[PATCH v1] drm/xe/pm: Wait for lmem ready in resume

[Gupta, Anshuman]

> -----Original Message-----
> From: Poosa, Karthik <karthik.poosa at intel.com>
> Sent: Monday, April 21, 2025 5:00 PM
> To: Gupta, Anshuman <anshuman.gupta at intel.com>; intel-
> xe at lists.freedesktop.org
> Cc: Nilawar, Badal <badal.nilawar at intel.com>; Vivi, Rodrigo
> <rodrigo.vivi at intel.com>
> Subject: Re: [PATCH v1] drm/xe/pm: Wait for lmem ready in resume
> 
> 
> On 15-04-2025 11:01, Poosa, Karthik wrote:
> >
> >
> > On 10-04-2025 17:36, Gupta, Anshuman wrote:
> >>> -----Original Message-----
> >>> From: Poosa, Karthik<karthik.poosa at intel.com>
> >>> Sent: Thursday, April 10, 2025 4:31 PM
> >>> To:intel-xe at lists.freedesktop.org
> >>> Cc: Gupta, Anshuman<anshuman.gupta at intel.com>; Nilawar, Badal
> >>> <badal.nilawar at intel.com>; Vivi, Rodrigo<rodrigo.vivi at intel.com>;
> >>> Poosa, Karthik<karthik.poosa at intel.com>
> >>> Subject: [PATCH v1] drm/xe/pm: Wait for lmem ready in resume
> >>>
> >>> Add wait for LMEM ready during system and runtime resume.
> >>> This wait is there in probe and is missing during resume.
> >>>
> >>> Signed-off-by: Karthik Poosa<karthik.poosa at intel.com>
> >>> ---
> >>>   drivers/gpu/drm/xe/xe_device.c | 2 +-
> >>>   drivers/gpu/drm/xe/xe_device.h | 1 +
> >>>   drivers/gpu/drm/xe/xe_pm.c     | 8 ++++++++
> >>>   3 files changed, 10 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/xe/xe_device.c
> >>> b/drivers/gpu/drm/xe/xe_device.c index 75e753e0a682..4c0d9eb51d1f
> >>> 100644
> >>> --- a/drivers/gpu/drm/xe/xe_device.c
> >>> +++ b/drivers/gpu/drm/xe/xe_device.c
> >>> @@ -630,7 +630,7 @@ static bool verify_lmem_ready(struct xe_device
> *xe)
> >>>   	return !!val;
> >>>   }
> >>>
> >>> -static int wait_for_lmem_ready(struct xe_device *xe)
> >>> +int wait_for_lmem_ready(struct xe_device *xe)
> >>>   {
> >>>   	unsigned long timeout, start;
> >>>
> >>> diff --git a/drivers/gpu/drm/xe/xe_device.h
> >>> b/drivers/gpu/drm/xe/xe_device.h index 0bc3bc8e6803..60bc92f9ab22
> >>> 100644
> >>> --- a/drivers/gpu/drm/xe/xe_device.h
> >>> +++ b/drivers/gpu/drm/xe/xe_device.h
> >>> @@ -47,6 +47,7 @@ int xe_device_probe_early(struct xe_device *xe);
> >>> int xe_device_probe(struct xe_device *xe);  void
> >>> xe_device_remove(struct xe_device *xe);  void
> >>> xe_device_shutdown(struct xe_device *xe);
> >>> +int wait_for_lmem_ready(struct xe_device *xe);
> >>>
> >>>   void xe_device_wmb(struct xe_device *xe);
> >>>
> >>> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> >>> index
> >>> 4e112fbacada..2e59670660c1 100644
> >>> --- a/drivers/gpu/drm/xe/xe_pm.c
> >>> +++ b/drivers/gpu/drm/xe/xe_pm.c
> >>> @@ -182,6 +182,10 @@ int xe_pm_resume(struct xe_device *xe)
> >>>   	if (err)
> >>>   		return err;
> >>>
> >>> +	err = wait_for_lmem_ready(xe);
> >> In Xe we are referring this as a vram.
> >> Do  we have any spec, that document this ?
> I can change the API to wait_for_vram_ready.
> Although I didn't find any specific mention of this in any spec, it's prudent to
> include this wait here, as this is done in probe.
Add file name xe_*  as well prefix to function if it is not static.
Thanks,
Anshuman Gupta.
> >>> +	if (err)
> >>> +		goto err;
> >>> +
> >>>   	xe_display_pm_resume_early(xe);
> >>>
> >>>   	/*
> >>> @@ -478,6 +482,10 @@ int xe_pm_runtime_resume(struct xe_device
> *xe)
> >>>   		if (err)
> >>>   			goto out;
> >>>
> >>> +		err = wait_for_lmem_ready(xe);
> >>> +		if (err)
> >>> +			goto out;
> >>> +
> >>>   		xe_display_pm_resume_early(xe);
> >>>
> >>>   		/*
> >>> --
> >>> 2.25.1