[PATCH v2 0/2] Fix error handling for MDP3

[PATCH v2 0/2] Fix error handling for MDP3

[Moudy Ho]

Changes since v1:
- Rename goto label in mdp_comp_clock_on() from "err_unwind"
  to "err_revert" to make more readable.

Hi,
This series fixes some error handling in MDP3 in response to the bug report
submitted by Dan Carpenter (Message ID = YxB1E00e8D6P4W2e@kili)

Moudy Ho (2):
  media: platform: mtk-mdp3: fix error handling in mdp_cmdq_send()
  media: platform: mtk-mdp3: fix error handling about components
    clock_on

 .../platform/mediatek/mdp3/mtk-mdp3-cmdq.c    | 51 ++++++++++---------
 .../platform/mediatek/mdp3/mtk-mdp3-comp.c    | 24 ++++++---
 2 files changed, 45 insertions(+), 30 deletions(-)

-- 
2.18.0

[PATCH v2 1/2] media: platform: mtk-mdp3: fix error handling in mdp_cmdq_send()

[Moudy Ho]

Increase and refine the goto label in mdp_cmdq_send() to avoid
double free and facilitate traceability.
Also, remove redundant work queue event in blocking function
mdp_cmdq_send().

Fixes: 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver")
Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 .../platform/mediatek/mdp3/mtk-mdp3-cmdq.c    | 47 ++++++++++---------
 1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
index 86c054600a08..e194dec8050a 100644
--- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
+++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
@@ -252,10 +252,9 @@ static int mdp_cmdq_pkt_create(struct cmdq_client *client, struct cmdq_pkt *pkt,
 	dma_addr_t dma_addr;
 
 	pkt->va_base = kzalloc(size, GFP_KERNEL);
-	if (!pkt->va_base) {
-		kfree(pkt);
+	if (!pkt->va_base)
 		return -ENOMEM;
-	}
+
 	pkt->buf_size = size;
 	pkt->cl = (void *)client;
 
@@ -368,25 +367,30 @@ int mdp_cmdq_send(struct mdp_dev *mdp, struct mdp_cmdq_param *param)
 	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
 	if (!cmd) {
 		ret = -ENOMEM;
-		goto err_cmdq_data;
+		goto err_cancel_job;
 	}
 
-	if (mdp_cmdq_pkt_create(mdp->cmdq_clt, &cmd->pkt, SZ_16K)) {
-		ret = -ENOMEM;
-		goto err_cmdq_data;
-	}
+	ret = mdp_cmdq_pkt_create(mdp->cmdq_clt, &cmd->pkt, SZ_16K);
+	if (ret)
+		goto err_free_cmd;
 
 	comps = kcalloc(param->config->num_components, sizeof(*comps),
 			GFP_KERNEL);
 	if (!comps) {
 		ret = -ENOMEM;
-		goto err_cmdq_data;
+		goto err_destroy_pkt;
 	}
 
 	path = kzalloc(sizeof(*path), GFP_KERNEL);
 	if (!path) {
 		ret = -ENOMEM;
-		goto err_cmdq_data;
+		goto err_free_comps;
+	}
+
+	ret = mtk_mutex_prepare(mdp->mdp_mutex[MDP_PIPE_RDMA0]);
+	if (ret) {
+		dev_err(dev, "Fail to enable mutex clk\n");
+		goto err_free_path;
 	}
 
 	path->mdp_dev = mdp;
@@ -406,15 +410,13 @@ int mdp_cmdq_send(struct mdp_dev *mdp, struct mdp_cmdq_param *param)
 	ret = mdp_path_ctx_init(mdp, path);
 	if (ret) {
 		dev_err(dev, "mdp_path_ctx_init error\n");
-		goto err_cmdq_data;
+		goto err_free_path;
 	}
 
-	mtk_mutex_prepare(mdp->mdp_mutex[MDP_PIPE_RDMA0]);
-
 	ret = mdp_path_config(mdp, cmd, path);
 	if (ret) {
 		dev_err(dev, "mdp_path_config error\n");
-		goto err_cmdq_data;
+		goto err_free_path;
 	}
 	cmdq_pkt_finalize(&cmd->pkt);
 
@@ -433,7 +435,7 @@ int mdp_cmdq_send(struct mdp_dev *mdp, struct mdp_cmdq_param *param)
 	ret = mdp_comp_clocks_on(&mdp->pdev->dev, cmd->comps, cmd->num_comps);
 	if (ret) {
 		dev_err(dev, "comp %d failed to enable clock!\n", ret);
-		goto err_clock_off;
+		goto err_free_path;
 	}
 
 	dma_sync_single_for_device(mdp->cmdq_clt->chan->mbox->dev,
@@ -450,17 +452,20 @@ int mdp_cmdq_send(struct mdp_dev *mdp, struct mdp_cmdq_param *param)
 	return 0;
 
 err_clock_off:
-	mtk_mutex_unprepare(mdp->mdp_mutex[MDP_PIPE_RDMA0]);
 	mdp_comp_clocks_off(&mdp->pdev->dev, cmd->comps,
 			    cmd->num_comps);
-err_cmdq_data:
+err_free_path:
+	mtk_mutex_unprepare(mdp->mdp_mutex[MDP_PIPE_RDMA0]);
 	kfree(path);
-	atomic_dec(&mdp->job_count);
-	wake_up(&mdp->callback_wq);
-	if (cmd && cmd->pkt.buf_size > 0)
-		mdp_cmdq_pkt_destroy(&cmd->pkt);
+err_free_comps:
 	kfree(comps);
+err_destroy_pkt:
+	mdp_cmdq_pkt_destroy(&cmd->pkt);
+err_free_cmd:
 	kfree(cmd);
+err_cancel_job:
+	atomic_dec(&mdp->job_count);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(mdp_cmdq_send);
-- 
2.18.0

[PATCH v2 2/2] media: platform: mtk-mdp3: fix error handling about components clock_on

[Moudy Ho]

Add goto statement in mdp_comp_clock_on() to avoid error code not being
propagated or returning positive values.
This change also performs a well-timed clock_off when an error occurs, and
reduces unnecessary error logging in mdp_cmdq_send().

Fixes: 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver")
Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>
---
 .../platform/mediatek/mdp3/mtk-mdp3-cmdq.c    |  4 +---
 .../platform/mediatek/mdp3/mtk-mdp3-comp.c    | 24 ++++++++++++++-----
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
index e194dec8050a..124c1b96e96b 100644
--- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
+++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-cmdq.c
@@ -433,10 +433,8 @@ int mdp_cmdq_send(struct mdp_dev *mdp, struct mdp_cmdq_param *param)
 	cmd->mdp_ctx = param->mdp_ctx;
 
 	ret = mdp_comp_clocks_on(&mdp->pdev->dev, cmd->comps, cmd->num_comps);
-	if (ret) {
-		dev_err(dev, "comp %d failed to enable clock!\n", ret);
+	if (ret)
 		goto err_free_path;
-	}
 
 	dma_sync_single_for_device(mdp->cmdq_clt->chan->mbox->dev,
 				   cmd->pkt.pa_base, cmd->pkt.cmd_buf_size,
diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
index d3eaf8884412..7bc05f42a23c 100644
--- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
+++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
@@ -699,12 +699,22 @@ int mdp_comp_clock_on(struct device *dev, struct mdp_comp *comp)
 			dev_err(dev,
 				"Failed to enable clk %d. type:%d id:%d\n",
 				i, comp->type, comp->id);
-			pm_runtime_put(comp->comp_dev);
-			return ret;
+			goto err_revert;
 		}
 	}
 
 	return 0;
+
+err_revert:
+	while (--i >= 0) {
+		if (IS_ERR_OR_NULL(comp->clks[i]))
+			continue;
+		clk_disable_unprepare(comp->clks[i]);
+	}
+	if (comp->comp_dev)
+		pm_runtime_put_sync(comp->comp_dev);
+
+	return ret;
 }
 
 void mdp_comp_clock_off(struct device *dev, struct mdp_comp *comp)
@@ -723,11 +733,13 @@ void mdp_comp_clock_off(struct device *dev, struct mdp_comp *comp)
 
 int mdp_comp_clocks_on(struct device *dev, struct mdp_comp *comps, int num)
 {
-	int i;
+	int i, ret;
 
-	for (i = 0; i < num; i++)
-		if (mdp_comp_clock_on(dev, &comps[i]) != 0)
-			return ++i;
+	for (i = 0; i < num; i++) {
+		ret = mdp_comp_clock_on(dev, &comps[i]);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }
-- 
2.18.0

Re: [PATCH v2 2/2] media: platform: mtk-mdp3: fix error handling about components clock_on

[AngeloGioacchino Del Regno]

Il 03/10/22 09:08, Moudy Ho ha scritto:
> Add goto statement in mdp_comp_clock_on() to avoid error code not being
> propagated or returning positive values.
> This change also performs a well-timed clock_off when an error occurs, and
> reduces unnecessary error logging in mdp_cmdq_send().
> 
> Fixes: 61890ccaefaf ("media: platform: mtk-mdp3: add MediaTek MDP3 driver")
> Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>