[Intel-gfx] [PATCH] drm/i915: disable hotplug detect before Ironlake CRT detect

[Zhenyu Wang]

On 2009.12.08 23:33:23 -0800, Eric Anholt wrote:
> This seems like yet another instance of "we need to turn off hotplug
> detection during the detection process" -- can we just do that already?

Sorry for ignore this one... Here's current refreshed patch.

thanks.

From f18aaedb814e3c797bcbbbb885f74ff701dd9d85 Mon Sep 17 00:00:00 2001
From: Zhenyu Wang <zhenyuw at linux.intel.com>
Date: Mon, 25 Jan 2010 10:23:10 +0800
Subject: [PATCH] drm/i915: disable hotplug detect before Ironlake CRT detect

This trys to fix CRT detect loop hang seen on some Ironlake form
factor, to clear up hotplug detect state before taking CRT detect
to make sure next HPD cycle is consistent.

Cc: Stable Team <stable at kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_crt.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index ddefc87..79dd402 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -157,6 +157,9 @@ static bool intel_ironlake_crt_detect_hotplug(struct drm_connector *connector)
 	adpa = I915_READ(PCH_ADPA);
 
 	adpa &= ~ADPA_CRT_HOTPLUG_MASK;
+	/* disable HPD first */
+	I915_WRITE(PCH_ADPA, adpa);
+	(void)I915_READ(PCH_ADPA);
 
 	adpa |= (ADPA_CRT_HOTPLUG_PERIOD_128 |
 			ADPA_CRT_HOTPLUG_WARMUP_10MS |
-- 
1.6.6



-- 
Open Source Technology Center, Intel ltd.

$gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://lists.freedesktop.org/archives/intel-gfx/attachments/20100125/c19d1335/attachment.sig>