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

    Sergei Shtylyov wrote:
    > Hello.

    Hi,

    > 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...

    >> 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)

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

    hehe

    >> 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.

    > 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.

    >> 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...

    >> Index: b/drivers/ide/pci/pdc202xx_old.c
    >> ===================================================================
    >> --- a/drivers/ide/pci/pdc202xx_old.c
    >> +++ b/drivers/ide/pci/pdc202xx_old.c
    >> @@ -339,12 +339,10 @@ static int pdc202xx_config_drive_xfer_ra
    >> 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))
    >> hwif->tuneproc(drive, 5);
    >
    > This driver's tuneproc() method always auto-tunes here instead of
    > setting
    > what it's told too -- I'll send a patch...

    Please do...

    >> Index: b/drivers/ide/pci/siimage.c
    >> ===================================================================
    >> --- a/drivers/ide/pci/siimage.c
    >> +++ b/drivers/ide/pci/siimage.c
    >> @@ -420,12 +420,10 @@ static int siimage_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 also always set PIO mode 4. More mess.

    Yep, same bug as in cmd64x.c.

    >> 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*...

    Thanks,
    Bart

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