[PATCH v2 0/4] CMDQ refinement of Mediatek DRM driver

[PATCH v2 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.

Changes in v2:
1. Define mtk_drm_cmdq_pkt_create() and mtk_drm_cmdq_pkt_destroy()
   when CONFIG_MTK_CMDQ is reachable.

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


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[PATCH v2 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


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[PATCH v2 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..da92a3fedd0a 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
 
@@ -224,11 +225,51 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
 }
 
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
+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);
+}
+
 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


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[PATCH v2 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 da92a3fedd0a..ad4c1a3a9294 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


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[PATCH v2 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 ad4c1a3a9294..2d9becec04a9 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
@@ -226,19 +227,16 @@ struct mtk_ddp_comp *mtk_drm_ddp_comp_for_plane(struct drm_crtc *crtc,
 }
 
 #if IS_REACHABLE(CONFIG_MTK_CMDQ)
-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;
 
@@ -249,12 +247,12 @@ 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


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Re: [PATCH v2 0/4] CMDQ refinement of Mediatek DRM driver

[Chun-Kuang Hu]

Chun-Kuang Hu <chunkuang.hu@kernel.org> 於 2021年8月9日 週一 上午7:47寫道：
>
> These refinements include using standard mailbox callback interface,
> timeout detection, and a fixed cmdq_handle.

For this series, applied to mediatek-drm-next [1].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next

Regards,
Chun-Kuang.

>
> Changes in v2:
> 1. Define mtk_drm_cmdq_pkt_create() and mtk_drm_cmdq_pkt_destroy()
>    when CONFIG_MTK_CMDQ is reachable.
>
> 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
>

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Re: [PATCH v2 0/4] CMDQ refinement of Mediatek DRM driver

[Enric Balletbo Serra]

Hi Chun-Kuang,

(again without html format, sorry for the noise)

Missatge de Chun-Kuang Hu <chunkuang.hu@kernel.org> del dia dj., 12
d’ag. 2021 a les 2:13:
>
> Chun-Kuang Hu <chunkuang.hu@kernel.org> 於 2021年8月9日 週一 上午7:47寫道：
> >
> > These refinements include using standard mailbox callback interface,
> > timeout detection, and a fixed cmdq_handle.
>
> For this series, applied to mediatek-drm-next [1].
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next
>

These patches seem to break the display on the Acer Chromebook R 13
(MT8173) in the current mainline. After running a bisection it pointed
me to the following commit

commit f4be17cd5b14dd73545b0e014a63ebe9ab5ef837
Author: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date:   Sun Jul 4 15:36:48 2021 +0800

    drm/mediatek: Remove struct cmdq_client

Reverting this patch alone is not trivial, so I ended up reverting the
full series, and I can confirm that reverting the full series makes
the display work again.

Unfortunately, after the merge window, different things broke for this
device, and I didn't finish isolating them, and it is not clear to me
yet whether the logs I'm getting are useful for this specific issue or
not. Basically with this series merged the kernel seems to be stuck,
and the display is not working. Latest message is

[   12.329173] mtk-iommu 10205000.iommu: Partial TLB flush timed out,
falling back to full flush

Without the series, the kernel goes far and display works, however
there are other issues affecting the cros-ec, but I think that's
another issue.

I'll try to dig a bit more, but, meanwhile, if you have any idea
please let me know.

Thanks,
 Enric


> Regards,
> Chun-Kuang.
>
> >
> > Changes in v2:
> > 1. Define mtk_drm_cmdq_pkt_create() and mtk_drm_cmdq_pkt_destroy()
> >    when CONFIG_MTK_CMDQ is reachable.
> >
> > 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
> >

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Re: [PATCH v2 0/4] CMDQ refinement of Mediatek DRM driver

[Chun-Kuang Hu]

Hi, Enric:

Enric Balletbo Serra <eballetbo@gmail.com> 於 2021年9月21日 週二 下午4:36寫道：
>
> Hi Chun-Kuang,
>
> (again without html format, sorry for the noise)
>
> Missatge de Chun-Kuang Hu <chunkuang.hu@kernel.org> del dia dj., 12
> d’ag. 2021 a les 2:13:
> >
> > Chun-Kuang Hu <chunkuang.hu@kernel.org> 於 2021年8月9日 週一 上午7:47寫道：
> > >
> > > These refinements include using standard mailbox callback interface,
> > > timeout detection, and a fixed cmdq_handle.
> >
> > For this series, applied to mediatek-drm-next [1].
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next
> >
>
> These patches seem to break the display on the Acer Chromebook R 13
> (MT8173) in the current mainline. After running a bisection it pointed
> me to the following commit
>
> commit f4be17cd5b14dd73545b0e014a63ebe9ab5ef837
> Author: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> Date:   Sun Jul 4 15:36:48 2021 +0800
>
>     drm/mediatek: Remove struct cmdq_client
>
> Reverting this patch alone is not trivial, so I ended up reverting the
> full series, and I can confirm that reverting the full series makes
> the display work again.

I think you could not just revert "drm/mediatek: Remove struct
cmdq_client", you should also revert the patches after it, such as

"drm/mediatek: Clear pending flag when cmdq packet is done"
"drm/mediatek: Add cmdq_handle in mtk_crtc"
"drm/mediatek: Detect CMDQ execution timeout"

If "drm/mediatek: Remove struct cmdq_client" is the patch cause
display abnormal, I think you could compare code w/ and w/o this
patch. Focus on the value accuracy, such as cmdq_cl and cmdq_chan. And
focus on the flow accuracy, such as mtk_drm_crtc_update_config() and
ddp_cmdq_cb(). If this could not find the problem, I think the latest
way is to break this patch into small patches, changes little in each
small patches and we could finally find out the problem.

Regards,
Chun-Kuang.

>
> Unfortunately, after the merge window, different things broke for this
> device, and I didn't finish isolating them, and it is not clear to me
> yet whether the logs I'm getting are useful for this specific issue or
> not. Basically with this series merged the kernel seems to be stuck,
> and the display is not working. Latest message is
>
> [   12.329173] mtk-iommu 10205000.iommu: Partial TLB flush timed out,
> falling back to full flush
>
> Without the series, the kernel goes far and display works, however
> there are other issues affecting the cros-ec, but I think that's
> another issue.
>
> I'll try to dig a bit more, but, meanwhile, if you have any idea
> please let me know.
>
> Thanks,
>  Enric
>
>
> > Regards,
> > Chun-Kuang.
> >
> > >
> > > Changes in v2:
> > > 1. Define mtk_drm_cmdq_pkt_create() and mtk_drm_cmdq_pkt_destroy()
> > >    when CONFIG_MTK_CMDQ is reachable.
> > >
> > > 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
> > >

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Re: [PATCH v2 0/4] CMDQ refinement of Mediatek DRM driver

[Enric Balletbo Serra]

Hi Chun-Kuang,

Missatge de Chun-Kuang Hu <chunkuang.hu@kernel.org> del dia dt., 21 de
set. 2021 a les 15:15:
>
> Hi, Enric:
>
> Enric Balletbo Serra <eballetbo@gmail.com> 於 2021年9月21日 週二 下午4:36寫道：
> >
> > Hi Chun-Kuang,
> >
> > (again without html format, sorry for the noise)
> >
> > Missatge de Chun-Kuang Hu <chunkuang.hu@kernel.org> del dia dj., 12
> > d’ag. 2021 a les 2:13:
> > >
> > > Chun-Kuang Hu <chunkuang.hu@kernel.org> 於 2021年8月9日 週一 上午7:47寫道：
> > > >
> > > > These refinements include using standard mailbox callback interface,
> > > > timeout detection, and a fixed cmdq_handle.
> > >
> > > For this series, applied to mediatek-drm-next [1].
> > >
> > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next
> > >
> >
> > These patches seem to break the display on the Acer Chromebook R 13
> > (MT8173) in the current mainline. After running a bisection it pointed
> > me to the following commit
> >
> > commit f4be17cd5b14dd73545b0e014a63ebe9ab5ef837
> > Author: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> > Date:   Sun Jul 4 15:36:48 2021 +0800
> >
> >     drm/mediatek: Remove struct cmdq_client
> >
> > Reverting this patch alone is not trivial, so I ended up reverting the
> > full series, and I can confirm that reverting the full series makes
> > the display work again.
>
> I think you could not just revert "drm/mediatek: Remove struct
> cmdq_client", you should also revert the patches after it, such as
>
> "drm/mediatek: Clear pending flag when cmdq packet is done"
> "drm/mediatek: Add cmdq_handle in mtk_crtc"
> "drm/mediatek: Detect CMDQ execution timeout"
>

Yes, in fact I reverted:

9efb16c2fdd6 drm/mediatek: Clear pending flag when cmdq packet is done
bc9241be73d9 drm/mediatek: Add cmdq_handle in mtk_crtc
8cdcb3653424 drm/mediatek: Detect CMDQ execution timeout
f4be17cd5b14 drm/mediatek: Remove struct cmdq_client
c1ec54b7b5af drm/mediatek: Use mailbox rx_callback instead of cmdq_task_cb

Without these patches 5.15-rc2 works again on my platform.

The commit 'c1ec54b7b5af drm/mediatek: Use mailbox rx_callback instead
of cmdq_task_cb' alone introduces lots of warnings in the kernel

WARNING: CPU: 0 PID: 0 at drivers/mailbox/mtk-cmdq-mailbox.c:198
cmdq_task_exec_done+0xb8/0xe0

I think is just a leftover or the mentioned warning, but that confused
me a bit doing the bisection. Then, after commit 'f4be17cd5b14
drm/mediatek: Remove struct cmdq_client' my system simply gets stuck.
For now I don't see any obvious mistake but will dig further.

Can I ask you in which platform did you test? And if you can double
check if your platform is broken too in current mainline?

Thanks,
  Enric

> If "drm/mediatek: Remove struct cmdq_client" is the patch cause
> display abnormal, I think you could compare code w/ and w/o this
> patch. Focus on the value accuracy, such as cmdq_cl and cmdq_chan. And
> focus on the flow accuracy, such as mtk_drm_crtc_update_config() and
> ddp_cmdq_cb(). If this could not find the problem, I think the latest
> way is to break this patch into small patches, changes little in each
> small patches and we could finally find out the problem.
>
> Regards,
> Chun-Kuang.
>
> >
> > Unfortunately, after the merge window, different things broke for this
> > device, and I didn't finish isolating them, and it is not clear to me
> > yet whether the logs I'm getting are useful for this specific issue or
> > not. Basically with this series merged the kernel seems to be stuck,
> > and the display is not working. Latest message is
> >
> > [   12.329173] mtk-iommu 10205000.iommu: Partial TLB flush timed out,
> > falling back to full flush
> >
> > Without the series, the kernel goes far and display works, however
> > there are other issues affecting the cros-ec, but I think that's
> > another issue.
> >
> > I'll try to dig a bit more, but, meanwhile, if you have any idea
> > please let me know.
> >
> > Thanks,
> >  Enric
> >
> >
> > > Regards,
> > > Chun-Kuang.
> > >
> > > >
> > > > Changes in v2:
> > > > 1. Define mtk_drm_cmdq_pkt_create() and mtk_drm_cmdq_pkt_destroy()
> > > >    when CONFIG_MTK_CMDQ is reachable.
> > > >
> > > > 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
> > > >

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Re: [PATCH v2 0/4] CMDQ refinement of Mediatek DRM driver

[Chun-Kuang Hu]

Hi, Enric:

Enric Balletbo Serra <eballetbo@gmail.com> 於 2021年9月24日 週五 上午12:36寫道：
>
> Hi Chun-Kuang,
>
> Missatge de Chun-Kuang Hu <chunkuang.hu@kernel.org> del dia dt., 21 de
> set. 2021 a les 15:15:
> >
> > Hi, Enric:
> >
> > Enric Balletbo Serra <eballetbo@gmail.com> 於 2021年9月21日 週二 下午4:36寫道：
> > >
> > > Hi Chun-Kuang,
> > >
> > > (again without html format, sorry for the noise)
> > >
> > > Missatge de Chun-Kuang Hu <chunkuang.hu@kernel.org> del dia dj., 12
> > > d’ag. 2021 a les 2:13:
> > > >
> > > > Chun-Kuang Hu <chunkuang.hu@kernel.org> 於 2021年8月9日 週一 上午7:47寫道：
> > > > >
> > > > > These refinements include using standard mailbox callback interface,
> > > > > timeout detection, and a fixed cmdq_handle.
> > > >
> > > > For this series, applied to mediatek-drm-next [1].
> > > >
> > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next
> > > >
> > >
> > > These patches seem to break the display on the Acer Chromebook R 13
> > > (MT8173) in the current mainline. After running a bisection it pointed
> > > me to the following commit
> > >
> > > commit f4be17cd5b14dd73545b0e014a63ebe9ab5ef837
> > > Author: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> > > Date:   Sun Jul 4 15:36:48 2021 +0800
> > >
> > >     drm/mediatek: Remove struct cmdq_client
> > >
> > > Reverting this patch alone is not trivial, so I ended up reverting the
> > > full series, and I can confirm that reverting the full series makes
> > > the display work again.
> >
> > I think you could not just revert "drm/mediatek: Remove struct
> > cmdq_client", you should also revert the patches after it, such as
> >
> > "drm/mediatek: Clear pending flag when cmdq packet is done"
> > "drm/mediatek: Add cmdq_handle in mtk_crtc"
> > "drm/mediatek: Detect CMDQ execution timeout"
> >
>
> Yes, in fact I reverted:
>
> 9efb16c2fdd6 drm/mediatek: Clear pending flag when cmdq packet is done
> bc9241be73d9 drm/mediatek: Add cmdq_handle in mtk_crtc
> 8cdcb3653424 drm/mediatek: Detect CMDQ execution timeout
> f4be17cd5b14 drm/mediatek: Remove struct cmdq_client
> c1ec54b7b5af drm/mediatek: Use mailbox rx_callback instead of cmdq_task_cb
>
> Without these patches 5.15-rc2 works again on my platform.
>
> The commit 'c1ec54b7b5af drm/mediatek: Use mailbox rx_callback instead
> of cmdq_task_cb' alone introduces lots of warnings in the kernel
>
> WARNING: CPU: 0 PID: 0 at drivers/mailbox/mtk-cmdq-mailbox.c:198
> cmdq_task_exec_done+0xb8/0xe0

I think the WARN_ON in cmdq driver should be remove because that
warning show that cmdq_task_cb is not used but I that is what I want.

>
> I think is just a leftover or the mentioned warning, but that confused
> me a bit doing the bisection. Then, after commit 'f4be17cd5b14
> drm/mediatek: Remove struct cmdq_client' my system simply gets stuck.
> For now I don't see any obvious mistake but will dig further.
>
> Can I ask you in which platform did you test? And if you can double
> check if your platform is broken too in current mainline?

I've no environment to test code now. I apply this series because I
assume Yongqiang has test his patch "Clear pending flag when cmdq
packet is done".  Before I setup the environment (this may take a long
time), I would find others to fix this problem.
According to your information, "c1ec54b7b5af drm/mediatek: Use mailbox
rx_callback instead of cmdq_task_cb" would cause many warning but
display still work, right? If so, I think we should focus on
"f4be17cd5b14 drm/mediatek: Remove struct cmdq_client".

Regards,
Chun-Kuang.

>
> Thanks,
>   Enric
>
> > If "drm/mediatek: Remove struct cmdq_client" is the patch cause
> > display abnormal, I think you could compare code w/ and w/o this
> > patch. Focus on the value accuracy, such as cmdq_cl and cmdq_chan. And
> > focus on the flow accuracy, such as mtk_drm_crtc_update_config() and
> > ddp_cmdq_cb(). If this could not find the problem, I think the latest
> > way is to break this patch into small patches, changes little in each
> > small patches and we could finally find out the problem.
> >
> > Regards,
> > Chun-Kuang.
> >
> > >
> > > Unfortunately, after the merge window, different things broke for this
> > > device, and I didn't finish isolating them, and it is not clear to me
> > > yet whether the logs I'm getting are useful for this specific issue or
> > > not. Basically with this series merged the kernel seems to be stuck,
> > > and the display is not working. Latest message is
> > >
> > > [   12.329173] mtk-iommu 10205000.iommu: Partial TLB flush timed out,
> > > falling back to full flush
> > >
> > > Without the series, the kernel goes far and display works, however
> > > there are other issues affecting the cros-ec, but I think that's
> > > another issue.
> > >
> > > I'll try to dig a bit more, but, meanwhile, if you have any idea
> > > please let me know.
> > >
> > > Thanks,
> > >  Enric
> > >
> > >
> > > > Regards,
> > > > Chun-Kuang.
> > > >
> > > > >
> > > > > Changes in v2:
> > > > > 1. Define mtk_drm_cmdq_pkt_create() and mtk_drm_cmdq_pkt_destroy()
> > > > >    when CONFIG_MTK_CMDQ is reachable.
> > > > >
> > > > > 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
> > > > >

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Re: [PATCH v2 0/4] CMDQ refinement of Mediatek DRM driver

[Chun-Kuang Hu]

+Jason:

Hi, Enric:

Please test Jason's series [1], [2]. Does these series fixes your problem?

[1] https://patchwork.kernel.org/project/linux-mediatek/list/?series=554759
[2] https://patchwork.kernel.org/project/linux-mediatek/list/?series=554767

Regards,
Chun-Kuang.

Chun-Kuang Hu <chunkuang.hu@kernel.org> 於 2021年9月24日 週五 上午7:43寫道：
>
> Hi, Enric:
>
> Enric Balletbo Serra <eballetbo@gmail.com> 於 2021年9月24日 週五 上午12:36寫道：
> >
> > Hi Chun-Kuang,
> >
> > Missatge de Chun-Kuang Hu <chunkuang.hu@kernel.org> del dia dt., 21 de
> > set. 2021 a les 15:15:
> > >
> > > Hi, Enric:
> > >
> > > Enric Balletbo Serra <eballetbo@gmail.com> 於 2021年9月21日 週二 下午4:36寫道：
> > > >
> > > > Hi Chun-Kuang,
> > > >
> > > > (again without html format, sorry for the noise)
> > > >
> > > > Missatge de Chun-Kuang Hu <chunkuang.hu@kernel.org> del dia dj., 12
> > > > d’ag. 2021 a les 2:13:
> > > > >
> > > > > Chun-Kuang Hu <chunkuang.hu@kernel.org> 於 2021年8月9日 週一 上午7:47寫道：
> > > > > >
> > > > > > These refinements include using standard mailbox callback interface,
> > > > > > timeout detection, and a fixed cmdq_handle.
> > > > >
> > > > > For this series, applied to mediatek-drm-next [1].
> > > > >
> > > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next
> > > > >
> > > >
> > > > These patches seem to break the display on the Acer Chromebook R 13
> > > > (MT8173) in the current mainline. After running a bisection it pointed
> > > > me to the following commit
> > > >
> > > > commit f4be17cd5b14dd73545b0e014a63ebe9ab5ef837
> > > > Author: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> > > > Date:   Sun Jul 4 15:36:48 2021 +0800
> > > >
> > > >     drm/mediatek: Remove struct cmdq_client
> > > >
> > > > Reverting this patch alone is not trivial, so I ended up reverting the
> > > > full series, and I can confirm that reverting the full series makes
> > > > the display work again.
> > >
> > > I think you could not just revert "drm/mediatek: Remove struct
> > > cmdq_client", you should also revert the patches after it, such as
> > >
> > > "drm/mediatek: Clear pending flag when cmdq packet is done"
> > > "drm/mediatek: Add cmdq_handle in mtk_crtc"
> > > "drm/mediatek: Detect CMDQ execution timeout"
> > >
> >
> > Yes, in fact I reverted:
> >
> > 9efb16c2fdd6 drm/mediatek: Clear pending flag when cmdq packet is done
> > bc9241be73d9 drm/mediatek: Add cmdq_handle in mtk_crtc
> > 8cdcb3653424 drm/mediatek: Detect CMDQ execution timeout
> > f4be17cd5b14 drm/mediatek: Remove struct cmdq_client
> > c1ec54b7b5af drm/mediatek: Use mailbox rx_callback instead of cmdq_task_cb
> >
> > Without these patches 5.15-rc2 works again on my platform.
> >
> > The commit 'c1ec54b7b5af drm/mediatek: Use mailbox rx_callback instead
> > of cmdq_task_cb' alone introduces lots of warnings in the kernel
> >
> > WARNING: CPU: 0 PID: 0 at drivers/mailbox/mtk-cmdq-mailbox.c:198
> > cmdq_task_exec_done+0xb8/0xe0
>
> I think the WARN_ON in cmdq driver should be remove because that
> warning show that cmdq_task_cb is not used but I that is what I want.
>
> >
> > I think is just a leftover or the mentioned warning, but that confused
> > me a bit doing the bisection. Then, after commit 'f4be17cd5b14
> > drm/mediatek: Remove struct cmdq_client' my system simply gets stuck.
> > For now I don't see any obvious mistake but will dig further.
> >
> > Can I ask you in which platform did you test? And if you can double
> > check if your platform is broken too in current mainline?
>
> I've no environment to test code now. I apply this series because I
> assume Yongqiang has test his patch "Clear pending flag when cmdq
> packet is done".  Before I setup the environment (this may take a long
> time), I would find others to fix this problem.
> According to your information, "c1ec54b7b5af drm/mediatek: Use mailbox
> rx_callback instead of cmdq_task_cb" would cause many warning but
> display still work, right? If so, I think we should focus on
> "f4be17cd5b14 drm/mediatek: Remove struct cmdq_client".
>
> Regards,
> Chun-Kuang.
>
> >
> > Thanks,
> >   Enric
> >
> > > If "drm/mediatek: Remove struct cmdq_client" is the patch cause
> > > display abnormal, I think you could compare code w/ and w/o this
> > > patch. Focus on the value accuracy, such as cmdq_cl and cmdq_chan. And
> > > focus on the flow accuracy, such as mtk_drm_crtc_update_config() and
> > > ddp_cmdq_cb(). If this could not find the problem, I think the latest
> > > way is to break this patch into small patches, changes little in each
> > > small patches and we could finally find out the problem.
> > >
> > > Regards,
> > > Chun-Kuang.
> > >
> > > >
> > > > Unfortunately, after the merge window, different things broke for this
> > > > device, and I didn't finish isolating them, and it is not clear to me
> > > > yet whether the logs I'm getting are useful for this specific issue or
> > > > not. Basically with this series merged the kernel seems to be stuck,
> > > > and the display is not working. Latest message is
> > > >
> > > > [   12.329173] mtk-iommu 10205000.iommu: Partial TLB flush timed out,
> > > > falling back to full flush
> > > >
> > > > Without the series, the kernel goes far and display works, however
> > > > there are other issues affecting the cros-ec, but I think that's
> > > > another issue.
> > > >
> > > > I'll try to dig a bit more, but, meanwhile, if you have any idea
> > > > please let me know.
> > > >
> > > > Thanks,
> > > >  Enric
> > > >
> > > >
> > > > > Regards,
> > > > > Chun-Kuang.
> > > > >
> > > > > >
> > > > > > Changes in v2:
> > > > > > 1. Define mtk_drm_cmdq_pkt_create() and mtk_drm_cmdq_pkt_destroy()
> > > > > >    when CONFIG_MTK_CMDQ is reachable.
> > > > > >
> > > > > > 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
> > > > > >

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