Re: [PATCH v6 13/25] drm/msm: Compute dumb-buffer sizes with drm_mode_size_dumb()

Dmitry Baryshkov
2025-11-02T16:39:34Z

On Thu, Aug 21, 2025 at 10:17:20AM +0200, Thomas Zimmermann wrote:
> Call drm_mode_size_dumb() to compute dumb-buffer scanline pitch
> and buffer size. Alignment is specified in bytes, but the hardware
> requires the scanline pitch to be a multiple of 32 pixels. Therefore
> compute the byte size of 32 pixels in the given color mode and align
> the pitch accordingly. This replaces the existing code in the driver's
> align_pitch() helper.
>
> v3:
> - clarify pitch alignment in commit message (Dmitry)
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Cc: Rob Clark <robdclark@gmail.com>
> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Cc: Sean Paul <sean@poorly.run>
> Cc: Marijn Suijten <marijn.suijten@somainline.org>
> ---
> drivers/gpu/drm/msm/msm_gem.c | 27 +++++++++++++++++++++++++--
> 1 file changed, 25 insertions(+), 2 deletions(-)
>

This broke kms_getfb@getfb-reject-nv12 and kms_getfb@getfb2-accept-nv12
IGT tests. I'll submit a fix separately.

--
With best wishes
Dmitry