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[3.8.y.z,extended,stable] Patch "drm/i915: prefer VBT modes for SVDO-LVDS over EDID" has been added to staging queue

Message ID 1371234824-32262-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa June 14, 2013, 6:33 p.m. UTC
This is a note to let you know that I have just added a patch titled

    drm/i915: prefer VBT modes for SVDO-LVDS over EDID

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.3.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From 795de6db7c0397315b083c6dbf57cecd2c6ad098 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Mon, 10 Jun 2013 09:47:58 +0200
Subject: drm/i915: prefer VBT modes for SVDO-LVDS over EDID

commit c3456fb3e4712d0448592af3c5d644c9472cd3c1 upstream.

In

commit 53d3b4d7778daf15900867336c85d3f8dd70600c
Author: Egbert Eich <eich@suse.de>
Date:   Tue Jun 4 17:13:21 2013 +0200

    drm/i915/sdvo: Use &intel_sdvo->ddc instead of intel_sdvo->i2c for DDC

Egbert Eich fixed a long-standing bug where we simply used a
non-working i2c controller to read the EDID for SDVO-LVDS panels.
Unfortunately some machines seem to not be able to cope with the mode
provided in the EDID. Specifically they seem to not be able to cope
with a 4x pixel mutliplier instead of a 2x one, which seems to have
been worked around by slightly changing the panels native mode in the
VBT so that the dotclock is just barely above 50MHz.

Since it took forever to notice the breakage it's fairly safe to
assume that at least for SDVO-LVDS panels the VBT contains fairly sane
data. So just switch around the order and use VBT modes first.

v2: Also add EDID modes just in case, and spell Egbert correctly.

v3: Elaborate a bit more about what's going on on Chris' machine.

Cc: Egbert Eich <eich@suse.de>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65524
Reported-and-tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/gpu/drm/i915/intel_sdvo.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--
1.8.1.2
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 601dc05..75da731 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1746,10 +1746,13 @@  static void intel_sdvo_get_lvds_modes(struct drm_connector *connector)
 	 * arranged in priority order.
 	 */
 	intel_ddc_get_modes(connector, &intel_sdvo->ddc);
-	if (list_empty(&connector->probed_modes) == false)
-		goto end;

-	/* Fetch modes from VBT */
+	/*
+	 * Fetch modes from VBT. For SDVO prefer the VBT mode since some
+	 * SDVO->LVDS transcoders can't cope with the EDID mode. Since
+	 * drm_mode_probed_add adds the mode at the head of the list we add it
+	 * last.
+	 */
 	if (dev_priv->sdvo_lvds_vbt_mode != NULL) {
 		newmode = drm_mode_duplicate(connector->dev,
 					     dev_priv->sdvo_lvds_vbt_mode);
@@ -1761,7 +1764,6 @@  static void intel_sdvo_get_lvds_modes(struct drm_connector *connector)
 		}
 	}

-end:
 	list_for_each_entry(newmode, &connector->probed_modes, head) {
 		if (newmode->type & DRM_MODE_TYPE_PREFERRED) {
 			intel_sdvo->sdvo_lvds_fixed_mode =