Re: 2.6.24-rc2: Reported regressions from 2.6.23 (updated)

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Sunday 11 November 2007, Alan Cox wrote:

> > Subject		: 2.6.24-rc1: pata_amd fails to detect 80-pin wire
> > Submitter	: "Thomas Lindroth" <thomas.lindroth@gmail.com>
> > References	: http://lkml.org/lkml/2007/11/7/152
> > 		  http://bugzilla.kernel.org/show_bug.cgi?id=9322

http://lkml.org/lkml/2007/10/12/537

The regression itself has been foreseen a month ago and it is quite
sad that it is still not fixed...

> Tejun is looking into this - its not trivial so may be 2.6.25 material.
> Similar reports for some other controllers (notably VIA).

We may fix the regression in a bit different way for now and give Tejun
some more time for the complete rework of the cable detection code.

[PATCH] pata_amd/pata_via: de-couple programming of PIO/MWDMA and UDMA timings

* Don't program UDMA timings when programming PIO or MWDMA modes.

  This has also a nice side-effect of fixing regression added by commit
  681c80b5d96076f447e8101ac4325c82d8dce508 ("libata: correct handling of
  SRST reset sequences") (->set_piomode method for PIO0 is called before
  ->cable_detect method which checks UDMA timings to get the cable type).

* Bump driver version.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
---
Untested, please don't merge until it is confirmed to fix the problem.

 drivers/ata/pata_amd.c |    5 +++--
 drivers/ata/pata_via.c |    4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

Index: b/drivers/ata/pata_amd.c
===================================================================
--- a/drivers/ata/pata_amd.c
+++ b/drivers/ata/pata_amd.c
@@ -25,7 +25,7 @@
 #include <linux/libata.h>
 
 #define DRV_NAME "pata_amd"
-#define DRV_VERSION "0.3.9"
+#define DRV_VERSION "0.3.10"
 
 /**
  *	timing_setup		-	shared timing computation and load
@@ -115,7 +115,8 @@ static void timing_setup(struct ata_port
 	}
 
 	/* UDMA timing */
-	pci_write_config_byte(pdev, offset + 0x10 + (3 - dn), t);
+	if (at.udma)
+		pci_write_config_byte(pdev, offset + 0x10 + (3 - dn), t);
 }
 
 /**
Index: b/drivers/ata/pata_via.c
===================================================================
--- a/drivers/ata/pata_via.c
+++ b/drivers/ata/pata_via.c
@@ -63,7 +63,7 @@
 #include <linux/dmi.h>
 
 #define DRV_NAME "pata_via"
-#define DRV_VERSION "0.3.2"
+#define DRV_VERSION "0.3.3"
 
 /*
  *	The following comes directly from Vojtech Pavlik's ide/pci/via82cxxx
@@ -296,7 +296,7 @@ static void via_do_set_mode(struct ata_p
 	}
 
 	/* Set UDMA unless device is not UDMA capable */
-	if (udma_type) {
+	if (udma_type && t.udma) {
 		u8 cable80_status;
 
 		/* Get 80-wire cable detection bit */