lkml.org 
[lkml]   [2004]   [Apr]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [RFC][PATCH] 2.4 IDE Serverworks OSB4 DMA patch
Date
On Friday 30 of April 2004 00:09, Patrick Wildi wrote:
> On Thu, 29 Apr 2004, Bartlomiej Zolnierkiewicz wrote:
> > On Thursday 29 of April 2004 21:04, Patrick Wildi wrote:
> > > I have been using a OSB4 chipset based system with a CompactFlash
> > > that supports PIO only and a laptop IBM/Hitachi Travelstar HDD
> > > that supports UDMA.
> > > For both drives, the serverworks code misconfigures the drives:
> > >
> > > - for the CF (hooked up as /dev/hda), svwks_config_drive_xfer_rate()
> > > will not match any tests (drive->autodma = 0, id->capability = 2,
> > > id->field_valid = 1), but the function will then call
> > > hwif->ide_dma_on(drive), which it should not do for this drive.
> > > This patch moves the enabling of DMA up into the DMA section of
> > > the code.
> >
> > Yep, known bug, it is fixed in 2.6.
> >
> > It is present in many other drivers, my 2.6 patch needs to be backported.
>
> Are you the maintainer for 2.4 or to whom should I send the changes?

Send them to me.

> > > - for the Travelstart HDD, the settings coming into
> > > svwks_config_drive_xfer_rate() are: drive->autodma = 32,
> > > id->capability = 15, id->field_valid = 7, id->dma_ultra = 0x43f.
> > > But as this is an OSB4, the hwif->ultra_mask is set to not support
> > > UDMA. Unfortunately in that case svwks_config_drive_xfer_rate()
> > > falls through to the end of the function, instead of trying
> > > other DMA modes.
> >
> > Good catch.
> >
> > It seems the same bug can be present in other drivers too (hint, hint).
> > ;)
>
> I noticed that the piix driver uses the exact same logic. I could
> replicate this part of the patch for other 2.4 drivers. I have no
> way of testing them.
> I can send you a combined patch for 2.4. I am not yet using 2.6.

No problem. :)

Thanks!
Bartlomiej

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:02    [W:0.051 / U:0.036 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site