From mboxrd@z Thu Jan  1 00:00:00 1970
From: Claude Code Review Bot <claude-review@example.com>
To: dri-devel-reviews@example.com
Subject: Claude review: drm/rockchip: dw_hdmi: Propagate bus format to display driver
Date: Sat, 16 May 2026 16:14:40 +1000
Message-ID: <review-patch10-20260510183114.1248840-11-jonas@kwiboo.se>
In-Reply-To: <20260510183114.1248840-11-jonas@kwiboo.se>
References: <20260510183114.1248840-1-jonas@kwiboo.se> <20260510183114.1248840-11-jonas@kwiboo.se>
X-Mailer: Claude Code Patch Reviewer
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0

Patch Review

**Status: Bug found**

This patch reads the negotiated bus format from the bridge state and maps it to the rockchip output mode (AAAA or YUV420).

**Bug**: In `dw_hdmi_rockchip_get_bus_format()`:

```c
bridge_state = drm_atomic_get_bridge_state(conn_state->state, bridge);
if (!bridge_state)
	return 0;
```

`drm_atomic_get_bridge_state()` returns `ERR_CAST()` on failure (i.e., `ERR_PTR`), **not** NULL. This NULL check will never catch an error. The code will proceed with an `ERR_PTR` value in `bridge_state` and dereference it, causing a crash.

This should be:
```c
if (IS_ERR(bridge_state))
	return 0;
```

Or better, since this is called from `atomic_check`, the error should be propagated:
```c
if (IS_ERR(bridge_state))
	return PTR_ERR(bridge_state);
```

But that would require changing the return type of `dw_hdmi_rockchip_get_bus_format()` to handle errors. The simplest safe fix is to use `IS_ERR(bridge_state)`.

**Minor**: The commit message has a typo: "inpact" should be "impact".

**Additional note**: The `__free(drm_bridge_put)` cleanup annotation on `bridge` is a nice use of scope-based resource management for the bridge reference obtained from `drm_bridge_chain_get_first_bridge()`.

The `MEDIA_BUS_FMT_FIXED` fallthrough to `MEDIA_BUS_FMT_RGB888_1X24` is the right default behavior. The switch covers RGB, YCbCr 4:4:4, and YCbCr 4:2:0 at both 8 and 10 bit depths.

The `s->bus_format = bus_format` assignment correctly propagates the format to `rockchip_crtc_state`, which has the `bus_format` field (verified in `rockchip_drm_drv.h`).

---
Generated by Claude Code Patch Reviewer