[PATCH 0/4] CMDQ refinement of Mediatek DRM driver

[PATCH 0/4] CMDQ refinement of Mediatek DRM driver

[Chun-Kuang Hu]

These refinements include using standard mailbox callback interface,
timeout detection, and a fixed cmdq_handle.

Chun-Kuang Hu (4):
  drm/mediatek: Use mailbox rx_callback instead of cmdq_task_cb
  drm/mediatek: Remove struct cmdq_client
  drm/mediatek: Detect CMDQ execution timeout
  drm/mediatek: Add cmdq_handle in mtk_crtc

 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 110 ++++++++++++++++++++----
 1 file changed, 91 insertions(+), 19 deletions(-)

-- 
2.25.1

[PATCH 1/4] drm/mediatek: Use mailbox rx_callback instead of cmdq_task_cb

[Chun-Kuang Hu]

rx_callback is a standard mailbox callback mechanism and could cover the
function of proprietary cmdq_task_cb, so use the standard one instead of
the proprietary one.

Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 474efb844249..cac8fe219c95 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -4,6 +4,8 @@
  */
 
 #include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/mailbox_controller.h>
 #include <linux/pm_runtime.h>
 #include <linux/soc/mediatek/mtk-cmdq.h>
 #include <linux/soc/mediatek/mtk-mmsys.h>
@@ -222,9 +224,11 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
 }
 
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
-static void ddp_cmdq_cb(struct cmdq_cb_data data)
+static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
 {
-	cmdq_pkt_destroy(data.data);
+	struct cmdq_cb_data *data = mssg;
+
+	cmdq_pkt_destroy(data->pkt);
 }
 #endif
 
@@ -475,7 +479,12 @@ static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc,
 		cmdq_pkt_wfe(cmdq_handle, mtk_crtc->cmdq_event, false);
 		mtk_crtc_ddp_config(crtc, cmdq_handle);
 		cmdq_pkt_finalize(cmdq_handle);
-		cmdq_pkt_flush_async(cmdq_handle, ddp_cmdq_cb, cmdq_handle);
+		dma_sync_single_for_device(mtk_crtc->cmdq_client->chan->mbox->dev,
+					    cmdq_handle->pa_base,
+					    cmdq_handle->cmd_buf_size,
+					    DMA_TO_DEVICE);
+		mbox_send_message(mtk_crtc->cmdq_client->chan, cmdq_handle);
+		mbox_client_txdone(mtk_crtc->cmdq_client->chan, 0);
 	}
 #endif
 	mtk_crtc->config_updating = false;
@@ -842,6 +851,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 	}
 
 	if (mtk_crtc->cmdq_client) {
+		mtk_crtc->cmdq_client->client.rx_callback = ddp_cmdq_cb;
 		ret = of_property_read_u32_index(priv->mutex_node,
 						 "mediatek,gce-events",
 						 drm_crtc_index(&mtk_crtc->base),
-- 
2.25.1

[PATCH 2/4] drm/mediatek: Remove struct cmdq_client

[Chun-Kuang Hu]

In mailbox rx_callback, it pass struct mbox_client to callback
function, but it could not map back to mtk_drm_crtc instance
because struct cmdq_client use a pointer to struct mbox_client:

struct cmdq_client {
	struct mbox_client client;
	struct mbox_chan *chan;
};

struct mtk_drm_crtc {
	/* client instance data */
	struct cmdq_client *cmdq_client;
};

so remove struct cmdq_client and let mtk_drm_crtc instance define
mbox_client as:

struct mtk_drm_crtc {
	/* client instance data */
	struct mbox_client cl;
};

and in rx_callback function, use struct mbox_client to get
struct mtk_drm_crtc.

Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 80 +++++++++++++++++++------
 1 file changed, 62 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index cac8fe219c95..db8621df7d85 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -52,7 +52,8 @@ struct mtk_drm_crtc {
 	bool				pending_async_planes;
 
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
-	struct cmdq_client		*cmdq_client;
+	struct mbox_client		cmdq_cl;
+	struct mbox_chan		*cmdq_chan;
 	u32				cmdq_event;
 #endif
 
@@ -223,12 +224,52 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
 	return NULL;
 }
 
+static struct cmdq_pkt *mtk_drm_cmdq_pkt_create(struct mbox_chan *chan, size_t size)
+{
+	struct cmdq_pkt *pkt;
+	struct device *dev;
+	dma_addr_t dma_addr;
+
+	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+	if (!pkt)
+		return ERR_PTR(-ENOMEM);
+	pkt->va_base = kzalloc(size, GFP_KERNEL);
+	if (!pkt->va_base) {
+		kfree(pkt);
+		return ERR_PTR(-ENOMEM);
+	}
+	pkt->buf_size = size;
+
+	dev = chan->mbox->dev;
+	dma_addr = dma_map_single(dev, pkt->va_base, pkt->buf_size,
+				  DMA_TO_DEVICE);
+	if (dma_mapping_error(dev, dma_addr)) {
+		dev_err(dev, "dma map failed, size=%u\n", (u32)(u64)size);
+		kfree(pkt->va_base);
+		kfree(pkt);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	pkt->pa_base = dma_addr;
+
+	return pkt;
+}
+
+static void mtk_drm_cmdq_pkt_destroy(struct mbox_chan *chan, struct cmdq_pkt *pkt)
+{
+	dma_unmap_single(chan->mbox->dev, pkt->pa_base, pkt->buf_size,
+			 DMA_TO_DEVICE);
+	kfree(pkt->va_base);
+	kfree(pkt);
+}
+
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
 static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
 {
+	struct mtk_drm_crtc *mtk_crtc = container_of(cl, struct mtk_drm_crtc, cmdq_cl);
 	struct cmdq_cb_data *data = mssg;
 
-	cmdq_pkt_destroy(data->pkt);
+	mtk_drm_cmdq_pkt_destroy(mtk_crtc->cmdq_chan, data->pkt);
 }
 #endif
 
@@ -472,19 +513,19 @@ static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc,
 		mtk_mutex_release(mtk_crtc->mutex);
 	}
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
-	if (mtk_crtc->cmdq_client) {
-		mbox_flush(mtk_crtc->cmdq_client->chan, 2000);
-		cmdq_handle = cmdq_pkt_create(mtk_crtc->cmdq_client, PAGE_SIZE);
+	if (mtk_crtc->cmdq_chan) {
+		mbox_flush(mtk_crtc->cmdq_chan, 2000);
+		cmdq_handle = mtk_drm_cmdq_pkt_create(mtk_crtc->cmdq_chan, PAGE_SIZE);
 		cmdq_pkt_clear_event(cmdq_handle, mtk_crtc->cmdq_event);
 		cmdq_pkt_wfe(cmdq_handle, mtk_crtc->cmdq_event, false);
 		mtk_crtc_ddp_config(crtc, cmdq_handle);
 		cmdq_pkt_finalize(cmdq_handle);
-		dma_sync_single_for_device(mtk_crtc->cmdq_client->chan->mbox->dev,
+		dma_sync_single_for_device(mtk_crtc->cmdq_chan->mbox->dev,
 					    cmdq_handle->pa_base,
 					    cmdq_handle->cmd_buf_size,
 					    DMA_TO_DEVICE);
-		mbox_send_message(mtk_crtc->cmdq_client->chan, cmdq_handle);
-		mbox_client_txdone(mtk_crtc->cmdq_client->chan, 0);
+		mbox_send_message(mtk_crtc->cmdq_chan, cmdq_handle);
+		mbox_client_txdone(mtk_crtc->cmdq_chan, 0);
 	}
 #endif
 	mtk_crtc->config_updating = false;
@@ -498,7 +539,7 @@ static void mtk_crtc_ddp_irq(void *data)
 	struct mtk_drm_private *priv = crtc->dev->dev_private;
 
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
-	if (!priv->data->shadow_register && !mtk_crtc->cmdq_client)
+	if (!priv->data->shadow_register && !mtk_crtc->cmdq_chan)
 #else
 	if (!priv->data->shadow_register)
 #endif
@@ -841,17 +882,20 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 	mutex_init(&mtk_crtc->hw_lock);
 
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
-	mtk_crtc->cmdq_client =
-			cmdq_mbox_create(mtk_crtc->mmsys_dev,
-					 drm_crtc_index(&mtk_crtc->base));
-	if (IS_ERR(mtk_crtc->cmdq_client)) {
+	mtk_crtc->cmdq_cl.dev = mtk_crtc->mmsys_dev;
+	mtk_crtc->cmdq_cl.tx_block = false;
+	mtk_crtc->cmdq_cl.knows_txdone = true;
+	mtk_crtc->cmdq_cl.rx_callback = ddp_cmdq_cb;
+	mtk_crtc->cmdq_chan =
+			mbox_request_channel(&mtk_crtc->cmdq_cl,
+					      drm_crtc_index(&mtk_crtc->base));
+	if (IS_ERR(mtk_crtc->cmdq_chan)) {
 		dev_dbg(dev, "mtk_crtc %d failed to create mailbox client, writing register by CPU now\n",
 			drm_crtc_index(&mtk_crtc->base));
-		mtk_crtc->cmdq_client = NULL;
+		mtk_crtc->cmdq_chan = NULL;
 	}
 
-	if (mtk_crtc->cmdq_client) {
-		mtk_crtc->cmdq_client->client.rx_callback = ddp_cmdq_cb;
+	if (mtk_crtc->cmdq_chan) {
 		ret = of_property_read_u32_index(priv->mutex_node,
 						 "mediatek,gce-events",
 						 drm_crtc_index(&mtk_crtc->base),
@@ -859,8 +903,8 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 		if (ret) {
 			dev_dbg(dev, "mtk_crtc %d failed to get mediatek,gce-events property\n",
 				drm_crtc_index(&mtk_crtc->base));
-			cmdq_mbox_destroy(mtk_crtc->cmdq_client);
-			mtk_crtc->cmdq_client = NULL;
+			mbox_free_channel(mtk_crtc->cmdq_chan);
+			mtk_crtc->cmdq_chan = NULL;
 		}
 	}
 #endif
-- 
2.25.1

[PATCH 3/4] drm/mediatek: Detect CMDQ execution timeout

[Chun-Kuang Hu]

CMDQ is used to update display register in vblank period, so
it should be execute in next vblank. If it fail to execute
in next 2 vblank, tiemout happen.

Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index db8621df7d85..5dd61eacce6c 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -55,6 +55,7 @@ struct mtk_drm_crtc {
 	struct mbox_client		cmdq_cl;
 	struct mbox_chan		*cmdq_chan;
 	u32				cmdq_event;
+	u32				cmdq_vblank_cnt;
 #endif
 
 	struct device			*mmsys_dev;
@@ -269,6 +270,7 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
 	struct mtk_drm_crtc *mtk_crtc = container_of(cl, struct mtk_drm_crtc, cmdq_cl);
 	struct cmdq_cb_data *data = mssg;
 
+	mtk_crtc->cmdq_vblank_cnt = 0;
 	mtk_drm_cmdq_pkt_destroy(mtk_crtc->cmdq_chan, data->pkt);
 }
 #endif
@@ -524,6 +526,11 @@ static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc,
 					    cmdq_handle->pa_base,
 					    cmdq_handle->cmd_buf_size,
 					    DMA_TO_DEVICE);
+		/*
+		 * CMDQ command should execute in next vblank,
+		 * If it fail to execute in next 2 vblank, timeout happen.
+		 */
+		mtk_crtc->cmdq_vblank_cnt = 2;
 		mbox_send_message(mtk_crtc->cmdq_chan, cmdq_handle);
 		mbox_client_txdone(mtk_crtc->cmdq_chan, 0);
 	}
@@ -540,11 +547,14 @@ static void mtk_crtc_ddp_irq(void *data)
 
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
 	if (!priv->data->shadow_register && !mtk_crtc->cmdq_chan)
+		mtk_crtc_ddp_config(crtc, NULL);
+	else if (mtk_crtc->cmdq_vblank_cnt > 0 && --mtk_crtc->cmdq_vblank_cnt == 0)
+		DRM_ERROR("mtk_crtc %d CMDQ execute command timeout!\n",
+			  drm_crtc_index(&mtk_crtc->base));
 #else
 	if (!priv->data->shadow_register)
-#endif
 		mtk_crtc_ddp_config(crtc, NULL);
-
+#endif
 	mtk_drm_finish_page_flip(mtk_crtc);
 }
 
-- 
2.25.1

[PATCH 4/4] drm/mediatek: Add cmdq_handle in mtk_crtc

[Chun-Kuang Hu]

One mtk_crtc need just one cmdq_handle, so add one cmdq_handle
in mtk_crtc to prevent frequently allocation and free of
cmdq_handle.

Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 28 ++++++++++++++++---------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 5dd61eacce6c..4c25e33638a7 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -54,6 +54,7 @@ struct mtk_drm_crtc {
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
 	struct mbox_client		cmdq_cl;
 	struct mbox_chan		*cmdq_chan;
+	struct cmdq_pkt			cmdq_handle;
 	u32				cmdq_event;
 	u32				cmdq_vblank_cnt;
 #endif
@@ -225,19 +226,16 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
 	return NULL;
 }
 
-static struct cmdq_pkt *mtk_drm_cmdq_pkt_create(struct mbox_chan *chan, size_t size)
+static int mtk_drm_cmdq_pkt_create(struct mbox_chan *chan, struct cmdq_pkt *pkt,
+				    size_t size)
 {
-	struct cmdq_pkt *pkt;
 	struct device *dev;
 	dma_addr_t dma_addr;
 
-	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
-	if (!pkt)
-		return ERR_PTR(-ENOMEM);
 	pkt->va_base = kzalloc(size, GFP_KERNEL);
 	if (!pkt->va_base) {
 		kfree(pkt);
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 	}
 	pkt->buf_size = size;
 
@@ -248,12 +246,12 @@ static struct cmdq_pkt *mtk_drm_cmdq_pkt_create(struct mbox_chan *chan, size_t s
 		dev_err(dev, "dma map failed, size=%u\n", (u32)(u64)size);
 		kfree(pkt->va_base);
 		kfree(pkt);
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 	}
 
 	pkt->pa_base = dma_addr;
 
-	return pkt;
+	return 0;
 }
 
 static void mtk_drm_cmdq_pkt_destroy(struct mbox_chan *chan, struct cmdq_pkt *pkt)
@@ -477,7 +475,7 @@ static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc,
 				       bool needs_vblank)
 {
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
-	struct cmdq_pkt *cmdq_handle;
+	struct cmdq_pkt *cmdq_handle = &mtk_crtc->cmdq_handle;
 #endif
 	struct drm_crtc *crtc = &mtk_crtc->base;
 	struct mtk_drm_private *priv = crtc->dev->dev_private;
@@ -517,7 +515,7 @@ static void mtk_drm_crtc_update_config(struct mtk_drm_crtc *mtk_crtc,
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
 	if (mtk_crtc->cmdq_chan) {
 		mbox_flush(mtk_crtc->cmdq_chan, 2000);
-		cmdq_handle = mtk_drm_cmdq_pkt_create(mtk_crtc->cmdq_chan, PAGE_SIZE);
+		cmdq_handle->cmd_buf_size = 0;
 		cmdq_pkt_clear_event(cmdq_handle, mtk_crtc->cmdq_event);
 		cmdq_pkt_wfe(cmdq_handle, mtk_crtc->cmdq_event, false);
 		mtk_crtc_ddp_config(crtc, cmdq_handle);
@@ -915,6 +913,16 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 				drm_crtc_index(&mtk_crtc->base));
 			mbox_free_channel(mtk_crtc->cmdq_chan);
 			mtk_crtc->cmdq_chan = NULL;
+		} else {
+			ret = mtk_drm_cmdq_pkt_create(mtk_crtc->cmdq_chan,
+						       &mtk_crtc->cmdq_handle,
+						       PAGE_SIZE);
+			if (ret) {
+				dev_dbg(dev, "mtk_crtc %d failed to create cmdq packet\n",
+					drm_crtc_index(&mtk_crtc->base));
+				mbox_free_channel(mtk_crtc->cmdq_chan);
+				mtk_crtc->cmdq_chan = NULL;
+			}
 		}
 	}
 #endif
-- 
2.25.1