[PATCH] drm/xe: Add helper function to inject fault into ct_dead_capture()

[K V P, Satyanarayana]

Hi
> -----Original Message-----
> From: Jani Nikula <jani.nikula at linux.intel.com>
> Sent: Wednesday, April 30, 2025 5:32 PM
> To: K V P, Satyanarayana <satyanarayana.k.v.p at intel.com>; intel-
> xe at lists.freedesktop.org
> Cc: K V P, Satyanarayana <satyanarayana.k.v.p at intel.com>; Harrison, John C
> <john.c.harrison at intel.com>; Chauhan, Aditya <aditya.chauhan at intel.com>
> Subject: Re: [PATCH] drm/xe: Add helper function to inject fault into
> ct_dead_capture()
> 
> On Tue, 29 Apr 2025, Satyanarayana K V P <satyanarayana.k.v.p at intel.com>
> wrote:
> > When injecting fault to xe_guc_ct_send_recv() & xe_guc_mmio_send_recv()
> > functions, the CI test systems are going out of space and crashing. To
> > avoid this issue, a new helper function is created and when fault is injected
> > into this xe_should_fail_ct_dead_capture() helper function, ct dead capture
> is
> > avoided which suppresses ct dumps in the log.
> >
> > Signed-off-by: Satyanarayana K V P <satyanarayana.k.v.p at intel.com>
> > Suggested-by: John Harrison <John.C.Harrison at Intel.com>
> > Tested-by: Aditya Chauhan <aditya.chauhan at intel.com>
> > ---
> >  drivers/gpu/drm/xe/xe_guc_ct.c | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c
> b/drivers/gpu/drm/xe/xe_guc_ct.c
> > index 2447de0ebedf..3a49e432f74a 100644
> > --- a/drivers/gpu/drm/xe/xe_guc_ct.c
> > +++ b/drivers/gpu/drm/xe/xe_guc_ct.c
> > @@ -1770,6 +1770,12 @@ void xe_guc_ct_print(struct xe_guc_ct *ct,
> struct drm_printer *p, bool want_ctb)
> >  }
> >
> >  #if IS_ENABLED(CONFIG_DRM_XE_DEBUG)
> > +static noinline int xe_should_fail_ct_dead_capture(void)
> 
> IMO noinline needs an explanation. I can guess, but let's not make
> everyone guess.
> 
> BR,
> Jani.
> 
Added explanation and sent new version.
-Satya.
> > +{
> > +	return 0;
> > +}
> > +ALLOW_ERROR_INJECTION(xe_should_fail_ct_dead_capture, ERRNO);
> > +
> >  static void ct_dead_capture(struct xe_guc_ct *ct, struct guc_ctb *ctb, u32
> reason_code)
> >  {
> >  	struct xe_guc_log_snapshot *snapshot_log;
> > @@ -1778,6 +1784,13 @@ static void ct_dead_capture(struct xe_guc_ct
> *ct, struct guc_ctb *ctb, u32 reaso
> >  	unsigned long flags;
> >  	bool have_capture;
> >
> > +	/*
> > +	 * Huge dump is getting generated when injecting error for guc
> CT/MMIO
> > +	 * functions. So, let us suppress the dump when fault is injected.
> > +	 */
> > +	if (xe_should_fail_ct_dead_capture())
> > +		return;
> > +
> >  	if (ctb)
> >  		ctb->info.broken = true;
> 
> --
> Jani Nikula, Intel