Claude review: drm/bridge: samsung-dsim: fix TE GPIO ownership

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

Patch Review

**The bug is real and well-described.** The original code at line 1865 used `devm_gpiod_get_optional()`, but both error and teardown paths manually call `gpiod_put()`. On device detach, devres would fire and double-free the descriptor.

**The fix is correct:**

1. **`devm_gpiod_get_optional()` → `gpiod_get_optional()`** (line 1865): This removes the devres registration, making the manual `gpiod_put()` calls the sole cleanup mechanism. Correct.

2. **`dsi->te_gpio = NULL` after `gpiod_put()` in the error path** (line 1878): Good. Without this, if `samsung_dsim_register_te_irq()` fails and the caller (or a later re-attach) checks `dsi->te_gpio`, it would see a dangling pointer. This is especially relevant since `samsung_dsim_unregister_te_irq()` is called unconditionally in `samsung_dsim_host_detach()` (line 2012) — with a stale pointer that would trigger a use-after-free.

3. **`dsi->te_gpio = NULL` after `gpiod_put()` in the unregister path** (line 1890): Good defensive practice. Protects against double-unregister if `samsung_dsim_host_detach()` were ever called twice, and makes re-attach safe.

**One minor pre-existing nit (not introduced by this patch):** In the `IS_ERR()` path (line 1868-1869), the function returns an error but leaves `dsi->te_gpio` set to an error pointer. If `samsung_dsim_enable_irq()` or `samsung_dsim_disable_irq()` were called after a failed `register_te_irq()`, the `if (dsi->te_gpio)` check at lines 1606/1612 would be true (error pointers are non-NULL), leading to `gpiod_to_irq()` on an invalid descriptor. In the current call flow this doesn't happen because `register_te_irq` failure causes `samsung_dsim_host_attach` to bail out at `err_remove_bridge` before the bridge is usable, but it's still a latent hazard. A `dsi->te_gpio = NULL` or wrapping the return in a local variable would tighten it up. But that's pre-existing and out of scope for this patch.

**Reviewed-by worthy.** The commit message is clear, the Fixes tag is appropriate, the change is minimal and correct.

---
Generated by Claude Code Patch Reviewer