[Linux-parport] [PATCH 1/4] pata_parport: fix pata_parport_devchk

[Sergei Shtylyov]

On 10/3/23 8:07 PM, Ondrej Zary wrote:
[...]

>>> There's a 'x' missing in 0x55 in pata_parport_devchk(), causing the
>>> detection to always fail. Fix it.
>>>
>>> Signed-off-by: Ondrej Zary <linux at zary.sk>
>>
>>    I think we need a Fixes: tag here...
>>
>>> ---
>>>  drivers/ata/pata_parport/pata_parport.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/ata/pata_parport/pata_parport.c b/drivers/ata/pata_parport/pata_parport.c
>>> index 1af64d435d3c..258d189f42e5 100644
>>> --- a/drivers/ata/pata_parport/pata_parport.c
>>> +++ b/drivers/ata/pata_parport/pata_parport.c
>>> @@ -64,7 +64,7 @@ static bool pata_parport_devchk(struct ata_port *ap, unsigned int device)
>>>  	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0xaa);
>>>  	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0x55);
>>>  
>>> -	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 055);
>>> +	pi->proto->write_regr(pi, 0, ATA_REG_NSECT, 0x55);
>>
>>    Oh, Gawd! How did this ever work?! :-/
>>    This bug seems to predate the Big PARIDE move...
> 
> This code was not present in PARIDE - it's my bug.

   Yes, I finally figured -- hence the Fixes: tag I suggested later....

> The function is a clone of ata_devchk() without direct port access.

   The libata's taskfile methods suck big time -- I even used to have
the plans to clean this stuff up at some point...

> It's called only from softreset so nobody notices the breakage until something goes wrong. The CD-865 drive needs a reset to start working.

   I thought the SRST reset is used at the initial detection phase as well...

MBR, Sergey