Re: [PATCH 1/3] drm/xe: early-return for SR-IOV VF in C6 funcs

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Aug 25, 2025 at 03:32:17PM -0700, Xin Wang wrote:
> VF drivers can't access any of gtidle control registers. By
> returning early when IS_SRIOV_VF() is true, we avoid executing
> the assertions.
> 
> Suggested-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

I haven't suggested this patch. The only suggestion I gave was if you
really want to touch the xe_device_assert_mem_access that you should
do in a separate patch with proper justification.

The justification above still doesn't explain why you want so badly
to remove of move the xe_device_assert_mem_access.

Better to just give up on this and simply do not touch the
xe_device_assert_mem_access

Thanks,
Rodrigo.

> Signed-off-by: Xin Wang <x.wang@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_gt_idle.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_idle.c b/drivers/gpu/drm/xe/xe_gt_idle.c
> index ffb210216aa9..611c506bdad1 100644
> --- a/drivers/gpu/drm/xe/xe_gt_idle.c
> +++ b/drivers/gpu/drm/xe/xe_gt_idle.c
> @@ -377,12 +377,12 @@ int xe_gt_idle_init(struct xe_gt_idle *gtidle)
>  
>  void xe_gt_idle_enable_c6(struct xe_gt *gt)
>  {
> -	xe_device_assert_mem_access(gt_to_xe(gt));
> -	xe_force_wake_assert_held(gt_to_fw(gt), XE_FW_GT);
> -
>  	if (IS_SRIOV_VF(gt_to_xe(gt)))
>  		return;
>  
> +	xe_device_assert_mem_access(gt_to_xe(gt));
> +	xe_force_wake_assert_held(gt_to_fw(gt), XE_FW_GT);
> +
>  	/* Units of 1280 ns for a total of 5s */
>  	xe_mmio_write32(&gt->mmio, RC_IDLE_HYSTERSIS, 0x3B9ACA);
>  	/* Enable RC6 */
> @@ -392,12 +392,12 @@ void xe_gt_idle_enable_c6(struct xe_gt *gt)
>  
>  void xe_gt_idle_disable_c6(struct xe_gt *gt)
>  {
> -	xe_device_assert_mem_access(gt_to_xe(gt));
> -	xe_force_wake_assert_held(gt_to_fw(gt), XE_FW_GT);
> -
>  	if (IS_SRIOV_VF(gt_to_xe(gt)))
>  		return;
>  
> +	xe_device_assert_mem_access(gt_to_xe(gt));
> +	xe_force_wake_assert_held(gt_to_fw(gt), XE_FW_GT);
> +
>  	xe_mmio_write32(&gt->mmio, RC_CONTROL, 0);
>  	xe_mmio_write32(&gt->mmio, RC_STATE, 0);
>  }
> -- 
> 2.43.0
>