drm: psuedocolor support for ARGB modes

If there is an alpha channel, need to mask in 1's in the alpha channel
to prevent the fb from being completely transparent.

Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 6977a1ce9d98..d421f9d58d46 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -627,6 +627,11 @@ static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
                 value = (red << info->var.red.offset) |
                         (green << info->var.green.offset) |
                         (blue << info->var.blue.offset);
+                if (info->var.transp.length > 0) {
+                        u32 mask = (1 << info->var.transp.length) - 1;
+                        mask <<= info->var.transp.offset;
+                        value |= mask;
+                }
                 palette[regno] = value;
                 return 0;
         }