[PATCH v5 0/3] drm/vkms: Introduces writeback support

[Melissa Wen]

Hi Rodrigo,

Nice work!

I tested this on the kms_writeback set of subtests and works fine.

I have also checked it on the other IGT tests that I usually uses:
- kms_cursor_crc/cursor-alpha-transparent was affected by a small
  problem in the bitmap_clear of the get_pixel_from_buffer function,
  that I pointed out inline. Please, check it.
- kms_flip and kms_pipe_crc_basic works as expected (was not affected).

Best regards,

Melissa Wen

On 08/24, Rodrigo Siqueira wrote:
> This is the V5 version of a series that introduces the writeback support
> to VKMS. The first two patches of this series are a pre-work for the
> latest patch that adds the writeback connector, this patchset can be seen
> in two parts: 
> 
> * A pre-work that aims to make vkms composer operations a little bit more
>   generic; these patches try to centralize the vkms framebuffer operations.
> * The final patch enables the support for writeback in vkms.
> 
> In the previous review, Emil suggested multiple changes in the series. I
> tried to apply most of the recommendations except for some suggestions
> which I was not able to incorporate due to compilation issues, or other
> suggestions that may complicate this series review. I left some changes
> for future patches for keeping this patchset simple with the hope of
> landing this feature soon in order to support VKMS user's requirements.
> Emil, let me know if you want me to change any other thing.
> 
> It is important to highlight that from the previous series to the
> current version of this patchset we had some changes in the VKMS that
> made it unstable.  In particular, our previous writeback series stopped
> working properly due to changes in our commit tail.  Thanks to Melissa
> working in the instability issue and her latest fixes to VKMS, I finally
> could update writeback and make it work again. The main update in the
> latest patch is the use of vkms_set_composer when the writeback work
> starts (enable composer) and after the writeback end (disable composer).
> 
> Best Regard
> 
> Rodrigo Siqueira (3):
>   drm/vkms: Decouple crc operations from composer
>   drm/vkms: Compute CRC without change input data
>   drm/vkms: Add support for writeback
> 
>  drivers/gpu/drm/vkms/Makefile         |   9 +-
>  drivers/gpu/drm/vkms/vkms_composer.c  | 102 +++++++++++-------
>  drivers/gpu/drm/vkms/vkms_drv.h       |  11 +-
>  drivers/gpu/drm/vkms/vkms_output.c    |   4 +
>  drivers/gpu/drm/vkms/vkms_writeback.c | 143 ++++++++++++++++++++++++++
>  5 files changed, 231 insertions(+), 38 deletions(-)
>  create mode 100644 drivers/gpu/drm/vkms/vkms_writeback.c
> 
> -- 
> 2.28.0
>