[PATCH] ata: make DVD drive recognisable on systems with Sandybridge CPT chipset

[ming.lei at canonical.com]

From: Ming Lei <tom.leiming at gmail.com>

This quirk patch fixes one kind of bug inside Intel Sandybridge CPT
chipset, see reports from LP794642, LP737388, LP758433, ...

Many guys have reported the problem.

With help from upstream ata maintainer Tejun[1], the problem is found to be
caused by 32bit PIO mode, which is introduced in the commit below:

	commit 0b67c7439fe2a5d76602de36854c88e2beab00b0
	Author: Tejun Heo <tj at kernel.org>
	Date:   Mon Jan 11 17:03:11 2010 +0900

	    ata_piix: enable 32bit PIO on SATA piix

	    Commit 871af1210f13966ab911ed2166e4ab2ce775b99d enabled 32bit PIO
	    for PATA piix but didn't for SATA.  There's no reason not to use 32bit
	    PIO on SATA piix.  Enable it.

	Signed-off-by: Tejun Heo <tj at kernel.org>
	Cc: Alan Cox <alan at lxorguk.ukuu.org.uk>
	Signed-off-by: Jeff Garzik <jgarzik at redhat.com>

so introduce the quirk patch to disable 32bit PIO on SATA piix for Sandybridge CPT
chipset, Alan Cox has agreed on the patch[2].

SRU Justification:

Impact:
        - without the patch, DVD drive can't be recognized on Dell
          optiplex 390.
Fix:
        - After applying the patch, DVD drive can be recognized well
	  on Dell optiplex 390.

BugLink: http://bugs.launchpad.net/bugs/794642

Upstream: [1]/[2]

[1], https://bugzilla.kernel.org/show_bug.cgi?id=40592
[2], http://marc.info/?t=131528297300002&r=1&w=2

Signed-off-by: Ming Lei <tom.leiming at gmail.com>
---
 drivers/ata/ata_piix.c |   12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index 43107e9..eb7ea56 100644
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -341,11 +341,12 @@ static struct ata_port_operations piix_sata_ops = {
 };
 
 static struct ata_port_operations piix_pata_ops = {
-	.inherits		= &piix_sata_ops,
+	.inherits		= &ata_bmdma32_port_ops,
 	.cable_detect		= ata_cable_40wire,
 	.set_piomode		= piix_set_piomode,
 	.set_dmamode		= piix_set_dmamode,
 	.prereset		= piix_pata_prereset,
+	.sff_irq_check		= piix_irq_check,
 };
 
 static struct ata_port_operations piix_vmw_ops = {
@@ -1585,6 +1586,15 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
 				"on poweroff and hibernation\n");
 	}
 
+	/*
+	 * Sandybridge chipset H61/P67/H67 have broken 32 mode up to now
+	 * see https://bugzilla.kernel.org/show_bug.cgi?id=40592
+	 */
+	if (pdev->vendor == PCI_VENDOR_ID_INTEL && pdev->device == 0x1c00)
+		piix_sata_ops.inherits = &ata_bmdma_port_ops;
+	else
+		piix_sata_ops.inherits = &ata_bmdma32_port_ops;
+
 	port_info[0] = piix_port_info[ent->driver_data];
 	port_info[1] = piix_port_info[ent->driver_data];
 
-- 
1.7.4.1