<html><body><p>
<pre>
Hi, Jason:
On Wed, 2024-12-11 at 11:47 +0800, Jason-JH.Lin wrote:
> mtk_crtc_finish_page_flip() is used to notify userspace that a
> page flip has been completed, allowing userspace to free the frame
> buffer of the last frame and commit the next frame.
>
> In MediaTek's hardware design for configuring display hardware by using
> GCE, `DRM_EVENT_FLIP_COMPLETE` should be notified to userspace after
> GCE has finished configuring all display hardware settings for each
> atomic_commit().
>
> Currently, mtk_crtc_finish_page_flip() cannot guarantee that GCE has
> configured all the display hardware settings of the last frame.
> Therefore, to increase the accuracy of the timing for notifying
> `DRM_EVENT_FLIP_COMPLETE` to userspace, mtk_crtc_finish_page_flip()
> should be moved to ddp_cmdq_cb().
Reviewed-by: CK Hu <ck.hu@mediatek.com>
>
> Fixes: 7f82d9c43879 ("drm/mediatek: Clear pending flag when cmdq packet is done")
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
> ---
> drivers/gpu/drm/mediatek/mtk_crtc.c | 25 +++++++++++++++++++------
> 1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c
> index eb0e1233ad04..5674f5707cca 100644
> --- a/drivers/gpu/drm/mediatek/mtk_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_crtc.c
> @@ -112,6 +112,11 @@ static void mtk_drm_finish_page_flip(struct mtk_crtc *mtk_crtc)
>
> drm_crtc_handle_vblank(&mtk_crtc->base);
>
> +#if IS_REACHABLE(CONFIG_MTK_CMDQ)
> +if (mtk_crtc->cmdq_client.chan)
> +return;
> +#endif
> +
> spin_lock_irqsave(&mtk_crtc->config_lock, flags);
> if (!mtk_crtc->config_updating && mtk_crtc->pending_needs_vblank) {
> mtk_crtc_finish_page_flip(mtk_crtc);
> @@ -284,10 +289,8 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
> state = to_mtk_crtc_state(mtk_crtc->base.state);
>
> spin_lock_irqsave(&mtk_crtc->config_lock, flags);
> -if (mtk_crtc->config_updating) {
> -spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> +if (mtk_crtc->config_updating)
> goto ddp_cmdq_cb_out;
> -}
>
> state->pending_config = false;
>
> @@ -315,10 +318,15 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
> mtk_crtc->pending_async_planes = false;
> }
>
> -spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> -
> ddp_cmdq_cb_out:
>
> +if (mtk_crtc->pending_needs_vblank) {
> +mtk_crtc_finish_page_flip(mtk_crtc);
> +mtk_crtc->pending_needs_vblank = false;
> +}
> +
> +spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> +
> mtk_crtc->cmdq_vblank_cnt = 0;
> wake_up(&mtk_crtc->cb_blocking_queue);
> }
> @@ -606,13 +614,18 @@ static void mtk_crtc_update_config(struct mtk_crtc *mtk_crtc, bool needs_vblank)
> */
> mtk_crtc->cmdq_vblank_cnt = 3;
>
> +spin_lock_irqsave(&mtk_crtc->config_lock, flags);
> +mtk_crtc->config_updating = false;
> +spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> +
> mbox_send_message(mtk_crtc->cmdq_client.chan, cmdq_handle);
> mbox_client_txdone(mtk_crtc->cmdq_client.chan, 0);
> }
> -#endif
> +#else
> spin_lock_irqsave(&mtk_crtc->config_lock, flags);
> mtk_crtc->config_updating = false;
> spin_unlock_irqrestore(&mtk_crtc->config_lock, flags);
> +#endif
>
> mutex_unlock(&mtk_crtc->hw_lock);
> }
</pre>
</p></body></html><!--type:text--><!--{--><pre>************* MEDIATEK Confidentiality Notice ********************
The information contained in this e-mail message (including any
attachments) may be confidential, proprietary, privileged, or otherwise
exempt from disclosure under applicable laws. It is intended to be
conveyed only to the designated recipient(s). Any use, dissemination,
distribution, printing, retaining or copying of this e-mail (including its
attachments) by unintended recipient(s) is strictly prohibited and may
be unlawful. If you are not an intended recipient of this e-mail, or believe
that you have received this e-mail in error, please notify the sender
immediately (by replying to this e-mail), delete any and all copies of
this e-mail (including any attachments) from your system, and do not
disclose the content of this e-mail to any other person. Thank you!
</pre><!--}-->