| Message ID | 20241210032820.10958-1-jason-jh.lin@mediatek.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] drm/mediatek: Move mtk_crtc_finish_page_flip() to ddp_cmdq_cb() | expand |
Hi, Jason: On Tue, 2024-12-10 at 11:28 +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(). > > 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 | 29 +++++++++++++++++++++-------- > 1 file changed, 21 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c > index eb0e1233ad04..dabc2f8086b6 100644 > --- a/drivers/gpu/drm/mediatek/mtk_crtc.c > +++ b/drivers/gpu/drm/mediatek/mtk_crtc.c > @@ -109,9 +109,14 @@ static void mtk_crtc_finish_page_flip(struct mtk_crtc *mtk_crtc) > static void mtk_drm_finish_page_flip(struct mtk_crtc *mtk_crtc) > { > unsigned long flags; > + struct drm_crtc *crtc = &mtk_crtc->base; > + struct mtk_drm_private *priv = crtc->dev->dev_private; > > drm_crtc_handle_vblank(&mtk_crtc->base); > > + if (!priv->data->shadow_register) > + return; > + I forget one case. For the CPU case (SoC has no shadow register and CONFIG_MTK_CMDQ is not enable), this driver should still work. CPU case is not a usual case, but it could be used in some verification case. So the condition may be #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); > } > @@ -584,6 +592,10 @@ static void mtk_crtc_update_config(struct mtk_crtc *mtk_crtc, bool needs_vblank) > mtk_mutex_acquire(mtk_crtc->mutex); > mtk_crtc_ddp_config(crtc, NULL); > mtk_mutex_release(mtk_crtc->mutex); > + > + spin_lock_irqsave(&mtk_crtc->config_lock, flags); > + mtk_crtc->config_updating = false; > + spin_unlock_irqrestore(&mtk_crtc->config_lock, flags); > } > #if IS_REACHABLE(CONFIG_MTK_CMDQ) > if (mtk_crtc->cmdq_client.chan) { > @@ -606,13 +618,14 @@ 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 > - spin_lock_irqsave(&mtk_crtc->config_lock, flags); > - mtk_crtc->config_updating = false; > - spin_unlock_irqrestore(&mtk_crtc->config_lock, flags); For the CPU case (SoC has no shadow register and CONFIG_MTK_CMDQ is not enable), This code is necessary. Maybe keep these code or some modification for CPU case. Regards, CK > > mutex_unlock(&mtk_crtc->hw_lock); > }
Hi CK, [snip] > > @@ -109,9 +109,14 @@ static void mtk_crtc_finish_page_flip(struct > > mtk_crtc *mtk_crtc) > > static void mtk_drm_finish_page_flip(struct mtk_crtc *mtk_crtc) > > { > > unsigned long flags; > > + struct drm_crtc *crtc = &mtk_crtc->base; > > + struct mtk_drm_private *priv = crtc->dev->dev_private; > > > > drm_crtc_handle_vblank(&mtk_crtc->base); > > > > + if (!priv->data->shadow_register) > > + return; > > + > > I forget one case. > For the CPU case (SoC has no shadow register and CONFIG_MTK_CMDQ is > not enable), > this driver should still work. > CPU case is not a usual case, but it could be used in some > verification case. > So the condition may be > > #if IS_REACHABLE(CONFIG_MTK_CMDQ) > if (mtk_crtc->cmdq_client.chan) > return; > #endif > OK, I'll change the condition like this. > > 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); [snip] > > @@ -584,6 +592,10 @@ static void mtk_crtc_update_config(struct > > mtk_crtc *mtk_crtc, bool needs_vblank) > > mtk_mutex_acquire(mtk_crtc->mutex); > > mtk_crtc_ddp_config(crtc, NULL); > > mtk_mutex_release(mtk_crtc->mutex); > > + > > + spin_lock_irqsave(&mtk_crtc->config_lock, flags); > > + mtk_crtc->config_updating = false; > > + spin_unlock_irqrestore(&mtk_crtc->config_lock, flags); > > } > > #if IS_REACHABLE(CONFIG_MTK_CMDQ) > > if (mtk_crtc->cmdq_client.chan) { > > @@ -606,13 +618,14 @@ 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 > > - spin_lock_irqsave(&mtk_crtc->config_lock, flags); > > - mtk_crtc->config_updating = false; > > - spin_unlock_irqrestore(&mtk_crtc->config_lock, flags); > > For the CPU case (SoC has no shadow register and CONFIG_MTK_CMDQ is > not enable), > This code is necessary. > Maybe keep these code or some modification for CPU case. > OK, I'll keep the original flow and only modify for IS_REACHABLE(CONFIG_MTK_CMDQ) case. Regards, Jason-JH.lin > Regards, > CK
diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c index eb0e1233ad04..dabc2f8086b6 100644 --- a/drivers/gpu/drm/mediatek/mtk_crtc.c +++ b/drivers/gpu/drm/mediatek/mtk_crtc.c @@ -109,9 +109,14 @@ static void mtk_crtc_finish_page_flip(struct mtk_crtc *mtk_crtc) static void mtk_drm_finish_page_flip(struct mtk_crtc *mtk_crtc) { unsigned long flags; + struct drm_crtc *crtc = &mtk_crtc->base; + struct mtk_drm_private *priv = crtc->dev->dev_private; drm_crtc_handle_vblank(&mtk_crtc->base); + if (!priv->data->shadow_register) + return; + 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); } @@ -584,6 +592,10 @@ static void mtk_crtc_update_config(struct mtk_crtc *mtk_crtc, bool needs_vblank) mtk_mutex_acquire(mtk_crtc->mutex); mtk_crtc_ddp_config(crtc, NULL); mtk_mutex_release(mtk_crtc->mutex); + + spin_lock_irqsave(&mtk_crtc->config_lock, flags); + mtk_crtc->config_updating = false; + spin_unlock_irqrestore(&mtk_crtc->config_lock, flags); } #if IS_REACHABLE(CONFIG_MTK_CMDQ) if (mtk_crtc->cmdq_client.chan) { @@ -606,13 +618,14 @@ 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 - spin_lock_irqsave(&mtk_crtc->config_lock, flags); - mtk_crtc->config_updating = false; - spin_unlock_irqrestore(&mtk_crtc->config_lock, flags); mutex_unlock(&mtk_crtc->hw_lock); }
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(). 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 | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-)