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 <mario.kleiner.de@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Mario Kleiner
2014-06-07 03:38:11 +02:00
committed by Alex Deucher
parent 8bae42769d
commit 4366f3b5f5
4 changed files with 32 additions and 1 deletions

View File

@@ -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)