[Intel-xe] [PATCH 2/2] drm/xe: nuke GuC on unload

[Matthew Brost]

On Wed, Aug 23, 2023 at 06:55:53PM +0100, Matthew Auld wrote:
> On PVC unloading followed by reloading the module often results in a
> completely dead machine (seems to be plaguing CI). Resetting the GuC
> like we do at load seems to cure it at least when locally testing this.
> 
> References: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/542
> References: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/597
> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>

Seems reasonible to reset the GuC on driver unload, one question below.

> ---
>  drivers/gpu/drm/xe/xe_guc.c | 16 ++++++++++++++++
>  drivers/gpu/drm/xe/xe_uc.c  |  5 +++++
>  drivers/gpu/drm/xe/xe_uc.h  |  1 +
>  3 files changed, 22 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
> index e102637c0695..bbe06686a706 100644
> --- a/drivers/gpu/drm/xe/xe_guc.c
> +++ b/drivers/gpu/drm/xe/xe_guc.c
> @@ -5,6 +5,8 @@
>  
>  #include "xe_guc.h"
>  
> +#include <drm/drm_managed.h>
> +
>  #include "generated/xe_wa_oob.h"
>  #include "regs/xe_gt_regs.h"
>  #include "regs/xe_guc_regs.h"
> @@ -20,6 +22,7 @@
>  #include "xe_guc_submit.h"
>  #include "xe_mmio.h"
>  #include "xe_platform_types.h"
> +#include "xe_uc.h"
>  #include "xe_uc_fw.h"
>  #include "xe_wa.h"
>  #include "xe_wopcm.h"
> @@ -217,6 +220,15 @@ static void guc_write_params(struct xe_guc *guc)
>  		xe_mmio_write32(gt, SOFT_SCRATCH(1 + i), guc->params[i]);
>  }
>  
> +static void guc_fini(struct drm_device *drm, void *arg)
> +{
> +	struct xe_guc *guc = arg;
> +
> +	xe_force_wake_get(gt_to_fw(guc_to_gt(guc)), XE_FORCEWAKE_ALL);
> +	xe_uc_fini_hw(&guc_to_gt(guc)->uc);
> +	xe_force_wake_put(gt_to_fw(guc_to_gt(guc)), XE_FORCEWAKE_ALL);
> +}
> +
>  int xe_guc_init(struct xe_guc *guc)
>  {
>  	struct xe_device *xe = guc_to_xe(guc);
> @@ -240,6 +252,10 @@ int xe_guc_init(struct xe_guc *guc)
>  	if (ret)
>  		goto out;
>  
> +	ret = drmm_add_action_or_reset(&gt_to_xe(gt)->drm, guc_fini, guc);
> +	if (ret)
> +		goto out;
> +

Any reason this is after xe_guc_ct_init but before xe_guc_pc_init? Seems
like odd placement.

Matt

>  	ret = xe_guc_pc_init(&guc->pc);
>  	if (ret)
>  		goto out;
> diff --git a/drivers/gpu/drm/xe/xe_uc.c b/drivers/gpu/drm/xe/xe_uc.c
> index addd6f2681b9..9c8ce504f4da 100644
> --- a/drivers/gpu/drm/xe/xe_uc.c
> +++ b/drivers/gpu/drm/xe/xe_uc.c
> @@ -167,6 +167,11 @@ int xe_uc_init_hw(struct xe_uc *uc)
>  	return 0;
>  }
>  
> +int xe_uc_fini_hw(struct xe_uc *uc)
> +{
> +	return xe_uc_sanitize_reset(uc);
> +}
> +
>  int xe_uc_reset_prepare(struct xe_uc *uc)
>  {
>  	/* GuC submission not enabled, nothing to do */
> diff --git a/drivers/gpu/drm/xe/xe_uc.h b/drivers/gpu/drm/xe/xe_uc.h
> index 42219b361df5..4109ae7028af 100644
> --- a/drivers/gpu/drm/xe/xe_uc.h
> +++ b/drivers/gpu/drm/xe/xe_uc.h
> @@ -12,6 +12,7 @@ int xe_uc_init(struct xe_uc *uc);
>  int xe_uc_init_hwconfig(struct xe_uc *uc);
>  int xe_uc_init_post_hwconfig(struct xe_uc *uc);
>  int xe_uc_init_hw(struct xe_uc *uc);
> +int xe_uc_fini_hw(struct xe_uc *uc);
>  void xe_uc_gucrc_disable(struct xe_uc *uc);
>  int xe_uc_reset_prepare(struct xe_uc *uc);
>  void xe_uc_stop_prepare(struct xe_uc *uc);
> -- 
> 2.41.0
>