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!
Jun
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