Re: [PATCH 8/15] ide: disable DMA in ->ide_dma_check for "no IORDY" case

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello.

Bartlomiej Zolnierkiewicz wrote:

> > > [PATCH] ide: disable DMA in ->ide_dma_check for "no IORDY" case

> >   I've looked thru the code, and found more issues with the PIO fallback
> > there. Will try to cook up patches for at least some drivers...

> Great, if possible please base them on top of the IDE tree...

   Erm, I had doubts about it (having in mind that all that code is more of a 
cleanups than fixes). Maybe it'd be a good idea to separate the fix and 
cleanup series somehow...

> > > Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

> > > Index: b/drivers/ide/pci/aec62xx.c
> > > ===================================================================
> > > --- a/drivers/ide/pci/aec62xx.c
> > > +++ b/drivers/ide/pci/aec62xx.c
> > > @@ -214,12 +214,10 @@ static int aec62xx_config_drive_xfer_rat
> > >      if (ide_use_dma(drive) && config_chipset_for_dma(drive))
> > >              return hwif->ide_dma_on(drive);
> > >
> > > -     if (ide_use_fast_pio(drive)) {
> > > +     if (ide_use_fast_pio(drive))
> > >              aec62xx_tune_drive(drive, 5);
> >
> >   This function looks like it's working (thouugh having the wrong limit of
> > PIO5 on auto-tuning) but is unnecassary complex.

> Yes, it seems that there are actually two bugs here:
> * the maximum allowed PIO mode should be PIO4 not PIO5
> * for auto-tuning ("pio" == 255) it incorrectly sets PIO0
>   (255 fails to the default case in the switch statement)

   Yeah, you if you pass 255, it won't work (so, drive->autotune must be 
broken). But the driver itself have the wrong idea of 5 meaning auto-tune, so 
fallback should still work.

> >   Heh, the driver is certainly a rip-off form hpt366.c. What a doubtful
> > example they have chosen... :-)

> hehe

   The driver's authorship explains it all. :-)

> > > Index: b/drivers/ide/pci/atiixp.c
> > > ===================================================================
> > > --- a/drivers/ide/pci/atiixp.c
> > > +++ b/drivers/ide/pci/atiixp.c
> > > @@ -264,10 +264,9 @@ static int atiixp_dma_check(ide_drive_t
> > >              tspeed = ide_get_best_pio_mode(drive, 255, 5, NULL);
> > >              speed = atiixp_dma_2_pio(XFER_PIO_0 + tspeed) + XFER_PIO_0;

> >   It's simply stupid to convert PIO mode to PIO mode. The whole idea is
> > doubtful as well..

> It is side-effect of basing atiixp on piix driver.  Fixing it will allow PIO1
> to be used (good) because atiixp_dma_2_pio() always downgrades PIO1 to PIO0
> (leftover from piix - on Intel chipsets same timings are used for PIO0/1).

> > >              hwif->speedproc(drive, speed);

> >   Well, well, the tuneproc() method can't ahndle auto-tunuing here
> > (255)...

> Yes, definitely a bug.

   Ugh... don't expect patches form me soon though. My first priority is the 
drivers that we support here...

> > And it also doesn't set up drive's own speed. The code seem to be another
> > rip-off from piix.c, repeating all its mistakes... :-)

> :)

> > > Index: b/drivers/ide/pci/cmd64x.c
> > > ===================================================================
> > > --- a/drivers/ide/pci/cmd64x.c
> > > +++ b/drivers/ide/pci/cmd64x.c
> > > @@ -479,12 +479,10 @@ static int cmd64x_config_drive_for_dma (
> > >      if (ide_use_dma(drive) && config_chipset_for_dma(drive))
> > >              return hwif->ide_dma_on(drive);
> > >
> > > -     if (ide_use_fast_pio(drive)) {
> > > +     if (ide_use_fast_pio(drive))
> > >              config_chipset_for_pio(drive, 1);

> >   This function will always set PIO mode 4. Mess.

> Yep.

   I'm going to send the patch for both this and siimage.c...

> > > Index: b/drivers/ide/pci/cs5535.c
> > > ===================================================================
> > > --- a/drivers/ide/pci/cs5535.c
> > > +++ b/drivers/ide/pci/cs5535.c
> > > @@ -206,10 +206,9 @@ static int cs5535_dma_check(ide_drive_t
> > >      if (ide_use_fast_pio(drive)) {
> > >              speed = ide_get_best_pio_mode(drive, 255, 4, NULL);
> > >              cs5535_set_drive(drive, speed);

> >   Could be folded into tuneproc() method call.

> Using ->tuneproc() will also set the PIO mode on the drive
> which is not done currently... 

   Hm, ide_config_drive_speed() is called by both tuneproc() method and 
cs5535_set_drive(), so I saw no issue there...

> > > Index: b/drivers/ide/pci/sis5513.c
> > > ===================================================================
> > > --- a/drivers/ide/pci/sis5513.c
> > > +++ b/drivers/ide/pci/sis5513.c
> > > @@ -678,12 +678,10 @@ static int sis5513_config_xfer_rate(ide_
> > >      if (ide_use_dma(drive) && config_chipset_for_dma(drive))
> > >              return hwif->ide_dma_on(drive);

> > > -     if (ide_use_fast_pio(drive)) {
> > > +     if (ide_use_fast_pio(drive))
> > >              sis5513_tune_drive(drive, 5);

> >    Ugh, PIO fallback effectively always tries to set mode 4 here (thanks
> > it's not 5). Mess.

> Yep, but it seems to be even more complicated since config_art_rwp_pio()
> is a mess^2 - chipset is programmed to the best PIO mode while the
> device is set to PIO4... *sigh*...

   Sorry, this one is low prio for me... :-)

> Thanks,
> Bart

MBR, Sergei
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