[ 3.8.y.z extended stable ] Patch "drm/i915: Preserve the DDI_A_4_LANES bit from the bios" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    drm/i915: Preserve the DDI_A_4_LANES bit from the bios

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 3.8.13.6.

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

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>From 36cbe2a62374d26153fc29a820fdf5cd82ff81be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?St=C3=A9phane=20Marchesin?= <marcheu at chromium.org>
Date: Fri, 12 Jul 2013 13:54:41 -0700
Subject: drm/i915: Preserve the DDI_A_4_LANES bit from the bios
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commit bcf53de4e60d9000b82f541d654529e2902a4c2c upstream.

Otherwise the DDI_A_4_LANES bit gets lost and we can't use > 2 lanes
on eDP. This fixes eDP on hsw with > 2 lanes.

Also s/port_reversal/saved_port_bits/ since the current name is
confusing.

Signed-off-by: Stéphane Marchesin <marcheu at chromium.org>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/gpu/drm/i915/intel_ddi.c | 10 ++++++----
 drivers/gpu/drm/i915/intel_drv.h |  2 +-
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index bd37fe0..b8e53d9 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -681,7 +681,7 @@ static void intel_ddi_mode_set(struct drm_encoder *encoder,
 		struct intel_digital_port *intel_dig_port =
 			enc_to_dig_port(encoder);

-		intel_dp->DP = intel_dig_port->port_reversal |
+		intel_dp->DP = intel_dig_port->saved_port_bits |
 			       DDI_BUF_CTL_ENABLE | DDI_BUF_EMP_400MV_0DB_HSW;
 		switch (intel_dp->lane_count) {
 		case 1:
@@ -1303,7 +1303,8 @@ static void intel_enable_ddi(struct intel_encoder *intel_encoder)
 		 * enabling the port.
 		 */
 		I915_WRITE(DDI_BUF_CTL(port),
-			   intel_dig_port->port_reversal | DDI_BUF_CTL_ENABLE);
+			   intel_dig_port->saved_port_bits |
+			   DDI_BUF_CTL_ENABLE);
 	} else if (type == INTEL_OUTPUT_EDP) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

@@ -1496,8 +1497,9 @@ void intel_ddi_init(struct drm_device *dev, enum port port)
 	intel_encoder->get_hw_state = intel_ddi_get_hw_state;

 	intel_dig_port->port = port;
-	intel_dig_port->port_reversal = I915_READ(DDI_BUF_CTL(port)) &
-					DDI_BUF_PORT_REVERSAL;
+	intel_dig_port->saved_port_bits = I915_READ(DDI_BUF_CTL(port)) &
+					  (DDI_BUF_PORT_REVERSAL |
+					   DDI_A_4_LANES);
 	intel_dig_port->dp.output_reg = DDI_BUF_CTL(port);

 	intel_encoder->type = INTEL_OUTPUT_UNKNOWN;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index a803234..2d8fff3 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -377,7 +377,7 @@ struct intel_dp {
 struct intel_digital_port {
 	struct intel_encoder base;
 	enum port port;
-	u32 port_reversal;
+	u32 saved_port_bits;
 	struct intel_dp dp;
 	struct intel_hdmi hdmi;
 };
--
1.8.1.2