pch_uart.c
> @@ -1600,7 +1600,7 @@ static const struct uart_ops pch_uart_ops = {
>
>  #ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
>
> -static void pch_console_putchar(struct uart_port *port, int ch)
> +static void pch_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	struct eg20t_port *priv =
>  		container_of(port, struct eg20t_port, port);
> diff --git a/drivers/tty/serial/pic32_uart.c 
> b/drivers/tty/serial/pic32_uart.c
> index 0a12fb11e698..b7a3a1b959b1 100644
> --- a/drivers/tty/serial/pic32_uart.c
> +++ b/drivers/tty/serial/pic32_uart.c
> @@ -691,7 +691,7 @@ static const struct uart_ops pic32_uart_ops = {
>
>  #ifdef CONFIG_SERIAL_PIC32_CONSOLE
>  /* output given char */
> -static void pic32_console_putchar(struct uart_port *port, int ch)
> +static void pic32_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	struct pic32_sport *sport = to_pic32_sport(port);
>
> diff --git a/drivers/tty/serial/pmac_zilog.c 
> b/drivers/tty/serial/pmac_zilog.c
> index 5359236b32d6..5d97c201ad88 100644
> --- a/drivers/tty/serial/pmac_zilog.c
> +++ b/drivers/tty/serial/pmac_zilog.c
> @@ -1944,7 +1944,7 @@ static void __exit exit_pmz(void)
>
>  #ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE
>
> -static void pmz_console_putchar(struct uart_port *port, int ch)
> +static void pmz_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	struct uart_pmac_port *uap =
>  		container_of(port, struct uart_pmac_port, port);
> diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
> index 30b099746a75..5d7b7e56661f 100644
> --- a/drivers/tty/serial/pxa.c
> +++ b/drivers/tty/serial/pxa.c
> @@ -619,7 +619,7 @@ static void wait_for_xmitr(struct uart_pxa_port 
> *up)
>  	}
>  }
>
> -static void serial_pxa_console_putchar(struct uart_port *port, int 
> ch)
> +static void serial_pxa_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
>
> diff --git a/drivers/tty/serial/qcom_geni_serial.c 
> b/drivers/tty/serial/qcom_geni_serial.c
> index aedc38893e6c..1543a6028856 100644
> --- a/drivers/tty/serial/qcom_geni_serial.c
> +++ b/drivers/tty/serial/qcom_geni_serial.c
> @@ -397,7 +397,7 @@ static void qcom_geni_serial_poll_put_char(struct 
> uart_port *uport,
>  #endif
>
>  #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
> -static void qcom_geni_serial_wr_char(struct uart_port *uport, int ch)
> +static void qcom_geni_serial_wr_char(struct uart_port *uport, 
> unsigned char ch)
>  {
>  	struct qcom_geni_private_data *private_data = uport->private_data;
>
> diff --git a/drivers/tty/serial/rda-uart.c 
> b/drivers/tty/serial/rda-uart.c
> index d550d8fa2fab..e5f1fded423a 100644
> --- a/drivers/tty/serial/rda-uart.c
> +++ b/drivers/tty/serial/rda-uart.c
> @@ -573,7 +573,7 @@ static const struct uart_ops rda_uart_ops = {
>
>  #ifdef CONFIG_SERIAL_RDA_CONSOLE
>
> -static void rda_console_putchar(struct uart_port *port, int ch)
> +static void rda_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	if (!port->membase)
>  		return;
> diff --git a/drivers/tty/serial/sa1100.c b/drivers/tty/serial/sa1100.c
> index 697b6a002a16..5fe6cccfc1ae 100644
> --- a/drivers/tty/serial/sa1100.c
> +++ b/drivers/tty/serial/sa1100.c
> @@ -695,7 +695,7 @@ void __init sa1100_register_uart(int idx, int 
> port)
>
>
>  #ifdef CONFIG_SERIAL_SA1100_CONSOLE
> -static void sa1100_console_putchar(struct uart_port *port, int ch)
> +static void sa1100_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	struct sa1100_port *sport =
>  		container_of(port, struct sa1100_port, port);
> diff --git a/drivers/tty/serial/samsung_tty.c 
> b/drivers/tty/serial/samsung_tty.c
> index d002a4e48ed9..2bde7bde7116 100644
> --- a/drivers/tty/serial/samsung_tty.c
> +++ b/drivers/tty/serial/samsung_tty.c
> @@ -2478,7 +2478,7 @@ static void s3c24xx_serial_put_poll_char(struct 
> uart_port *port,
>  #endif /* CONFIG_CONSOLE_POLL */
>
>  static void
> -s3c24xx_serial_console_putchar(struct uart_port *port, int ch)
> +s3c24xx_serial_console_putchar(struct uart_port *port, unsigned char 
> ch)
>  {
>  	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
>
> @@ -2965,7 +2965,7 @@ static void samsung_early_busyuart_fifo(struct 
> uart_port *port)
>  		;
>  }
>
> -static void samsung_early_putc(struct uart_port *port, int c)
> +static void samsung_early_putc(struct uart_port *port, unsigned char 
> c)
>  {
>  	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
>  		samsung_early_busyuart_fifo(port);
> diff --git a/drivers/tty/serial/sb1250-duart.c 
> b/drivers/tty/serial/sb1250-duart.c
> index 738df6d9c0d9..2cf8533ef760 100644
> --- a/drivers/tty/serial/sb1250-duart.c
> +++ b/drivers/tty/serial/sb1250-duart.c
> @@ -820,7 +820,7 @@ static void __init sbd_probe_duarts(void)
>   * console output.  The console_lock is held by the caller, so we
>   * shouldn't be interrupted for more console activity.
>   */
> -static void sbd_console_putchar(struct uart_port *uport, int ch)
> +static void sbd_console_putchar(struct uart_port *uport, unsigned 
> char ch)
>  {
>  	struct sbd_port *sport = to_sport(uport);
>
> diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
> index 10cc16a71f26..c56de2e104d4 100644
> --- a/drivers/tty/serial/sccnxp.c
> +++ b/drivers/tty/serial/sccnxp.c
> @@ -828,7 +828,7 @@ static const struct uart_ops sccnxp_ops = {
>  };
>
>  #ifdef CONFIG_SERIAL_SCCNXP_CONSOLE
> -static void sccnxp_console_putchar(struct uart_port *port, int c)
> +static void sccnxp_console_putchar(struct uart_port *port, unsigned 
> char c)
>  {
>  	int tryes = 100000;
>
> diff --git a/drivers/tty/serial/serial_core.c 
> b/drivers/tty/serial/serial_core.c
> index 846192a7b4bf..a1688a341411 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -1911,7 +1911,7 @@ static void uart_port_spin_lock_init(struct 
> uart_port *port)
>   */
>  void uart_console_write(struct uart_port *port, const char *s,
>  			unsigned int count,
> -			void (*putchar)(struct uart_port *, int))
> +			void (*putchar)(struct uart_port *, unsigned char))
>  {
>  	unsigned int i;
>
> diff --git a/drivers/tty/serial/serial_txx9.c 
> b/drivers/tty/serial/serial_txx9.c
> index cd38cf1f03cb..a695e9c1a06a 100644
> --- a/drivers/tty/serial/serial_txx9.c
> +++ b/drivers/tty/serial/serial_txx9.c
> @@ -876,7 +876,7 @@ static void __init 
> serial_txx9_register_ports(struct uart_driver *drv,
>
>  #ifdef CONFIG_SERIAL_TXX9_CONSOLE
>
> -static void serial_txx9_console_putchar(struct uart_port *port, int 
> ch)
> +static void serial_txx9_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct uart_txx9_port *up = to_uart_txx9_port(port);
>
> diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
> index 62a88412e3f6..3029d5fd79a8 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -2957,7 +2957,7 @@ static void sci_cleanup_single(struct sci_port 
> *port)
>
>  #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
>      defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
> -static void serial_console_putchar(struct uart_port *port, int ch)
> +static void serial_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	sci_poll_put_char(port, ch);
>  }
> diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c
> index b79900d0e91a..f5ac14c384c4 100644
> --- a/drivers/tty/serial/sifive.c
> +++ b/drivers/tty/serial/sifive.c
> @@ -756,7 +756,7 @@ static void sifive_serial_poll_put_char(struct 
> uart_port *port,
>   */
>
>  #ifdef CONFIG_SERIAL_EARLYCON
> -static void early_sifive_serial_putc(struct uart_port *port, int c)
> +static void early_sifive_serial_putc(struct uart_port *port, 
> unsigned char c)
>  {
>  	while (__ssp_early_readl(port, SIFIVE_SERIAL_TXDATA_OFFS) &
>  	       SIFIVE_SERIAL_TXDATA_FULL_MASK)
> @@ -800,7 +800,7 @@ OF_EARLYCON_DECLARE(sifive, 
> "sifive,fu540-c000-uart0",
>
>  static struct sifive_serial_port 
> *sifive_serial_console_ports[SIFIVE_SERIAL_MAX_PORTS];
>
> -static void sifive_serial_console_putchar(struct uart_port *port, 
> int ch)
> +static void sifive_serial_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
>
> diff --git a/drivers/tty/serial/sprd_serial.c 
> b/drivers/tty/serial/sprd_serial.c
> index 9a7ae6384edf..4329b9c9cbf0 100644
> --- a/drivers/tty/serial/sprd_serial.c
> +++ b/drivers/tty/serial/sprd_serial.c
> @@ -984,7 +984,7 @@ static void wait_for_xmitr(struct uart_port *port)
>  	} while (status & SPRD_TX_FIFO_CNT_MASK);
>  }
>
> -static void sprd_console_putchar(struct uart_port *port, int ch)
> +static void sprd_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	wait_for_xmitr(port);
>  	serial_out(port, SPRD_TXD, ch);
> @@ -1058,7 +1058,7 @@ console_initcall(sprd_serial_console_init);
>  #define SPRD_CONSOLE	(&sprd_console)
>
>  /* Support for earlycon */
> -static void sprd_putc(struct uart_port *port, int c)
> +static void sprd_putc(struct uart_port *port, unsigned char c)
>  {
>  	unsigned int timeout = SPRD_TIMEOUT;
>
> diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
> index 87e480cc8206..d7fd692286cf 100644
> --- a/drivers/tty/serial/st-asc.c
> +++ b/drivers/tty/serial/st-asc.c
> @@ -854,7 +854,7 @@ static int asc_serial_resume(struct device *dev)
>  
> /*----------------------------------------------------------------------*/
>
>  #ifdef CONFIG_SERIAL_ST_ASC_CONSOLE
> -static void asc_console_putchar(struct uart_port *port, int ch)
> +static void asc_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	unsigned int timeout = 1000000;
>
> diff --git a/drivers/tty/serial/stm32-usart.c 
> b/drivers/tty/serial/stm32-usart.c
> index 1b3a611ac39e..87b5cd4c9743 100644
> --- a/drivers/tty/serial/stm32-usart.c
> +++ b/drivers/tty/serial/stm32-usart.c
> @@ -1641,7 +1641,7 @@ static int stm32_usart_serial_remove(struct 
> platform_device *pdev)
>  }
>
>  #ifdef CONFIG_SERIAL_STM32_CONSOLE
> -static void stm32_usart_console_putchar(struct uart_port *port, int 
> ch)
> +static void stm32_usart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct stm32_port *stm32_port = to_stm32_port(port);
>  	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
> diff --git a/drivers/tty/serial/sunplus-uart.c 
> b/drivers/tty/serial/sunplus-uart.c
> index 450c8e75abb4..b9c55d02bca2 100644
> --- a/drivers/tty/serial/sunplus-uart.c
> +++ b/drivers/tty/serial/sunplus-uart.c
> @@ -500,7 +500,8 @@ static const struct uart_ops sunplus_uart_ops = {
>  #ifdef CONFIG_SERIAL_SUNPLUS_CONSOLE
>  struct sunplus_uart_port *sunplus_console_ports[SUP_UART_NR];
>
> -static void sunplus_uart_console_putchar(struct uart_port *port, int 
> ch)
> +static void sunplus_uart_console_putchar(struct uart_port *port,
> +					 unsigned char ch)
>  {
>  	wait_for_xmitr(port);
>  	sp_uart_put_char(port, ch);
> @@ -732,7 +733,7 @@ static void __exit sunplus_uart_exit(void)
>  module_exit(sunplus_uart_exit);
>
>  #ifdef CONFIG_SERIAL_EARLYCON
> -static void sunplus_uart_putc(struct uart_port *port, int c)
> +static void sunplus_uart_putc(struct uart_port *port, unsigned char 
> c)
>  {
>  	unsigned int val;
>  	int ret;
> diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
> index 92e572634009..6ea52293d9f3 100644
> --- a/drivers/tty/serial/sunsab.c
> +++ b/drivers/tty/serial/sunsab.c
> @@ -846,7 +846,7 @@ static struct uart_sunsab_port *sunsab_ports;
>
>  #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
>
> -static void sunsab_console_putchar(struct uart_port *port, int c)
> +static void sunsab_console_putchar(struct uart_port *port, unsigned 
> char c)
>  {
>  	struct uart_sunsab_port *up =
>  		container_of(port, struct uart_sunsab_port, port);
> diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
> index 98b2f4fb9a99..c31389114b86 100644
> --- a/drivers/tty/serial/sunsu.c
> +++ b/drivers/tty/serial/sunsu.c
> @@ -1281,7 +1281,7 @@ static void wait_for_xmitr(struct 
> uart_sunsu_port *up)
>  	}
>  }
>
> -static void sunsu_console_putchar(struct uart_port *port, int ch)
> +static void sunsu_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	struct uart_sunsu_port *up =
>  		container_of(port, struct uart_sunsu_port, port);
> diff --git a/drivers/tty/serial/sunzilog.c 
> b/drivers/tty/serial/sunzilog.c
> index b714b00d2dad..c14275d83b0b 100644
> --- a/drivers/tty/serial/sunzilog.c
> +++ b/drivers/tty/serial/sunzilog.c
> @@ -100,7 +100,7 @@ struct uart_sunzilog_port {
>  #endif
>  };
>
> -static void sunzilog_putchar(struct uart_port *port, int ch);
> +static void sunzilog_putchar(struct uart_port *port, unsigned char 
> ch);
>
>  #define ZILOG_CHANNEL_FROM_PORT(PORT)	((struct zilog_channel __iomem 
> *)((PORT)->membase))
>  #define UART_ZILOG(PORT)		((struct uart_sunzilog_port *)(PORT))
> @@ -1125,7 +1125,7 @@ static void sunzilog_free_tables(void)
>
>  #define ZS_PUT_CHAR_MAX_DELAY	2000	/* 10 ms */
>
> -static void __maybe_unused sunzilog_putchar(struct uart_port *port, 
> int ch)
> +static void __maybe_unused sunzilog_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	struct zilog_channel __iomem *channel = 
> ZILOG_CHANNEL_FROM_PORT(port);
>  	int loops = ZS_PUT_CHAR_MAX_DELAY;
> diff --git a/drivers/tty/serial/uartlite.c 
> b/drivers/tty/serial/uartlite.c
> index e1fa52d31474..007db67292a2 100644
> --- a/drivers/tty/serial/uartlite.c
> +++ b/drivers/tty/serial/uartlite.c
> @@ -482,7 +482,7 @@ static void ulite_console_wait_tx(struct 
> uart_port *port)
>  			 "timeout waiting for TX buffer empty\n");
>  }
>
> -static void ulite_console_putchar(struct uart_port *port, int ch)
> +static void ulite_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	ulite_console_wait_tx(port);
>  	uart_out32(ch, ULITE_TX, port);
> @@ -558,7 +558,7 @@ static struct console ulite_console = {
>  	.data	= &ulite_uart_driver,
>  };
>
> -static void early_uartlite_putc(struct uart_port *port, int c)
> +static void early_uartlite_putc(struct uart_port *port, unsigned 
> char c)
>  {
>  	/*
>  	 * Limit how many times we'll spin waiting for TX FIFO status.
> diff --git a/drivers/tty/serial/vr41xx_siu.c 
> b/drivers/tty/serial/vr41xx_siu.c
> index 647198b1e2b9..6b303af5ee54 100644
> --- a/drivers/tty/serial/vr41xx_siu.c
> +++ b/drivers/tty/serial/vr41xx_siu.c
> @@ -743,7 +743,7 @@ static void wait_for_xmitr(struct uart_port *port)
>  	}
>  }
>
> -static void siu_console_putchar(struct uart_port *port, int ch)
> +static void siu_console_putchar(struct uart_port *port, unsigned 
> char ch)
>  {
>  	wait_for_xmitr(port);
>  	siu_write(port, UART_TX, ch);
> diff --git a/drivers/tty/serial/vt8500_serial.c 
> b/drivers/tty/serial/vt8500_serial.c
> index 9adfe3dc970f..6f08136ce78a 100644
> --- a/drivers/tty/serial/vt8500_serial.c
> +++ b/drivers/tty/serial/vt8500_serial.c
> @@ -484,7 +484,7 @@ static void wait_for_xmitr(struct uart_port *port)
>  	} while (status & 0x10);
>  }
>
> -static void vt8500_console_putchar(struct uart_port *port, int c)
> +static void vt8500_console_putchar(struct uart_port *port, unsigned 
> char c)
>  {
>  	wait_for_xmitr(port);
>  	writeb(c, port->membase + VT8500_TXFIFO);
> diff --git a/drivers/tty/serial/xilinx_uartps.c 
> b/drivers/tty/serial/xilinx_uartps.c
> index d5e243908d9f..250a1d888eeb 100644
> --- a/drivers/tty/serial/xilinx_uartps.c
> +++ b/drivers/tty/serial/xilinx_uartps.c
> @@ -1142,7 +1142,7 @@ static struct uart_driver cdns_uart_uart_driver;
>   * @port: Handle to the uart port structure
>   * @ch: Character to be written
>   */
> -static void cdns_uart_console_putchar(struct uart_port *port, int ch)
> +static void cdns_uart_console_putchar(struct uart_port *port, 
> unsigned char ch)
>  {
>  	while (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)
>  		cpu_relax();
> diff --git a/drivers/tty/serial/zs.c b/drivers/tty/serial/zs.c
> index 4b4f604646a7..70969bf9d82c 100644
> --- a/drivers/tty/serial/zs.c
> +++ b/drivers/tty/serial/zs.c
> @@ -1124,7 +1124,7 @@ static int __init zs_probe_sccs(void)
>
>
>  #ifdef CONFIG_SERIAL_ZS_CONSOLE
> -static void zs_console_putchar(struct uart_port *uport, int ch)
> +static void zs_console_putchar(struct uart_port *uport, unsigned 
> char ch)
>  {
>  	struct zs_port *zport = to_zport(uport);
>  	struct zs_scc *scc = zport->scc;
> diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
> index 31f7fe527395..14ae35f68abb 100644
> --- a/include/linux/serial_core.h
> +++ b/include/linux/serial_core.h
> @@ -399,7 +399,7 @@ int uart_set_options(struct uart_port *port, 
> struct console *co, int baud,
>  struct tty_driver *uart_console_device(struct console *co, int 
> *index);
>  void uart_console_write(struct uart_port *port, const char *s,
>  			unsigned int count,
> -			void (*putchar)(struct uart_port *, int));
> +			void (*putchar)(struct uart_port *, unsigned char));
>
>  /*
>   * Port/driver registration/removal
> --
> 2.35.1