[Intel-gfx] [PATCH 5/7] drm/i915: handle IVB 3rd pipe during suspend

[Eugeni Dodonov]

We don't need to check 3rd pipe specifically, as it shares PLL with some
other one.

(v2 - for stable kernel: clarify bug description to explain that this
fixes suspend when 3rd pipe is active - fd.o bug #41977).

Upstream commit:
commit 07c1e8c1462fa7324de4c36ae9e55da2abd79cee
Author: Eugeni Dodonov <eugeni.dodonov at intel.com>
Date:   Sat Jan 7 23:40:35 2012 -0200

    drm/i915: handle 3rd pipe

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41977
Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com>
Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>
Signed-off-by: Keith Packard <keithp at keithp.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com>
---
 drivers/gpu/drm/i915/i915_suspend.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index 7886e4f..b815140 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -34,6 +34,10 @@ static bool i915_pipe_enabled(struct drm_device *dev, enum pipe pipe)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	u32	dpll_reg;
 
+	/* On IVB, 3rd pipe shares PLL with another one */
+	if (pipe > 1)
+		return false;
+
 	if (HAS_PCH_SPLIT(dev))
 		dpll_reg = (pipe == PIPE_A) ? _PCH_DPLL_A : _PCH_DPLL_B;
 	else
-- 
1.7.8.4