akpm@xxxxxxxxxxxxxxxxxxxx wrote:
From: Christian Lamparter <chunkeey@xxxxxx>
There is another outstanding issue with ata_piix.c. Intel has never
officially supported anything faster than PATA 100MB/s.
But, the ata_piix.c driver "define" the ICH5 & ICH7 as UDMA6 (aka 133MB/s)
capable. [ Well, no one has probably noticed it before, because there is bug
in do_pata_set_dmamode... Just look at
libata_atapiix_enable_real_udma133.patch and you'll see what wrong with it. ]
Here are Intel's datasheets for the affected chipsets: ICH5 Datasheet:
http://www.intel.com/design/chipsets/datashts/252516.htm (See note on page
183: "... the ICH5 supports reads at the maximum rate of 100MB/s.")
ICH7 Datasheet: http://www.intel.com/design/chipsets/datashts/307013.htm (See
first note on page 190: "... the ICH7 supports reads at the maximum rate of
100MB/s.")
They are two different ways to deal with it:
- Either -
1. replace all ich_pata_133 with ich_pata_100.
(libata_atapiix_disable_udma6.diff - diff from 2.6.22 )
- Or -
2. keep all ich_pata_133 and fix the bug in "do_pata_set_dmamode".
(libata_atapiix_enable_real_udma133.patch - diff from 2.6.22) If there are
any concerns about the safety of the patch patch:
http://lkml.org/lkml/2007/7/6/292 (It was already tested by an Intel
employee, but I guess a bit more user input is necessary here... )
This patch implements 1.
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Cc: Jeff Garzik <jeff@xxxxxxxxxx>
Cc: Tejun Heo <htejun@xxxxxxxxx>
Signed-off-by: Christian Lamparter <chunkeey@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/ata/ata_piix.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
applied
-
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