Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [High] drm/panfrost: missing error check on pm_runtime_get_sync() in device removal causes SError --
commit c158c940eec9a323d868411adbbd13b59c6449b8 Author: Adrián Larumbe <[email protected]> drm/panfrost: Fix PM refcnt and autosuspend issues at device probe/remove This commit fixes issues where the panfrost device PM usage count was left at 0 after probe failure, or increased monotonically after every module reload. It manually adjusts the PM refcnt at probe and removal, and ensures autosuspend functions are called properly. > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c > b/drivers/gpu/drm/panfrost/panfrost_drv.c > index 55fc22e8d4d4e..907d4a14a0b55 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_drv.c > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c [ ... ] > @@ -884,9 +892,12 @@ static void panfrost_remove(struct platform_device *pdev) > drm_dev_unregister(&pfdev->base); > > pm_runtime_get_sync(pfdev->base.dev); > + pm_runtime_dont_use_autosuspend(pfdev->base.dev); > pm_runtime_disable(pfdev->base.dev); > panfrost_device_fini(pfdev); [Severity: High] Does ignoring the return value of pm_runtime_get_sync() in panfrost_remove() allow the driver to write to unpowered hardware? During device removal, if the power domain or regulators fail to resume the device, pm_runtime_get_sync() returns a negative error code. Because the code proceeds unconditionally to call panfrost_device_fini(), it invokes panfrost_gpu_fini() and panfrost_perfcnt_fini(), which perform direct MMIO register writes (such as to SHADER_PWROFF_LO and GPU_PERFCNT_CFG). Accessing these registers while the hardware is physically powered off can cause an Oops due to a synchronous external abort on ARM architectures. Note that even if follow-up patches attempt to address this by wrapping the call in drm_WARN_ON(), that does not abort or bypass the subsequent hardware accesses. The system would still crash following the warning. > pm_runtime_set_suspended(pfdev->base.dev); > + pm_runtime_put_noidle(pfdev->base.dev); > + > } -- Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=6
