Re: [PATCH v2 4/5] drm/xe: Add handler for power management unit errors which require cold-reset

Tauro, Riana
2026-03-30T04:54:20Z

On 3/18/2026 12:10 PM, Mallesh Koujalagi wrote:
> This handler is designed to be called when power management unit errors are
> detected that affect device-level state persisting across warm resets.
Commit message should be clear.
> The
> cold reset recovery method signals to userspace that only a complete device
> power cycle can restore normal operation.
>
> v2:
> - Add use case: Handling errors from power management unit,
> which requires a complete power cycle (cold reset)
> to recover. (Christian)
This is not an addition to the patch. Only add this in cover letter.
>
> Signed-off-by: Mallesh Koujalagi <mallesh.koujalagi@intel.com>
> ---
> drivers/gpu/drm/xe/xe_hw_error.c | 27 +++++++++++++++++++++++++++
> drivers/gpu/drm/xe/xe_hw_error.h | 1 +
> drivers/gpu/drm/xe/xe_ras.c | 3 ++-
> 3 files changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_hw_error.c b/drivers/gpu/drm/xe/xe_hw_error.c
> index 2a31b430570e..ca965a2b092c 100644
> --- a/drivers/gpu/drm/xe/xe_hw_error.c
> +++ b/drivers/gpu/drm/xe/xe_hw_error.c
> @@ -5,6 +5,7 @@
>
> #include <linux/bitmap.h>
> #include <linux/fault-inject.h>
> +#include <drm/drm_drv.h>
>
> #include "regs/xe_gsc_regs.h"
> #include "regs/xe_hw_error_regs.h"
> @@ -542,6 +543,32 @@ static void process_hw_errors(struct xe_device *xe)
> }
> }
>
> +/**
> + * xe_punit_error_handler - Handler for power management unit errors
> + * @xe: device instance
> + *
> + * Handles power management unit errors that affect the device and cannot
> + * be recovered through driver reload, PCIe reset, etc.
> + *
> + * Marks the device as wedged with DRM_WEDGE_RECOVERY_COLD_RESET method
> + * and notifies userspace that a complete device power cycle is required.
> + */
> +void xe_punit_error_handler(struct xe_device *xe)

You can move this to xe_ras

> +{
> + drm_err(&xe->drm, "CRITICAL: PMU error detected\n");

PMU? also means Performance monitoring unit. Please use Punit instead
Keep this consistent in both commit message, kernel-doc and code

> + drm_err(&xe->drm, "Recovery: Device cold reset required\n");
power-cycle/cold-reset. Use consistent wording

Thanks
Riana

> +
> + /* Set cold reset recovery method */
> + xe_device_set_wedged_method(xe, DRM_WEDGE_RECOVERY_COLD_RESET);
> +
> + if (xe_device_wedged(xe)) {
> + drm_dev_wedged_event(&xe->drm, xe->wedged.method, NULL);
> + } else {
> + /* Declare device wedged - will trigger uevent with cold reset method */
> + xe_device_declare_wedged(xe);
> + }
> +}
> +
> /**
> * xe_hw_error_init - Initialize hw errors
> * @xe: xe device instance
> diff --git a/drivers/gpu/drm/xe/xe_hw_error.h b/drivers/gpu/drm/xe/xe_hw_error.h
> index d86e28c5180c..f588320eb94d 100644
> --- a/drivers/gpu/drm/xe/xe_hw_error.h
> +++ b/drivers/gpu/drm/xe/xe_hw_error.h
> @@ -11,5 +11,6 @@ struct xe_tile;
> struct xe_device;
>
> void xe_hw_error_irq_handler(struct xe_tile *tile, const u32 master_ctl);
> +void xe_punit_error_handler(struct xe_device *xe);
> void xe_hw_error_init(struct xe_device *xe);
> #endif
> diff --git a/drivers/gpu/drm/xe/xe_ras.c b/drivers/gpu/drm/xe/xe_ras.c
> index 777321021391..93257d0eaaa0 100644
> --- a/drivers/gpu/drm/xe/xe_ras.c
> +++ b/drivers/gpu/drm/xe/xe_ras.c
> @@ -10,6 +10,7 @@
> #include "xe_survivability_mode.h"
> #include "xe_sysctrl_mailbox.h"
> #include "xe_sysctrl_mailbox_types.h"
> +#include "xe_hw_error.h"
>
> #define COMPUTE_ERROR_SEVERITY_MASK GENMASK(26, 25)
> #define GLOBAL_UNCORR_ERROR 2
> @@ -148,7 +149,7 @@ static enum xe_ras_recovery_action handle_soc_internal_errors(struct xe_device *
> xe_err(xe, "[RAS]: PUNIT %s error detected: 0x%x\n",
> severity_to_str(xe, common_info.severity),
> ieh_error->error_sources_ieh0.punit);
> - /** TODO: Add PUNIT error handling */
> + xe_punit_error_handler(xe);
> action = XE_RAS_RECOVERY_ACTION_DISCONNECT;
> }
> }