[PATCH] drm/i915:icl workaround crc patch

[Aditya Swarup]

Workaround to allow FB passthrough unmodified

Signed-off-by: Aditya Swarup <aditya.swarup at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h      | 1 +
 drivers/gpu/drm/i915/intel_display.c | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index c9b868347481..4713fbb3e021 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7663,6 +7663,7 @@ enum {
 #define _PIPEB_CHICKEN			0x71038
 #define _PIPEC_CHICKEN			0x72038
 #define  PER_PIXEL_ALPHA_BYPASS_EN	(1 << 7)
+#define PIXEL_ROUNDING_TRUNC_FB_PASSTHRU (1 << 15)
 #define PIPE_CHICKEN(pipe)		_MMIO_PIPE(pipe, _PIPEA_CHICKEN,\
 						   _PIPEB_CHICKEN)
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d852cb282060..b2ffd73fb417 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3970,7 +3970,11 @@ static void icl_set_pipe_chicken(struct intel_crtc *crtc)
 	 * and rounding for per-pixel values 00 and 0xff
 	 */
 	tmp |= PER_PIXEL_ALPHA_BYPASS_EN;
-
+	/*
+	 * Display WA #
+	 */
+	printk("++Adi: Pixel round trunc enable for FB passthru \n");
+	tmp |= PIXEL_ROUNDING_TRUNC_FB_PASSTHRU;
 	I915_WRITE(PIPE_CHICKEN(pipe), tmp);
 }
 
-- 
2.17.1