[lkml]   [2019]   [Jun]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v2 2/3] drm/rockchip: Add optional support for CRTC gamma LUT

On Fri, Jun 21, 2019 at 2:14 PM Ezequiel Garcia <> 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 <>
> ---
> Changes from v1:
> * drop explicit linear LUT after finding a proper
> way to disable gamma correction.
> * avoid setting gamma is the CRTC is not active.
> * s/int/unsigned int as suggested by Jacopo.
> * only enable color management and set gamma size
> if gamma LUT is supported, suggested by Doug.
> * drop the reg-names usage, and instead just use indexed reg
> specifiers, suggested by Doug.
> 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.
> ---
> drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 3 +
> drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 114 ++++++++++++++++++++
> drivers/gpu/drm/rockchip/rockchip_drm_vop.h | 7 ++
> drivers/gpu/drm/rockchip/rockchip_vop_reg.c | 2 +
> 4 files changed, 126 insertions(+)

Looks happy to me now. Since I'm not a DRM expert and almost
certainly don't know much about gamma LUT, take this as you will:

Reviewed-by: Douglas Anderson <>

I'm not in front of my veyron device at the moment, so I can't re-test
exactly this patch so I won't add a Tested-by tag. However, I'll note
that earlier versions worked for the test app I was able to find in
Chrome OS and I'd imagine this one does too.


 \ /
  Last update: 2019-06-24 22:03    [W:0.104 / U:10.636 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site