[Intel-xe] [PATCH] drm/xe: Donot apply forcewake while reading actual frequency

[Gupta, Anshuman]

> -----Original Message-----
> From: Nilawar, Badal <badal.nilawar at intel.com>
> Sent: Wednesday, June 7, 2023 1:40 PM
> To: intel-xe at lists.freedesktop.org
> Cc: Gupta, Anshuman <anshuman.gupta at intel.com>; Belgaumkar, Vinay
> <vinay.belgaumkar at intel.com>
> Subject: [PATCH] drm/xe: Donot apply forcewake while reading actual
> frequency
> 
> The registers RPSTAT1, MTL_MIRROR_TARGET_WP1 doesn't fall under any of
> the forcewake domain so doesn't require forcewake to be read.
> When GT in RC6 frequency reported will be 0.
Please mention Bspec index.
> 
> Fixes: 7dbca224f176 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Checkpatch has warned on avoce commit hash.
Br,
Anshuman.
> 
> Signed-off-by: Badal Nilawar <badal.nilawar at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_guc_pc.c | 10 +---------
>  1 file changed, 1 insertion(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c
> b/drivers/gpu/drm/xe/xe_guc_pc.c index 67faa9ee0006..d04600b943e4
> 100644
> --- a/drivers/gpu/drm/xe/xe_guc_pc.c
> +++ b/drivers/gpu/drm/xe/xe_guc_pc.c
> @@ -371,14 +371,8 @@ static ssize_t freq_act_show(struct device *dev,
>  	ssize_t ret;
> 
>  	xe_device_mem_access_get(gt_to_xe(gt));
> -	/*
> -	 * When in RC6, actual frequency is 0. Let's block RC6 so we are able
> -	 * to verify that our freq requests are really happening.
> -	 */
> -	ret = xe_force_wake_get(gt_to_fw(gt), XE_FORCEWAKE_ALL);
> -	if (ret)
> -		goto out;
> 
> +	/* When in RC6, actual frequency reported will be 0. */
>  	if (xe->info.platform == XE_METEORLAKE) {
>  		freq = xe_mmio_read32(gt, MTL_MIRROR_TARGET_WP1);
>  		freq = REG_FIELD_GET(MTL_CAGF_MASK, freq); @@ -389,8
> +383,6 @@ static ssize_t freq_act_show(struct device *dev,
> 
>  	ret = sysfs_emit(buf, "%d\n", decode_freq(freq));
> 
> -	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt),
> XE_FORCEWAKE_ALL));
> -out:
>  	xe_device_mem_access_put(gt_to_xe(gt));
>  	return ret;
>  }
> --
> 2.25.1