Claude review: bridges without VGA support

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

Overall Series Review

Subject: bridges without VGA support
Author: Simon Richter <Simon.Richter@hogyros.de>
Patches: 6
Reviewed: 2026-02-18T06:47:57.209916

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This series by Simon Richter adds error propagation for VGA arbitration failures, motivated by PCI bridges (such as the root bridge in IBM PowerNV) that silently refuse to enable VGA forwarding. The approach is: (1) detect bridge refusal by reading back the VGA control bit after writing it, (2) propagate the error through `pci_set_vga_state` -> `__vga_tryget` -> `vga_get` -> userspace, and (3) add `__must_check` annotations to encourage callers to handle the new failure mode.

The series has a logical structure and addresses a real problem. However, there are two concrete bugs: `vga_tryget()` is not updated to handle the new `ERR_PTR` returns from `__vga_tryget()`, which means it will misreport errors as `-EBUSY`; and the early return from `pci_set_vga_state` when a bridge refuses VGA decode leaves lower bridges with VGA forwarding enabled, creating an inconsistent hardware state. The series also introduces several coding style violations (missing space before `(`, opening brace placement on `if` blocks) that are inconsistent with kernel conventions. The `__must_check` annotations in patches 3 and 5 will generate new compiler warnings for the i915 driver, which doesn't check return values of `vga_get_uninterruptible`.

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Generated by Claude Code Patch Reviewer