drm: Initialize a linear gamma table by default

Code stolen from gma500.

This is just a minor bit of safety code that I spotted and figured it
might be useful if we put it into the core. This is to make the
get_gamma ioctl reflect likely reality even before the first set_gamma
ioctl call.

v2 on irc: Extend commit message per Maarten's suggestions.

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459331485-28376-2-git-send-email-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter 2016-03-30 11:51:16 +02:00
parent 1bd816f120
commit cf48e2921e
2 changed files with 13 additions and 7 deletions

View file

@ -5139,6 +5139,9 @@ EXPORT_SYMBOL(drm_mode_connector_attach_encoder);
int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
int gamma_size)
{
uint16_t *r_base, *g_base, *b_base;
int i;
crtc->gamma_size = gamma_size;
crtc->gamma_store = kcalloc(gamma_size, sizeof(uint16_t) * 3,
@ -5148,6 +5151,16 @@ int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
return -ENOMEM;
}
r_base = crtc->gamma_store;
g_base = r_base + gamma_size;
b_base = g_base + gamma_size;
for (i = 0; i < gamma_size; i++) {
r_base[i] = i << 8;
g_base[i] = i << 8;
b_base[i] = i << 8;
}
return 0;
}
EXPORT_SYMBOL(drm_mode_crtc_set_gamma_size);

View file

@ -491,7 +491,6 @@ void psb_intel_crtc_init(struct drm_device *dev, int pipe,
struct drm_psb_private *dev_priv = dev->dev_private;
struct gma_crtc *gma_crtc;
int i;
uint16_t *r_base, *g_base, *b_base;
/* We allocate a extra array of drm_connector pointers
* for fbdev after the crtc */
@ -519,16 +518,10 @@ void psb_intel_crtc_init(struct drm_device *dev, int pipe,
gma_crtc->pipe = pipe;
gma_crtc->plane = pipe;
r_base = gma_crtc->base.gamma_store;
g_base = r_base + 256;
b_base = g_base + 256;
for (i = 0; i < 256; i++) {
gma_crtc->lut_r[i] = i;
gma_crtc->lut_g[i] = i;
gma_crtc->lut_b[i] = i;
r_base[i] = i << 8;
g_base[i] = i << 8;
b_base[i] = i << 8;
gma_crtc->lut_adj[i] = 0;
}