On Thu, Oct 10, 2019 at 12:01 PM Sean Paul sean@poorly.run wrote:
+static int vop_crtc_atomic_check(struct drm_crtc *crtc,
struct drm_crtc_state *crtc_state)+{
struct vop *vop = to_vop(crtc);if (vop->lut_regs && crtc_state->color_mgmt_changed &&crtc_state->gamma_lut) {unsigned int len;len = drm_color_lut_size(crtc_state->gamma_lut);if (len != crtc->gamma_size) {DRM_DEBUG_KMS("Invalid LUT size; got %d, expected %d\n",len, crtc->gamma_size);return -EINVAL;}Overflow is avoided in drm_mode_gamma_set_ioctl(), so I don't think you need this function.
But that only applies to the legacy path. Isn't this needed to ensure a gamma blob has the right size?
Yeah, good point, we check the element size in the atomic path, but not the max size. I haven't looked at enough color lut stuff to have an opinion whether this check would be useful in a helper function or not, something to consider, I suppose.
Some implementations support multiple sizes (e.g. 256 and 1024) but not anything in between. It would be difficult to expose this generically, I would imagine. The 256 size is kind of special, since basically all legacy usage assumes that 256 is the one true quantity of LUT entries...
-ilia