[PATCH v4 1/4] drm/msm/dpu: Move TE setup to prepare_for_kickoff()

[Dmitry Baryshkov]

On 21/02/2023 20:42, Jessica Zhang wrote:
> Currently, DPU will enable TE during prepare_commit(). However, this
> will cause a crash and reboot to sahara when trying to read/write to
> register in get_autorefresh_config(), because the core clock rates
> aren't set at that time.
> 
> This used to work because phys_enc->hw_pp is only initialized in mode
> set [1], so the first prepare_commit() will return before any register
> read/write as hw_pp would be NULL.
> 
> However, when we try to implement support for INTF TE, we will run into
> the clock issue described above as hw_intf will *not* be NULL on the
> first prepare_commit(). This is because the initialization of
> dpu_enc->hw_intf has been moved to dpu_encoder_setup() [2].
> 
> To avoid this issue, let's enable TE during prepare_for_kickoff()
> instead as the core clock rates are guaranteed to be set then.
> 
> Depends on: "Implement tearcheck support on INTF block" [3]
> 
> Changes in V3:
> - Added function prototypes
> - Reordered function definitions to make change more legible
> - Removed prepare_commit() function from dpu_encoder_phys_cmd
> 
> Changes in V4:
> - Reworded commit message to be more specific
> - Removed dpu_encoder_phys_cmd_is_ongoing_pptx() prototype
> 
> [1] https://gitlab.freedesktop.org/drm/msm/-/blob/msm-next/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c#L1109
> [2] https://gitlab.freedesktop.org/drm/msm/-/blob/msm-next/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c#L2339
> [3] https://patchwork.freedesktop.org/series/112332/
> 
> Signed-off-by: Jessica Zhang <quic_jesszhan at quicinc.com>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>

-- 
With best wishes
Dmitry