Re: [PATCH v3 04/10] drm/xe/vsec: Use correct pm state get

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

On Mon, Aug 24, 2026 at 09:23:20AM -0700, Michael J. Ruhl wrote:
> Crashlog needs to be collected at all times.  The current pm
> check assumes telemetry only.
> 
> Update read path to enable device for crashlog instances.
> 
> Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> Fixes: 2c402a801c19 ("platform/x86/intel/pmt: support BMG crashlog")

I have the feeling that this patch should be split into 2.
1. with the lock fix and another one that would be the feature
scope increase for the crashlog and watcher, no?!

Or at least mention the mutex in the commit message?

> ---
>  drivers/gpu/drm/xe/xe_vsec.c | 21 +++++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vsec.c b/drivers/gpu/drm/xe/xe_vsec.c
> index bd83a33aef6c..8d99a3770b5a 100644
> --- a/drivers/gpu/drm/xe/xe_vsec.c
> +++ b/drivers/gpu/drm/xe/xe_vsec.c
> @@ -145,6 +145,7 @@ int xe_pmt_telem_read(struct device *dev, u32 guid, u64 *data, loff_t user_offse
>  {
>  	struct xe_device *xe = kdev_to_xe_device(dev);
>  	void __iomem *telem_addr = xe->mmio.regs + BMG_TELEMETRY_OFFSET;
> +	u32 cap_type = FIELD_GET(GUID_CAP_TYPE, guid);
>  	u32 mem_region;
>  	u32 offset;
>  	int ret;
> @@ -158,16 +159,28 @@ int xe_pmt_telem_read(struct device *dev, u32 guid, u64 *data, loff_t user_offse
>  
>  	telem_addr += offset + user_offset;
>  
> -	guard(mutex)(&xe->pmt.lock);
> +	/* Always allow crashlog. Telemetry, only when powered */
> +	switch (cap_type) {
> +	case CRASHLOG:
> +		xe_pm_runtime_get(xe);
> +		break;
> +	case TELEMETRY:
> +		if (!xe_pm_runtime_get_if_active(xe))
> +			return -ENODATA;
> +		break;
> +	case WATCHER:
> +		return -EINVAL;
> +	}
>  
> -	/* indicate that we are not at an appropriate power level */
> -	if (!xe_pm_runtime_get_if_active(xe))
> -		return -ENODATA;
> +	mutex_lock(&xe->pmt.lock);
>  
>  	/* set SoC re-mapper index register based on GUID memory region */
>  	xe->soc_remapper.set_telem_region(xe, mem_region);
>  
>  	memcpy_fromio(data, telem_addr, count);
> +
> +	mutex_unlock(&xe->pmt.lock);
> +
>  	xe_pm_runtime_put(xe);
>  
>  	return count;
> -- 
> 2.43.0
>