From 4366f3b5f5a971cf348c298716b2cb29aab6ef4f Mon Sep 17 00:00:00 2001 From: Mario Kleiner Date: Sat, 7 Jun 2014 03:38:11 +0200 Subject: drm/radeon: Bypass hw lut's for > 8 bpc framebuffer scanout. The hardware lut's only have 256 slots for indexing by a 8 bpc framebuffer. In 10 bpc scanout modes, framebuffer color values would get truncated to their 8 msb's, thereby losing the extra precision afforded by a 10 bpc framebuffer. To retain full precision, bypass the hw lut in 10 bpc scanout mode. Signed-off-by: Mario Kleiner Signed-off-by: Alex Deucher --- drivers/gpu/drm/radeon/radeon_display.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/radeon/radeon_display.c') diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c index 5ed617056b9c..4db26420f38a 100644 --- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -66,7 +66,8 @@ static void avivo_crtc_load_lut(struct drm_crtc *crtc) (radeon_crtc->lut_b[i] << 0)); } - WREG32(AVIVO_D1GRPH_LUT_SEL + radeon_crtc->crtc_offset, radeon_crtc->crtc_id); + /* Only change bit 0 of LUT_SEL, other bits are set elsewhere */ + WREG32_P(AVIVO_D1GRPH_LUT_SEL + radeon_crtc->crtc_offset, radeon_crtc->crtc_id, ~1); } static void dce4_crtc_load_lut(struct drm_crtc *crtc) -- cgit v1.2.3