6.6-stable review patch. If anyone has any objections, please let me know.
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From: Jason-JH.Lin jason-jh.lin@mediatek.com
[ Upstream commit fe30bae552ce27b9fefe0b12db1544e73d07325f ]
In mtk_crtc_ddp_config(), mtk_crtc will use some configuration flags to generate instructions to cmdq_handle, such as: state->pending_config mtk_crtc->pending_planes plane_state->pending.config mtk_crtc->pending_async_planes plane_state->pending.async_config
These configuration flags may be set to false when a GCE IRQ comes calling ddp_cmdq_cb(). This may result in missing prepare instructions, especially if mtk_crtc_update_config() with the flase need_vblank (no need to wait for vblank) cases.
Therefore, the mtk_crtc->config_updating flag is set at the beginning of mtk_crtc_update_config() to ensure that these configuration flags won't be changed when the mtk_crtc_ddp_config() is preparing instructions. But somehow the ddp_cmdq_cb() didn't use the mtk_crtc->config_updating flag to prevent those pending config flags from being cleared.
To avoid missing the configuration when generating the config instruction, the config_updating flag should be added into ddp_cmdq_cb() and be protected with spin_lock.
Fixes: 7f82d9c43879 ("drm/mediatek: Clear pending flag when cmdq packet is done") Signed-off-by: Jason-JH.Lin jason-jh.lin@mediatek.com Reviewed-by: CK Hu ck.hu@mediatek.com Reviewed-by: Fei Shao fshao@chromium.org Link: https://patchwork.kernel.org/project/dri-devel/patch/20240827-drm-fixup-0819... Link: https://patchwork.kernel.org/project/dri-devel/patch/20240827-drm-fixup-0819... Signed-off-by: Chun-Kuang Hu chunkuang.hu@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 27 +++++++++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c index 29e021ec6901c..5a1c8b26f1bb1 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c @@ -67,6 +67,8 @@ struct mtk_drm_crtc { /* lock for display hardware access */ struct mutex hw_lock; bool config_updating; + /* lock for config_updating to cmd buffer */ + spinlock_t config_lock; };
struct mtk_crtc_state { @@ -104,11 +106,16 @@ static void mtk_drm_crtc_finish_page_flip(struct mtk_drm_crtc *mtk_crtc)
static void mtk_drm_finish_page_flip(struct mtk_drm_crtc *mtk_crtc) { + unsigned long flags; + drm_crtc_handle_vblank(&mtk_crtc->base); + + spin_lock_irqsave(&mtk_crtc->config_lock, flags); if (!mtk_crtc->config_updating && mtk_crtc->pending_needs_vblank) { mtk_drm_crtc_finish_page_flip(mtk_crtc); mtk_crtc->pending_needs_vblank = false; } + spin_unlock_irqrestore(&mtk_crtc->config_lock, flags); }
#if IS_REACHABLE(CONFIG_MTK_CMDQ) @@ -291,12 +298,19 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg) struct mtk_drm_crtc *mtk_crtc = container_of(cmdq_cl, struct mtk_drm_crtc, cmdq_client); struct mtk_crtc_state *state; unsigned int i; + unsigned long flags;
if (data->sta < 0) return;
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); + goto ddp_cmdq_cb_out; + } + state->pending_config = false;
if (mtk_crtc->pending_planes) { @@ -323,6 +337,10 @@ 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: + mtk_crtc->cmdq_vblank_cnt = 0; wake_up(&mtk_crtc->cb_blocking_queue); } @@ -555,9 +573,14 @@ static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc, struct mtk_drm_private *priv = crtc->dev->dev_private; unsigned int pending_planes = 0, pending_async_planes = 0; int i; + unsigned long flags;
mutex_lock(&mtk_crtc->hw_lock); + + spin_lock_irqsave(&mtk_crtc->config_lock, flags); mtk_crtc->config_updating = true; + spin_unlock_irqrestore(&mtk_crtc->config_lock, flags); + if (needs_vblank) mtk_crtc->pending_needs_vblank = true;
@@ -611,7 +634,10 @@ static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc, 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); }
@@ -1014,6 +1040,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev, drm_mode_crtc_set_gamma_size(&mtk_crtc->base, gamma_lut_size); drm_crtc_enable_color_mgmt(&mtk_crtc->base, 0, has_ctm, gamma_lut_size); mutex_init(&mtk_crtc->hw_lock); + spin_lock_init(&mtk_crtc->config_lock);
#if IS_REACHABLE(CONFIG_MTK_CMDQ) i = priv->mbox_index++;