Re: [PATCH 62/86] pata_pdc202xx_old: document known issues

Bartlomiej Zolnierkiewicz
2009-11-25T17:59:34Z

On Wednesday 25 November 2009 06:50:26 pm Jeff Garzik wrote:
> On 11/25/2009 12:46 PM, Alan Cox wrote:
> > On Wed, 25 Nov 2009 18:09:48 +0100
> > Bartlomiej Zolnierkiewicz<bzolnier@gmail.com> wrote:
> >
> >> From: Bartlomiej Zolnierkiewicz<bzolnier@gmail.com>
> >> Subject: [PATCH] pata_pdc202xx_old: document known issues
> >>
> >> Document known issues with the driver to aid distribution makers,
> >> users and developers in making informed decisions instead of wasting
> >> their time needlessly.
> >>
> >> Signed-off-by: Bartlomiej Zolnierkiewicz<bzolnier@gmail.com>
> >> ---
> >> drivers/ata/Kconfig | 4 ++++
> >> 1 file changed, 4 insertions(+)
> >>
> >> Index: b/drivers/ata/Kconfig
> >> ===================================================================
> >> --- a/drivers/ata/Kconfig
> >> +++ b/drivers/ata/Kconfig
> >> @@ -583,6 +583,10 @@ config PATA_PDC_OLD
> >> This option enables support for the Promise 20246, 20262, 20263,
> >> 20265 and 20267 adapters.
> >>
> >> + Known issues:
> >> + - UDMA transfers fail mysteriously on some chipsets
> >> + - ATAPI DMA is unsupported currently
> >
> > Not sure this is useful, because the reports of UDMA failures are lower
> > than most other reports. Should IPV6 have "known issues, mysterious timer
> > list corruption" for example which occurs far more. Not do we list 'no
> > atapi dma' in the help for the IDE SII driver ?
>
> If the chip can support ATAPI DMI, but the driver does not, that
> deserves a comment, even if it's "hardware bugs prevent ATAPI DMA" or
> "ATAPI DMA would require much more code to support, so we did not bother
> for now"
>
> Ditto for things like useful ideas ("consider PIO-over-DMA in SiI 311x")
> and other would-be-nice-to-have ideas. These can serve as projects for
> newbies, or reminders for old-timers.

The problem is that the old driver supported ATAPI DMA so people may have
quite different expectations than in case of never-ever-implemented-ideas.

--
Bartlomiej Zolnierkiewicz