From 4cc6feb715c223d59c8cad0dc71bce1a574a2c67 Mon Sep 17 00:00:00 2001
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Date: Fri, 8 Sep 2017 16:45:33 -0700
Subject: [PATCH] drm/i915/cnp: Don't touch other PCH clock gating bits.
Git-commit: 4cc6feb715c223d59c8cad0dc71bce1a574a2c67
Patch-mainline: v4.15-rc1
References: FATE#322643 bsc#1055900
Don't touch other bits. My bad.
I haven't seen any case where those other bits appeard to be
set before we touch it, but it is safe to avoid touching
other bits we weren't told to touch.
Fixes: 0a46ddd57c9e ("drm/i915/cnp: Wa 1181: Fix Backlight issue")
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908234534.17986-1-rodrigo.vivi@intel.com
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/intel_pm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -8363,7 +8363,8 @@ static void cnp_init_clock_gating(struct
return;
/* Wa #1181 */
- I915_WRITE(SOUTH_DSPCLK_GATE_D, CNP_PWM_CGE_GATING_DISABLE);
+ I915_WRITE(SOUTH_DSPCLK_GATE_D, I915_READ(SOUTH_DSPCLK_GATE_D) |
+ CNP_PWM_CGE_GATING_DISABLE);
}
static void cnl_init_clock_gating(struct drm_i915_private *dev_priv)