Patch "drm/i915: refine qemu south bridge detection" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    drm/i915: refine qemu south bridge detection

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-refine-qemu-south-bridge-detection.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From f2e305108faba0c85eb4ba4066599decb675117e Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Mon, 25 Jan 2016 12:02:28 +0100
Subject: drm/i915: refine qemu south bridge detection
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From: Gerd Hoffmann <kraxel@redhat.com>

commit f2e305108faba0c85eb4ba4066599decb675117e upstream.

The test for the qemu q35 south bridge added by commit
"39bfcd52 drm/i915: more virtual south bridge detection"
also matches on real hardware.  Having the check for
virtual systems last in the list is not enough to avoid
that ...

Refine the check by additionally verifying the pci
subsystem id to see whenever it *really* is qemu.

[ v2: fix subvendor tyops ]

Reported-and-tested-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Bruno Wolff III <bruno@wolff.to>
Cc: drm-intel-fixes@lists.freedesktop.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453719748-10944-1-git-send-email-kraxel@redhat.com
(cherry picked from commit 1e859111c128265f8d62b39ff322e42b1ddb5a20)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/i915_drv.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -532,7 +532,9 @@ void intel_detect_pch(struct drm_device
 				DRM_DEBUG_KMS("Found SunrisePoint LP PCH\n");
 				WARN_ON(!IS_SKYLAKE(dev));
 			} else if ((id == INTEL_PCH_P2X_DEVICE_ID_TYPE) ||
-				   (id == INTEL_PCH_QEMU_DEVICE_ID_TYPE)) {
+				   ((id == INTEL_PCH_QEMU_DEVICE_ID_TYPE) &&
+				    pch->subsystem_vendor == 0x1af4 &&
+				    pch->subsystem_device == 0x1100)) {
 				dev_priv->pch_type = intel_virt_detect_pch(dev);
 			} else
 				continue;


Patches currently in stable-queue which might be from kraxel@redhat.com are

queue-4.4/drm-i915-more-virtual-south-bridge-detection.patch
queue-4.4/drm-i915-refine-qemu-south-bridge-detection.patch