At screen depths > 24 bit, the color palettes passed into xf86Randr12CrtcComputeGamma() can have a larger number of slots than the crtc's hardware lut. E.g., at depth 30, 1024 palette slots vs. 256 hw lut slots. This palette size > crtc gamma size case is not handled yet and leads to silent failure, so gamma table updates do not happen.
Add a new subsampling path for this case. This makes lut updates work again, as tested with the xgamma utility (uses XF86VidMode extension) and some RandR based gamma ramp animation. v2: Better resampling when subsampling the palette, as proposed by Ville. Now reaches the max index of the palette and deals with non-power-of-two sizes. Thanks. Signed-off-by: Mario Kleiner <mario.kleiner...@gmail.com> Reviewed-by: Antoine Martin <anto...@nagafix.co.uk> (v1) Cc: <ville.syrj...@linux.intel.com> --- hw/xfree86/modes/xf86RandR12.c | 96 ++++++++++++++++++++++++++++++------------ 1 file changed, 69 insertions(+), 27 deletions(-) diff --git a/hw/xfree86/modes/xf86RandR12.c b/hw/xfree86/modes/xf86RandR12.c index fe8770d..8180483 100644 --- a/hw/xfree86/modes/xf86RandR12.c +++ b/hw/xfree86/modes/xf86RandR12.c @@ -1258,40 +1258,82 @@ xf86RandR12CrtcComputeGamma(xf86CrtcPtr crtc, LOCO *palette, for (shift = 0; (gamma_size << shift) < (1 << 16); shift++); - gamma_slots = crtc->gamma_size / palette_red_size; - for (i = 0; i < palette_red_size; i++) { - value = palette[i].red; - if (gamma_red) - value = gamma_red[value]; - else - value <<= shift; + if (crtc->gamma_size >= palette_red_size) { + /* Upsampling of smaller palette to larger hw lut size */ + gamma_slots = crtc->gamma_size / palette_red_size; + for (i = 0; i < palette_red_size; i++) { + value = palette[i].red; + if (gamma_red) + value = gamma_red[value]; + else + value <<= shift; + + for (j = 0; j < gamma_slots; j++) + crtc->gamma_red[i * gamma_slots + j] = value; + } + } else { + /* Downsampling of larger palette to smaller hw lut size */ + for (i = 0; i < crtc->gamma_size; i++) { + value = palette[i * (palette_red_size - 1) / (crtc->gamma_size - 1)].red; + if (gamma_red) + value = gamma_red[value]; + else + value <<= shift; - for (j = 0; j < gamma_slots; j++) - crtc->gamma_red[i * gamma_slots + j] = value; + crtc->gamma_red[i] = value; + } } - gamma_slots = crtc->gamma_size / palette_green_size; - for (i = 0; i < palette_green_size; i++) { - value = palette[i].green; - if (gamma_green) - value = gamma_green[value]; - else - value <<= shift; + if (crtc->gamma_size >= palette_green_size) { + /* Upsampling of smaller palette to larger hw lut size */ + gamma_slots = crtc->gamma_size / palette_green_size; + for (i = 0; i < palette_green_size; i++) { + value = palette[i].green; + if (gamma_green) + value = gamma_green[value]; + else + value <<= shift; - for (j = 0; j < gamma_slots; j++) - crtc->gamma_green[i * gamma_slots + j] = value; + for (j = 0; j < gamma_slots; j++) + crtc->gamma_green[i * gamma_slots + j] = value; + } + } else { + /* Downsampling of larger palette to smaller hw lut size */ + for (i = 0; i < crtc->gamma_size; i++) { + value = palette[i * (palette_green_size - 1) / (crtc->gamma_size - 1)].green; + if (gamma_green) + value = gamma_green[value]; + else + value <<= shift; + + crtc->gamma_green[i] = value; + } } - gamma_slots = crtc->gamma_size / palette_blue_size; - for (i = 0; i < palette_blue_size; i++) { - value = palette[i].blue; - if (gamma_blue) - value = gamma_blue[value]; - else - value <<= shift; + if (crtc->gamma_size >= palette_blue_size) { + /* Upsampling of smaller palette to larger hw lut size */ + gamma_slots = crtc->gamma_size / palette_blue_size; + for (i = 0; i < palette_blue_size; i++) { + value = palette[i].blue; + if (gamma_blue) + value = gamma_blue[value]; + else + value <<= shift; - for (j = 0; j < gamma_slots; j++) - crtc->gamma_blue[i * gamma_slots + j] = value; + for (j = 0; j < gamma_slots; j++) + crtc->gamma_blue[i * gamma_slots + j] = value; + } + } else { + /* Downsampling of larger palette to smaller hw lut size */ + for (i = 0; i < crtc->gamma_size; i++) { + value = palette[i * (palette_blue_size - 1) / (crtc->gamma_size - 1)].blue; + if (gamma_blue) + value = gamma_blue[value]; + else + value <<= shift; + + crtc->gamma_blue[i] = value; + } } } -- 2.7.4 _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: https://lists.x.org/mailman/listinfo/xorg-devel