[PATCH] ide: revert "ide: fix drive side 80c cable check, take 2" for now

[PATCH] ide: revert "ide: fix drive side 80c cable check, take 2" for now

[Bartlomiej Zolnierkiewicz]

[PATCH] ide: revert "ide: fix drive side 80c cable check, take 2" for now

"ide: fix drive side 80c cable check, take 2" patch from Tejun Heo (commit
fab59375b9543f84d1714f7dd00f5d11e531bd3e) fixed 80c bit test (bit13 of word93)
but we also need to fix master/slave IDENTIFY order (slave device should be
probed first in order to make it release PDIAG- signal) and we should also
check for pre-ATA3 slave devices (which may not release PDIAG- signal).

[ Unfortunately the fact that IDE driver doesn't reset devices itself helps
  only a bit as it seems that some BIOS-es reset ATA devices after programming
  the chipset, some BIOS-es can be set to not probe/configure selected devices,
  there may be no BIOS in case of add-on cards etc. ]

Since we are quite late in the release cycle and the required changes will
affect a lot of systems just revert the fix for now.

[ Please also see libata commit f31f0cc2f0b7527072d94d02da332d9bb8d7d94c. ]

Thanks goes out to Fernando Mitio Yamada for reporting the problem
and patiently testing patches.

Cc: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
---

 drivers/ide/ide-iops.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Index: b/drivers/ide/ide-iops.c
===================================================================
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -583,8 +583,12 @@ u8 eighty_ninty_three (ide_drive_t *driv
 	if(!(drive->id->hw_config & 0x4000))
 		return 0;
 #endif /* CONFIG_IDEDMA_IVB */
-	if (!(drive->id->hw_config & 0x2000))
-		return 0;
+	/*
+	 * FIXME:
+	 * - change master/slave IDENTIFY order
+	 * - force bit13 (80c cable present) check
+	 *   (unless the slave device is pre-ATA3)
+	 */
 	return 1;
 }
 

Re: [PATCH] ide: revert "ide: fix drive side 80c cable check, take 2" for now

[Tejun Heo]

Bartlomiej Zolnierkiewicz wrote:
> [PATCH] ide: revert "ide: fix drive side 80c cable check, take 2" for now
> 
> "ide: fix drive side 80c cable check, take 2" patch from Tejun Heo (commit
> fab59375b9543f84d1714f7dd00f5d11e531bd3e) fixed 80c bit test (bit13 of word93)
> but we also need to fix master/slave IDENTIFY order (slave device should be
> probed first in order to make it release PDIAG- signal) and we should also
> check for pre-ATA3 slave devices (which may not release PDIAG- signal).
> 
> [ Unfortunately the fact that IDE driver doesn't reset devices itself helps
>   only a bit as it seems that some BIOS-es reset ATA devices after programming
>   the chipset, some BIOS-es can be set to not probe/configure selected devices,
>   there may be no BIOS in case of add-on cards etc. ]
> 
> Since we are quite late in the release cycle and the required changes will
> affect a lot of systems just revert the fix for now.
> 
> [ Please also see libata commit f31f0cc2f0b7527072d94d02da332d9bb8d7d94c. ]
> 
> Thanks goes out to Fernando Mitio Yamada for reporting the problem
> and patiently testing patches.
> 
> Cc: Tejun Heo <htejun@gmail.com>
> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Ackec-by: Tejun Heo <htejun@gmail.com>

Never suspected it could cause this much problem.  :-(

-- 
tejun