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!
Jun
--
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
