[PATCH xserver 6/7] modesetting: Adapt xf86HandleColorMaps() for > 24 color depth. (v2)

[Mario Kleiner]

This retains old behavior for depths <= 24, but allows gamma
table and colormap updates to work properly at depth 30.

This needs the xf86Randr12CrtcComputeGamma() fix for depth 30
from a previous commit to work. Otherwise the server will work,
but gamma table updates will silently fail, iow. the server
would always run with a default identity gamma lut.

v2: Simplify as proposed by Michel.

Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com>
Reviewed-by: Antoine Martin <antoine at nagafix.co.uk> (v1)
---
 hw/xfree86/drivers/modesetting/drmmode_display.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 9c38563..53a2452 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -2262,13 +2262,17 @@ drmmode_load_palette(ScrnInfoPtr pScrn, int numColors,
 Bool
 drmmode_setup_colormap(ScreenPtr pScreen, ScrnInfoPtr pScrn)
 {
-    xf86DrvMsgVerb(pScrn->scrnIndex, X_INFO, 0, "Initializing kms color map\n");
+    xf86DrvMsgVerb(pScrn->scrnIndex, X_INFO, 0,
+                   "Initializing kms color map for depth %d, %d bpc.\n",
+                   pScrn->depth, pScrn->rgbBits);
     if (!miCreateDefColormap(pScreen))
         return FALSE;
-    /* all radeons support 10 bit CLUTs */
-    if (!xf86HandleColormaps(pScreen, 256, 10, drmmode_load_palette, NULL,
-                CMAP_PALETTED_TRUECOLOR |
-                CMAP_RELOAD_ON_MODE_SWITCH))
+
+    /* Adapt color map size and depth to color depth of screen. */
+    if (!xf86HandleColormaps(pScreen, 1 << pScrn->rgbBits, 10,
+                             drmmode_load_palette, NULL,
+                             CMAP_PALETTED_TRUECOLOR |
+                             CMAP_RELOAD_ON_MODE_SWITCH))
         return FALSE;
     return TRUE;
 }
-- 
2.7.4