diff mbox series

[1/4] pata_parport: fix pata_parport_devchk

Message ID 20230930191511.24994-2-linux@zary.sk
State New
Headers
Series pata_parport: fix EXP Computer CD-865 with MC-1285B EPP cable |

Commit Message

Ondrej Zary Sept. 30, 2023, 7:15 p.m. UTC 
  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@zary.sk>
---
 drivers/ata/pata_parport/pata_parport.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Sergey Shtylyov Oct. 2, 2023, 6:43 p.m. UTC | #1 
Hello!

On 9/30/23 10:15 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@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...

>  	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0xaa);
>  
>  	nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);
> 

MBR, Sergey
Sergey Shtylyov Oct. 2, 2023, 7:08 p.m. UTC | #2 
On 10/2/23 9:43 PM, Sergey Shtylyov 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@zary.sk>
> 
>    I think we need a Fixes: tag here...

Fixes: 246a1c4c6b7f ("ata: pata_parport: add driver (PARIDE replacement)")

[...]

MBR, Sergey
Ondrej Zary Oct. 3, 2023, 5:07 p.m. UTC | #3 
On Monday 02 October 2023 20:43:09 Sergey Shtylyov wrote:
> Hello!
> 
> On 9/30/23 10:15 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@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.
The function is a clone of ata_devchk() without direct port access.
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.
Sergei Shtylyov Oct. 3, 2023, 5:18 p.m. UTC | #4 
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@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
diff mbox series

Patch

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);
 	pi->proto->write_regr(pi, 0, ATA_REG_LBAL, 0xaa);
 
 	nsect = pi->proto->read_regr(pi, 0, ATA_REG_NSECT);