From 17e0adf079a3bf2ba16880f6d5473b4ca7881545 Mon Sep 17 00:00:00 2001 From: Mika Kuoppala Date: Tue, 7 Jun 2016 17:19:02 +0300 Subject: [PATCH] drm/i915/edp: Add WaKVMNotificationOnConfigChange:bdw According to bspec this workaround helps to reduce lag and improve performance on edp. Documentation suggests this for bdw and all gen9. However evidence shows that this register is missing on gen9 and causing unclaimed mmio access if we access it. So apply to bdw only where the reg exists and can hold its value. v2: drop skl References: HSD#2134579 Signed-off-by: Mika Kuoppala Reviewed-by: Matthew Auld Link: http://patchwork.freedesktop.org/patch/msgid/1465309159-30531-11-git-send-email-mika.kuoppala@intel.com --- drivers/gpu/drm/i915/i915_reg.h | 3 +++ drivers/gpu/drm/i915/intel_pm.c | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 4ea2253423dc..371b56cb7411 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -6035,6 +6035,9 @@ enum skl_disp_power_wells { #define FORCE_ARB_IDLE_PLANES (1 << 14) #define SKL_EDP_PSR_FIX_RDWRAP (1 << 3) +#define CHICKEN_PAR2_1 _MMIO(0x42090) +#define KVM_CONFIG_CHANGE_NOTIFICATION_SELECT (1 << 14) + #define _CHICKEN_PIPESL_1_A 0x420b0 #define _CHICKEN_PIPESL_1_B 0x420b4 #define HSW_FBCQ_DIS (1 << 22) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index be8a96743e86..45b304e844dd 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -7030,6 +7030,10 @@ static void broadwell_init_clock_gating(struct drm_device *dev) */ I915_WRITE(HSW_GTT_CACHE_EN, GTT_CACHE_EN_ALL); + /* WaKVMNotificationOnConfigChange:bdw */ + I915_WRITE(CHICKEN_PAR2_1, I915_READ(CHICKEN_PAR2_1) + | KVM_CONFIG_CHANGE_NOTIFICATION_SELECT); + lpt_init_clock_gating(dev); } -- 2.20.1