Claude review: Re: [PATCH v2 2/2] drm/bridge: lt9211: Add drive-strength-microamp DT property

[Claude Code Review Bot <claude-review@example.com>]

Patch Review

The driver patch adds:
- A `static const u8` lookup table mapping register index to microamp value
- A `u8 lvds_hsdrv_isel` field in the `lt9211` struct
- DT parsing in `lt9211_parse_dt()`
- The register write change in `lt9211_configure_tx()`

**Register change is correct:**
```c
-		{ 0x823f, 0x48 },
+		/* bits 3:0: RG_MLTX_HSDRV_ISEL, LVDS TX driver current */
+		{ 0x823f, 0x40 | ctx->lvds_hsdrv_isel },
```
Original `0x48` = `0100_1000` — bit 6 set, bits 3:0 = 8. New code: `0x40` (bit 6) OR'd with the 4-bit index (0–15), giving range `0x40`–`0x4F`. Default index 8 → `0x48`. Matches.

**DT parsing logic is sound:**
```c
+	ctx->lvds_hsdrv_isel = 8; /* default: 25 uA */
+	ret = of_property_read_u32(dev->of_node, "drive-strength-microamp",
+				   &microamp);
+	if (!ret) {
+		for (i = 0; i < ARRAY_SIZE(lt9211_hsdrv_microamp); i++) {
+			if (lt9211_hsdrv_microamp[i] == microamp) {
+				ctx->lvds_hsdrv_isel = i;
+				break;
+			}
+		}
+		if (i == ARRAY_SIZE(lt9211_hsdrv_microamp)) {
+			dev_err(dev, "Invalid drive-strength-microamp value %u\n",
+				microamp);
+			return -EINVAL;
+		}
+	} else if (ret != -EINVAL) {
+		dev_warn(dev, "Failed to read drive-strength-microamp: %d, using default\n",
+			 ret);
+	}
```

The three-way handling is correct: success → lookup, `-EINVAL` → property absent (silent default), other error → warn and continue with default. The linear scan of 16 entries is fine for a one-time probe path.

**Minor observations (non-blocking):**

1. The existing driver uses `of_property_read_u32()` via `dev->of_node`, which is consistent with the driver's existing OF usage (`of_graph_get_port_by_id`, etc.). Some reviewers may suggest `device_property_read_u32(dev, ...)` as the more generic API, but given this driver is inherently OF-only, either is acceptable.

2. The `dev_err` path for an invalid microamp value would only trigger if the DT binding schema validation is bypassed (since the binding constrains values via enum). Returning `-EINVAL` here is still the right defensive choice.

No functional issues.

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Generated by Claude Code Patch Reviewer