From 4cc6feb715c223d59c8cad0dc71bce1a574a2c67 Mon Sep 17 00:00:00 2001 From: Rodrigo Vivi 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 Signed-off-by: Rodrigo Vivi Reviewed-by: Dhinakaran Pandiyan Link: https://patchwork.freedesktop.org/patch/msgid/20170908234534.17986-1-rodrigo.vivi@intel.com Acked-by: Takashi Iwai --- 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)