On Tue, Sep 08, 2015 at 03:53:28PM +0800, Jun Nie wrote: > 2015-09-08 15:52 GMT+08:00 Jun Nie <jun.nie@xxxxxxxxxx>: > > 2015-09-08 10:23 GMT+08:00 Jun Nie <jun.nie@xxxxxxxxxx>: > >> 2015-09-05 23:57 GMT+08:00 Jun Nie <jun.nie@xxxxxxxxxx>: > >>> Commit 7b753f318d14 ("uart: pl011: Introduce register accessor") > >>> mistakenly used the register LUT i/o accessors for the pl011 > >>> earlycon. Since the port has not been probed at earlycon time, > >>> the struct uart_amba_port (and register LUTs) are uninitialized. > >>> > >>> Use direct register addressing for pl011 earlycon; other h/w supported > >>> by the amba-pl011 driver should declare an alternate earlycon. > >>> > >>> Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> > >>> Signed-off-by: Jun Nie <jun.nie@xxxxxxxxxx> > >>> --- > >>> drivers/tty/serial/amba-pl011.c | 15 +++------------ > >>> 1 file changed, 3 insertions(+), 12 deletions(-) > >>> > >>> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c > >>> index 2af09ab..cce41e0 100644 > >>> --- a/drivers/tty/serial/amba-pl011.c > >>> +++ b/drivers/tty/serial/amba-pl011.c > >>> @@ -326,12 +326,6 @@ static void pl011_writew(struct uart_amba_port *uap, int val, int index) > >>> writew_relaxed(val, uap->port.membase + uap->reg_lut[index]); > >>> } > >>> > >>> -static void pl011_writeb(struct uart_amba_port *uap, u8 val, int index) > >>> -{ > >>> - WARN_ON(index > REG_NR); > >>> - writeb_relaxed(val, uap->port.membase + uap->reg_lut[index]); > >>> -} > >>> - > >>> /* > >>> * Reads up to 256 characters from the FIFO or until it's empty and > >>> * inserts them into the TTY layer. Returns the number of characters > >>> @@ -2348,13 +2342,10 @@ static struct console amba_console = { > >>> > >>> static void pl011_putc(struct uart_port *port, int c) > >>> { > >>> - struct uart_amba_port *uap = > >>> - container_of(port, struct uart_amba_port, port); > >>> - > >>> - while (pl011_readw(uap, REG_FR) & UART01x_FR_TXFF) > >>> + while (readw_relaxed(port->membase + UART01x_FR) & UART01x_FR_TXFF) > >>> ; > >>> - pl011_writeb(uap, c, REG_DR); > >>> - while (pl011_readw(uap, REG_FR) & uap->fr_busy) > >>> + writeb_relaxed(c, port->membase + UART01x_DR); > >>> + while (readw_relaxed(port->membase + UART01x_FR) & UART01x_FR_BUSY) > >>> ; > >>> } > >>> > >>> -- > >>> 1.9.1 > >>> > >> > >> Could anybody help test this earlycon patch on hardware with standard > >> pl011 serial? Your help is appreciated and valuable no matter the > >> previous patch set is carried on or reverted. > >> Thank you very much! > >> > >> Jun > > cc linux-arm-kernel@xxxxxxxxxxxxxxxxxxx in case someone may have > resource to help have a test. Thank you! I tested this patch with the ARM Juno-r1 board, it works. Tested-by: Huang Shijie <shijie.huang@xxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html