Re: [PATCH 1/4] ACPI: APEI: GHES: Use spin_lock_irqsave() for CXL CPER work locks

["Cheatham, Benjamin" <benjamin.cheatham@amd.com>]

On 7/9/2026 11:28 AM, Dave Jiang wrote:
> cxl_cper_post_event() and cxl_cper_post_prot_err() acquire
> cxl_cper_work_lock and cxl_cper_prot_err_work_lock with
> spin_lock_irqsave(). These producers run from ghes_do_proc() in hard IRQ
> context (the GHES IRQ handler) and, for SEA/NMI notifications, from NMI
> context.
> 
> The register/unregister helpers take the same two locks with a plain
> spin_lock() from process context (cxl_ras_init()/cxl_ras_exit() at module
> load and unload). If a GHES error interrupt is delivered to a CPU that is
> holding one of these locks via the plain spin_lock(), the interrupt
> handler's spin_lock_irqsave() on the same lock spins forever against a
> lock the interrupted thread can no longer release.
> 
> Take these locks with spin_lock_irqsave() on the register/unregister
> paths as well.
> 
> Link: https://sashiko.dev/#/patchset/20260617-topics-ahmtib01-ras_ffh_arm_internal_review-v6-0-91f725174aa0@arm.com?part=6
> Fixes: 5e4a264bf8b5 ("acpi/ghes: Process CXL Component Events")
> Fixes: 36f257e3b0ba ("acpi/ghes, cxl/pci: Process CXL CPER Protocol Errors")
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---

Since the Sashiko review is for a different issue and this makes sense to me:
Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>