[PATCH v1] drm/xe/throttle: Log throttle reasons

[Dixit, Ashutosh]

On Fri, 15 Nov 2024 11:54:46 -0800, Matthew Brost wrote:
>
> On Fri, Nov 15, 2024 at 06:26:14PM +0530, Raag Jadav wrote:
> > Log throttle register MMIO reads which will be useful for debugging.
> >
> > Signed-off-by: Raag Jadav <raag.jadav at intel.com>
> > ---
> >  drivers/gpu/drm/xe/xe_gt_throttle.c | 9 ++++++---
> >  1 file changed, 6 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_gt_throttle.c b/drivers/gpu/drm/xe/xe_gt_throttle.c
> > index 03b225364101..0ce21ffc08dc 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_throttle.c
> > +++ b/drivers/gpu/drm/xe/xe_gt_throttle.c
> > @@ -37,15 +37,18 @@ dev_to_gt(struct device *dev)
> >
> >  u32 xe_gt_throttle_get_limit_reasons(struct xe_gt *gt)
> >  {
> > +	struct xe_device *xe = gt_to_xe(gt);
> > +	bool media = xe_gt_is_media_type(gt);
> >	u32 reg;
> >
> > -	xe_pm_runtime_get(gt_to_xe(gt));
> > -	if (xe_gt_is_media_type(gt))
> > +	xe_pm_runtime_get(xe);
> > +	if (media)
> >		reg = xe_mmio_read32(&gt->mmio, MTL_MEDIA_PERF_LIMIT_REASONS);
> >	else
> >		reg = xe_mmio_read32(&gt->mmio, GT0_PERF_LIMIT_REASONS);
> > -	xe_pm_runtime_put(gt_to_xe(gt));
> > +	xe_pm_runtime_put(xe);
> >
> > +	drm_dbg(&xe->drm, "%s reg: 0x%x\n", media ? "media" : "gt", reg);
>
> How often does this happen? i.e. Is this common enough that it will spam
> dmesg when running IGTs. I find messages which spam dmesg very annoying.
> See this patch [1] I posted to remove one of these.

How about reading via debugfs as in i915? Also, looks like we don't have a
means to clear the top 16 'latched' bits yet?

>
> Matt
>
> [1] https://patchwork.freedesktop.org/series/141426/
>
> >	return reg;
> >  }
> >
> > --
> > 2.34.1
> >