On Tue, 2019-06-18 at 17:47 -0400, Ilia Mirkin wrote: > On Tue, Jun 18, 2019 at 5:43 PM Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx> wrote: > > Add an optional CRTC gamma LUT support, and enable it on RK3288. > > This is currently enabled via a separate address resource, > > which needs to be specified in the devicetree. > > > > The address resource is required because on some SoCs, such as > > RK3288, the LUT address is after the MMU address, and the latter > > is supported by a different driver. This prevents the DRM driver > > from requesting an entire register space. > > > > The current implementation works for RGB 10-bit tables, as that > > is what seems to work on RK3288. > > > > Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx> > > --- > > Changes from RFC: > > * Request (an optional) address resource for the LUT. > > * Drop support for RK3399, which doesn't seem to work > > out of the box and needs more research. > > * Support pass-thru setting when GAMMA_LUT is NULL. > > * Add a check for the gamma size, as suggested by Ilia. > > * Move gamma setting to atomic_commit_tail, as pointed > > out by Jacopo/Laurent, is the correct way. > > --- > > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c > > index 12ed5265a90b..5b6edbe2673f 100644 > > --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c > > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c > > +static void vop_crtc_gamma_set(struct vop *vop, struct drm_crtc *crtc, > > + struct drm_crtc_state *old_state) > > +{ > > + int idle, ret, i; > > + > > + spin_lock(&vop->reg_lock); > > + VOP_REG_SET(vop, common, dsp_lut_en, 0); > > + vop_cfg_done(vop); > > + spin_unlock(&vop->reg_lock); > > + > > + ret = readx_poll_timeout(vop_dsp_lut_is_enable, vop, > > + idle, !idle, 5, 30 * 1000); > > + if (ret) > > + return; > > + > > + spin_lock(&vop->reg_lock); > > + > > + if (crtc->state->gamma_lut) { > > + if (!old_state->gamma_lut || (crtc->state->gamma_lut->base.id != > > + old_state->gamma_lut->base.id)) > > + vop_crtc_write_gamma_lut(vop, crtc); > > + } else { > > + for (i = 0; i < crtc->gamma_size; i++) { > > + u32 word; > > + > > + word = (i << 20) | (i << 10) | i; > > + writel(word, vop->lut_regs + i * 4); > > + } > > Note - I'm not in any way familiar with the hardware, so take with a > grain of salt -- > > Could you just leave dsp_lut_en turned off in this case? > That was the first thing I tried :-) It seems dsp_lut_en is not to enable the CRTC gamma LUT stage, but to enable writing the gamma LUT to the internal RAM. And the specs list no register to enable/disable the gamma LUT. Thanks! Eze