[PATCH 0/2] drm/bridge: th1520-dw-hdmi: Two fixes

[PATCH 0/2] drm/bridge: th1520-dw-hdmi: Two fixes

[Felix Gu]

Signed-off-by: Felix Gu <ustc.gu@gmail.com>
---
Felix Gu (2):
      drm/bridge: th1520-dw-hdmi: Fix error check on dw_hdmi_probe() return value
      drm/bridge: th1520-dw-hdmi: Fix remove() callback

 drivers/gpu/drm/bridge/th1520-dw-hdmi.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
base-commit: b5d083a3ed1e2798396d5e491432e887da8d4a06
change-id: 20260321-th1520-f4326138c9bf

Best regards,
-- 
Felix Gu <ustc.gu@gmail.com>

[PATCH 1/2] drm/bridge: th1520-dw-hdmi: Fix error check on dw_hdmi_probe() return value

[Felix Gu]

The error check after calling dw_hdmi_probe() was incorrectly checking
the struct pointer hdmi instead of the probe result hdmi->dw_hdmi.

Fix this by checking the correct variable.

Fixes: 96f30ee0fb9d ("drm/bridge: add a driver for T-Head TH1520 HDMI controller")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
---
 drivers/gpu/drm/bridge/th1520-dw-hdmi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/th1520-dw-hdmi.c b/drivers/gpu/drm/bridge/th1520-dw-hdmi.c
index 389eead5f1c4..c9968ec1823c 100644
--- a/drivers/gpu/drm/bridge/th1520-dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/th1520-dw-hdmi.c
@@ -136,8 +136,8 @@ static int th1520_dw_hdmi_probe(struct platform_device *pdev)
 	plat_data->priv_data = hdmi;
 
 	hdmi->dw_hdmi = dw_hdmi_probe(pdev, plat_data);
-	if (IS_ERR(hdmi))
-		return PTR_ERR(hdmi);
+	if (IS_ERR(hdmi->dw_hdmi))
+		return PTR_ERR(hdmi->dw_hdmi);
 
 	platform_set_drvdata(pdev, hdmi);
 

-- 
2.43.0

Claude review: drm/bridge: th1520-dw-hdmi: Fix error check on dw_hdmi_probe() return value

[Claude Code Review Bot]

Patch Review

**Verdict: Correct, good fix.**

The original code was:
```c
hdmi->dw_hdmi = dw_hdmi_probe(pdev, plat_data);
if (IS_ERR(hdmi))
    return PTR_ERR(hdmi);
```

This is wrong because `hdmi` is the `struct th1520_hdmi *` allocated earlier via `devm_kzalloc()` — it's always a valid kernel pointer, never an ERR_PTR. The error encoding from `dw_hdmi_probe()` is stored in `hdmi->dw_hdmi`, so `IS_ERR(hdmi)` would always be false, causing the driver to silently proceed with an error pointer stored in `hdmi->dw_hdmi`, leading to crashes later.

The fix correctly checks `hdmi->dw_hdmi`:
```c
if (IS_ERR(hdmi->dw_hdmi))
    return PTR_ERR(hdmi->dw_hdmi);
```

No issues. Fixes tag and commit message are accurate.

---
Generated by Claude Code Patch Reviewer

[PATCH 2/2] drm/bridge: th1520-dw-hdmi: Fix remove() callback

[Felix Gu]

This driver stores struct th1520_hdmi * in platform drvdata, but
th1520_dw_hdmi_remove() was reading it back as struct dw_hdmi *
and passing it to dw_hdmi_remove(), so teardown runs on the wrong
pointer.

Retrieve struct th1520_hdmi * from platform drvdata and pass
hdmi->dw_hdmi to dw_hdmi_remove().

Fixes: 96f30ee0fb9d ("drm/bridge: add a driver for T-Head TH1520 HDMI controller")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
---
 drivers/gpu/drm/bridge/th1520-dw-hdmi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/th1520-dw-hdmi.c b/drivers/gpu/drm/bridge/th1520-dw-hdmi.c
index c9968ec1823c..6ec9003a8f3f 100644
--- a/drivers/gpu/drm/bridge/th1520-dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/th1520-dw-hdmi.c
@@ -146,9 +146,9 @@ static int th1520_dw_hdmi_probe(struct platform_device *pdev)
 
 static void th1520_dw_hdmi_remove(struct platform_device *pdev)
 {
-	struct dw_hdmi *hdmi = platform_get_drvdata(pdev);
+	struct th1520_hdmi *hdmi = platform_get_drvdata(pdev);
 
-	dw_hdmi_remove(hdmi);
+	dw_hdmi_remove(hdmi->dw_hdmi);
 }
 
 static const struct of_device_id th1520_dw_hdmi_of_table[] = {

-- 
2.43.0

Claude review: drm/bridge: th1520-dw-hdmi: Fix remove() callback

[Claude Code Review Bot]

Patch Review

**Verdict: Correct, good fix.**

The original code was:
```c
struct dw_hdmi *hdmi = platform_get_drvdata(pdev);
dw_hdmi_remove(hdmi);
```

But `platform_set_drvdata(pdev, hdmi)` in probe stores a `struct th1520_hdmi *`, not a `struct dw_hdmi *`. Casting the wrong type to `struct dw_hdmi *` and passing it to `dw_hdmi_remove()` would result in operating on garbage data — likely memory corruption or a crash on module removal.

The fix correctly retrieves the proper type and dereferences the inner pointer:
```c
struct th1520_hdmi *hdmi = platform_get_drvdata(pdev);
dw_hdmi_remove(hdmi->dw_hdmi);
```

No issues. Both patches are straightforward, well-described, and suitable for merge.

---
Generated by Claude Code Patch Reviewer

Re: [PATCH 0/2] drm/bridge: th1520-dw-hdmi: Two fixes

[Icenowy Zheng]

在 2026-03-21六的 03:12 +0800，Felix Gu写道：
> Signed-off-by: Felix Gu <ustc.gu@gmail.com>
> ---
> Felix Gu (2):
>       drm/bridge: th1520-dw-hdmi: Fix error check on dw_hdmi_probe()
> return value
>       drm/bridge: th1520-dw-hdmi: Fix remove() callback

Both fixes look trivial and let me start to doubt how could I make such
mistakes.

Reviewed-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>

> 
>  drivers/gpu/drm/bridge/th1520-dw-hdmi.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> ---
> base-commit: b5d083a3ed1e2798396d5e491432e887da8d4a06
> change-id: 20260321-th1520-f4326138c9bf
> 
> Best regards,

Claude review: drm/bridge: th1520-dw-hdmi: Two fixes

[Claude Code Review Bot]

Overall Series Review

Subject: drm/bridge: th1520-dw-hdmi: Two fixes
Author: Felix Gu <ustc.gu@gmail.com>
Patches: 4
Reviewed: 2026-03-22T03:24:58.260762

---

This is a clean, correct 2-patch bugfix series for the T-Head TH1520 DW-HDMI bridge driver. Both patches fix real bugs introduced in the original driver commit (`96f30ee0fb9d`). The fixes are minimal, obvious, and correct. The series is ready to merge with appropriate Fixes tags and should be considered for stable backport.

---
Generated by Claude Code Patch Reviewer