RE: [PATCH v5 0/8] drm: rcar-du: Add Color Management Module (CMM)

["Kalakodima Venkata Rajesh (RBEI/ECF3)" <VenkataRajesh.Kalakodima@in.bosch.com>]

Hi Jacopo,

Please find comments below.

Best regards,

Rajesh Kv
RBEI/ECF3  

> -----Original Message-----
> From: linux-kernel-owner@vger.kernel.org <linux-kernel-
> owner@vger.kernel.org> On Behalf Of Jacopo Mondi
> Sent: Tuesday, October 15, 2019 4:16 PM
> To: laurent.pinchart@ideasonboard.com;
> kieran.bingham+renesas@ideasonboard.com; geert@linux-m68k.org;
> horms@verge.net.au; uli+renesas@fpond.eu; Kalakodima Venkata Rajesh
> (RBEI/ECF3) <VenkataRajesh.Kalakodima@in.bosch.com>
> Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>; airlied@linux.ie;
> daniel@ffwll.ch; koji.matsuoka.xm@renesas.com; muroya@ksk.co.jp; Harsha
> Manjula Mallikarjun (RBEI/ECF3) <Harsha.ManjulaMallikarjun@in.bosch.com>;
> ezequiel@collabora.com; seanpaul@chromium.org; linux-renesas-
> soc@vger.kernel.org; dri-devel@lists.freedesktop.org; linux-
> kernel@vger.kernel.org
> Subject: [PATCH v5 0/8] drm: rcar-du: Add Color Management Module (CMM)
> 
> References:
> A reference to the v1 cover letter, with some background on the CMM is
> available here:
> https://lkml.org/lkml/2019/6/6/583
> v2:
> https://lore.kernel.org/linux-renesas-soc/20190706140746.29132-10-
> jacopo+renesas@jmondi.org/
> v3:
> https://lore.kernel.org/linux-renesas-soc/20190825135154.11488-1-
> jacopo+renesas@jmondi.org/
> v4:
> https://lore.kernel.org/linux-renesas-soc/20190906135436.10622-1-
> jacopo+renesas@jmondi.org/
> 
> Again, quite a consistent changelog, mostly due to the developments happened
> on Ezequiel's VOP unit following Sean's advices.
> 
> I here implemented the same, and moved the CMM handling to the crtc being
> and enable callbacks. As a result the overall implementation results quite a lot
> simplified, mostly on the CMM driver side.
> 
> I have dropped tags and acks on the CMM driver and CMM enablement patches
> in DU crtc driver because of the number of changes.
> 
> A more detailed change log:
> 
> - Rebased on renesas-devel-2019-10-07-v5.4-rc4
> 
> * Bindings/DT
> - Included Rob's comments on the yaml file license and the use of 'OneOf'
>   in the compatible property description
> - Use the bracketed style suggested by Kieran for the 'renesas,cmm' property
>   introduced in patch 2
> - Re-order the properties in the SoC DTS files as suggested by Kieran
> 
> * CMM/DU
> - As anticipated, moved CMM management to the crtc from the atomic commit
> tail
>   helper where it was implemented in v4
>   This allow to correctly support resume/suspend and proper ordering of the
> CMM
>   enable and setup operations (enable -before- setup)
> - As a consequence the CMM driver is greatly simplified by removing the need
>   to cache the LUT table entries provided to cmm_setup() and later re-apply
>   them at enable time.
> - Better support handling of disabled CMM config option by returning -ENODEV
>   at cmm_init() time as suggested by Kieran.
> 
> * Testing
> I have tested by injecting a color inversion LUT table and enabling/disabling it
> every 50 displayed frames:
> https://jmondi.org/cgit/kmsxx/log/?h=gamma_lut
> 
> CMM functionalities are retained between suspend/resume cycles (tested with
> suspend-to-idle) without requiring a re-programming of the LUT tables.
> 
> Testing with real world use cases might be beneficial. Rajesh are you still
> interested in giving this series a spin

I have tested version v3 of CMM module with a demo application based on libdrm 
library. I could successfully test setting of Gamma LUT.

Next step is to test on full featured graphics stack i.e. involving Weston and OpenGL.
Weston can set Gamma. I have to stop this work for a while due to other high prio activities.
I plan to resume soon.

> 
> Laurent, Kieran, could we fast-track review of this and hopefully try to have it
> merged for v5.5 ?
> 
> Thanks Ezequiel for having suggested me this solution.
> 
> Thanks
>    j
> 
> Jacopo Mondi (8):
>   dt-bindings: display: renesas,cmm: Add R-Car CMM documentation
>   dt-bindings: display, renesas,du: Document cmms property
>   drm: rcar-du: Add support for CMM
>   drm: rcar-du: kms: Initialize CMM instances
>   drm: rcar-du: crtc: Control CMM operations
>   drm: rcar-du: crtc: Register GAMMA_LUT properties
>   arm64: dts: renesas: Add CMM units to Gen3 SoCs
>   drm: rcar-du: kms: Expand comment in vsps parsing routine
> 
>  .../bindings/display/renesas,cmm.yaml         |  67 ++++++
>  .../bindings/display/renesas,du.txt           |   5 +
>  arch/arm64/boot/dts/renesas/r8a7795.dtsi      |  39 ++++
>  arch/arm64/boot/dts/renesas/r8a7796.dtsi      |  31 ++-
>  arch/arm64/boot/dts/renesas/r8a77965.dtsi     |  31 ++-
>  arch/arm64/boot/dts/renesas/r8a77990.dtsi     |  21 ++
>  arch/arm64/boot/dts/renesas/r8a77995.dtsi     |  21 ++
>  drivers/gpu/drm/rcar-du/Kconfig               |   7 +
>  drivers/gpu/drm/rcar-du/Makefile              |   1 +
>  drivers/gpu/drm/rcar-du/rcar_cmm.c            | 198 ++++++++++++++++++
>  drivers/gpu/drm/rcar-du/rcar_cmm.h            |  60 ++++++
>  drivers/gpu/drm/rcar-du/rcar_du_crtc.c        |  89 ++++++++
>  drivers/gpu/drm/rcar-du/rcar_du_crtc.h        |   2 +
>  drivers/gpu/drm/rcar-du/rcar_du_drv.h         |   2 +
>  drivers/gpu/drm/rcar-du/rcar_du_group.c       |   5 +
>  drivers/gpu/drm/rcar-du/rcar_du_group.h       |   2 +
>  drivers/gpu/drm/rcar-du/rcar_du_kms.c         |  82 +++++++-
>  drivers/gpu/drm/rcar-du/rcar_du_regs.h        |   5 +
>  18 files changed, 665 insertions(+), 3 deletions(-)  create mode 100644
> Documentation/devicetree/bindings/display/renesas,cmm.yaml
>  create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.c
>  create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.h
> 
> --
> 2.23.0