[Intel-gfx] [PATCH v2] drm/i915/guc: Add debug capture of GuC exception

[Michal Wajdeczko]

On Tue, 25 Jun 2019 18:41:07 +0200, Robert M. Fosha  
<robert.m.fosha at intel.com> wrote:

> Detect GuC firmware load failure due to an exception during execution
> in GuC firmware. Output the GuC EIP where exception occurred to dmesg
> for GuC debug information.
>
> v2: correct typos, change debug message and error code returned for
> GuC exception (Michal)
>
> Signed-off-by: Robert M. Fosha <robert.m.fosha at intel.com>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>

let's hope it will never show up

Reviewed-by: Michal Wajdeczko <michal.wajdeczko at intel.com>

> ---
>  drivers/gpu/drm/i915/intel_guc_fw.c  | 7 +++++++
>  drivers/gpu/drm/i915/intel_guc_reg.h | 1 +
>  2 files changed, 8 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_guc_fw.c  
> b/drivers/gpu/drm/i915/intel_guc_fw.c
> index 72cdafd9636a..970f39ef248b 100644
> --- a/drivers/gpu/drm/i915/intel_guc_fw.c
> +++ b/drivers/gpu/drm/i915/intel_guc_fw.c
> @@ -197,6 +197,7 @@ static inline bool guc_ready(struct intel_guc *guc,  
> u32 *status)
> static int guc_wait_ucode(struct intel_guc *guc)
>  {
> +	struct drm_i915_private *i915 = guc_to_i915(guc);
>  	u32 status;
>  	int ret;
> @@ -216,6 +217,12 @@ static int guc_wait_ucode(struct intel_guc *guc)
>  		ret = -ENOEXEC;
>  	}
> +	if ((status & GS_UKERNEL_MASK) == GS_UKERNEL_EXCEPTION) {
> +		DRM_ERROR("GuC firmware exception. EIP: %#x\n",
> +			  intel_uncore_read(&i915->uncore, SOFT_SCRATCH(13)));
> +		ret = -ENXIO;
> +	}
> +
>  	if (ret == 0 && !guc_xfer_completed(guc, &status)) {
>  		DRM_ERROR("GuC is ready, but the xfer %08x is incomplete\n",
>  			  status);
> diff --git a/drivers/gpu/drm/i915/intel_guc_reg.h  
> b/drivers/gpu/drm/i915/intel_guc_reg.h
> index a214f8b71929..d90b88fadb5e 100644
> --- a/drivers/gpu/drm/i915/intel_guc_reg.h
> +++ b/drivers/gpu/drm/i915/intel_guc_reg.h
> @@ -37,6 +37,7 @@
>  #define   GS_UKERNEL_MASK		  (0xFF << GS_UKERNEL_SHIFT)
>  #define   GS_UKERNEL_LAPIC_DONE		  (0x30 << GS_UKERNEL_SHIFT)
>  #define   GS_UKERNEL_DPC_ERROR		  (0x60 << GS_UKERNEL_SHIFT)
> +#define   GS_UKERNEL_EXCEPTION		  (0x70 << GS_UKERNEL_SHIFT)
>  #define   GS_UKERNEL_READY		  (0xF0 << GS_UKERNEL_SHIFT)
>  #define   GS_MIA_SHIFT			16
>  #define   GS_MIA_MASK			  (0x07 << GS_MIA_SHIFT)