[PATCH 0/2] Remove some hacks required for GuC 62.0.0

[PATCH 0/2] Remove some hacks required for GuC 62.0.0

[Matthew Brost]

Remove a hack required because schedule disable done G2H was received
before context reset G2H in GuC firmware 62.0.0. Since we have upgraded
69.0.3, this is no longer required.

Also revive selftest which proves this works before / after change.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>

Matthew Brost (2):
  drm/i915/selftests: Add a cancel request selftest that triggers a
    reset
  drm/i915/guc: Remove hacks for reset and schedule disable G2H being
    received out of order

 .../gpu/drm/i915/gt/uc/intel_guc_submission.c |  30 +----
 drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
 2 files changed, 119 insertions(+), 28 deletions(-)

-- 
2.34.1

[PATCH 1/2] drm/i915/selftests: Add a cancel request selftest that triggers a reset

[Matthew Brost]

Add a cancel request selftest that results in an engine reset to cancel
the request as it is non-preemptable. Also insert a NOP request after
the cancelled request and confirm that it completes successfully.

v2:
 (Tvrtko)
  - Skip test if preemption timeout compiled out
  - Skip test if engine reset isn't supported
  - Update debug prints to be more descriptive
v3:
  - Add comment explaining test

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
 1 file changed, 117 insertions(+)

diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
index 7f66f6d299b26..f78de99d5ae1e 100644
--- a/drivers/gpu/drm/i915/selftests/i915_request.c
+++ b/drivers/gpu/drm/i915/selftests/i915_request.c
@@ -782,6 +782,115 @@ static int __cancel_completed(struct intel_engine_cs *engine)
 	return err;
 }
 
+/*
+ * Test to prove a non-preemptable request can be cancelled and a subsequent
+ * request on the same context can successfully complete after cancallation.
+ *
+ * Testing methodology is to create non-preemptable request and submit it,
+ * wait for spinner to start, create a NOP request and submit it, cancel the
+ * spinner, wait for spinner to complete and verify it failed with an error,
+ * finally wait for NOP request to complete verify it succeeded without an
+ * error. Preemption timeout also reduced / restored so test runs in a timely
+ * maner.
+ */
+static int __cancel_reset(struct drm_i915_private *i915,
+			  struct intel_engine_cs *engine)
+{
+	struct intel_context *ce;
+	struct igt_spinner spin;
+	struct i915_request *rq, *nop;
+	unsigned long preempt_timeout_ms;
+	int err = 0;
+
+	if (!CONFIG_DRM_I915_PREEMPT_TIMEOUT ||
+	    !intel_has_reset_engine(engine->gt))
+		return 0;
+
+	preempt_timeout_ms = engine->props.preempt_timeout_ms;
+	engine->props.preempt_timeout_ms = 100;
+
+	if (igt_spinner_init(&spin, engine->gt))
+		goto out_restore;
+
+	ce = intel_context_create(engine);
+	if (IS_ERR(ce)) {
+		err = PTR_ERR(ce);
+		goto out_spin;
+	}
+
+	rq = igt_spinner_create_request(&spin, ce, MI_NOOP);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto out_ce;
+	}
+
+	pr_debug("%s: Cancelling active non-preemptable request\n",
+		 engine->name);
+	i915_request_get(rq);
+	i915_request_add(rq);
+	if (!igt_wait_for_spinner(&spin, rq)) {
+		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+		pr_err("Failed to start spinner on %s\n", engine->name);
+		intel_engine_dump(engine, &p, "%s\n", engine->name);
+		err = -ETIME;
+		goto out_rq;
+	}
+
+	nop = intel_context_create_request(ce);
+	if (IS_ERR(nop))
+		goto out_nop;
+	i915_request_get(nop);
+	i915_request_add(nop);
+
+	i915_request_cancel(rq, -EINTR);
+
+	if (i915_request_wait(rq, 0, HZ) < 0) {
+		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+		pr_err("%s: Failed to cancel hung request\n", engine->name);
+		intel_engine_dump(engine, &p, "%s\n", engine->name);
+		err = -ETIME;
+		goto out_nop;
+	}
+
+	if (rq->fence.error != -EINTR) {
+		pr_err("%s: fence not cancelled (%u)\n",
+		       engine->name, rq->fence.error);
+		err = -EINVAL;
+		goto out_nop;
+	}
+
+	if (i915_request_wait(nop, 0, HZ) < 0) {
+		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+		pr_err("%s: Failed to complete nop request\n", engine->name);
+		intel_engine_dump(engine, &p, "%s\n", engine->name);
+		err = -ETIME;
+		goto out_nop;
+	}
+
+	if (nop->fence.error != 0) {
+		pr_err("%s: Nop request errored (%u)\n",
+		       engine->name, nop->fence.error);
+		err = -EINVAL;
+	}
+
+out_nop:
+	i915_request_put(nop);
+out_rq:
+	i915_request_put(rq);
+out_ce:
+	intel_context_put(ce);
+out_spin:
+	igt_spinner_fini(&spin);
+out_restore:
+	engine->props.preempt_timeout_ms = preempt_timeout_ms;
+	if (err)
+		pr_err("%s: %s error %d\n", __func__, engine->name, err);
+	return err;
+}
+
 static int live_cancel_request(void *arg)
 {
 	struct drm_i915_private *i915 = arg;
@@ -814,6 +923,14 @@ static int live_cancel_request(void *arg)
 			return err;
 		if (err2)
 			return err2;
+
+		/* Expects reset so call outside of igt_live_test_* */
+		err = __cancel_reset(i915, engine);
+		if (err)
+			return err;
+
+		if (igt_flush_test(i915))
+			return -EIO;
 	}
 
 	return 0;
-- 
2.34.1

Re: [PATCH 1/2] drm/i915/selftests: Add a cancel request selftest that triggers a reset

[John Harrison]

On 1/11/2022 15:11, Matthew Brost wrote:
> Add a cancel request selftest that results in an engine reset to cancel
> the request as it is non-preemptable. Also insert a NOP request after
> the cancelled request and confirm that it completes successfully.
>
> v2:
>   (Tvrtko)
>    - Skip test if preemption timeout compiled out
>    - Skip test if engine reset isn't supported
>    - Update debug prints to be more descriptive
> v3:
>    - Add comment explaining test
>
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
>   drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
>   1 file changed, 117 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
> index 7f66f6d299b26..f78de99d5ae1e 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_request.c
> +++ b/drivers/gpu/drm/i915/selftests/i915_request.c
> @@ -782,6 +782,115 @@ static int __cancel_completed(struct intel_engine_cs *engine)
>   	return err;
>   }
>   
> +/*
> + * Test to prove a non-preemptable request can be cancelled and a subsequent
> + * request on the same context can successfully complete after cancallation.
cancellation

> + *
> + * Testing methodology is to create non-preemptable request and submit it,
a non-preemptible

> + * wait for spinner to start, create a NOP request and submit it, cancel the
> + * spinner, wait for spinner to complete and verify it failed with an error,
> + * finally wait for NOP request to complete verify it succeeded without an
> + * error. Preemption timeout also reduced / restored so test runs in a timely
> + * maner.
> + */
> +static int __cancel_reset(struct drm_i915_private *i915,
> +			  struct intel_engine_cs *engine)
> +{
> +	struct intel_context *ce;
> +	struct igt_spinner spin;
> +	struct i915_request *rq, *nop;
> +	unsigned long preempt_timeout_ms;
> +	int err = 0;
> +
> +	if (!CONFIG_DRM_I915_PREEMPT_TIMEOUT ||
Does this matter? The test is overriding the default anyway.

> +	    !intel_has_reset_engine(engine->gt))
> +		return 0;
> +
> +	preempt_timeout_ms = engine->props.preempt_timeout_ms;
> +	engine->props.preempt_timeout_ms = 100;
> +
> +	if (igt_spinner_init(&spin, engine->gt))
> +		goto out_restore;
> +
> +	ce = intel_context_create(engine);
> +	if (IS_ERR(ce)) {
> +		err = PTR_ERR(ce);
> +		goto out_spin;
> +	}
> +
> +	rq = igt_spinner_create_request(&spin, ce, MI_NOOP);
> +	if (IS_ERR(rq)) {
> +		err = PTR_ERR(rq);
> +		goto out_ce;
> +	}
> +
> +	pr_debug("%s: Cancelling active non-preemptable request\n",
> +		 engine->name);
> +	i915_request_get(rq);
> +	i915_request_add(rq);
> +	if (!igt_wait_for_spinner(&spin, rq)) {
> +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> +
> +		pr_err("Failed to start spinner on %s\n", engine->name);
> +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> +		err = -ETIME;
> +		goto out_rq;
> +	}
> +
> +	nop = intel_context_create_request(ce);
> +	if (IS_ERR(nop))
> +		goto out_nop;
Should be out_rq?

John.


> +	i915_request_get(nop);
> +	i915_request_add(nop);
> +
> +	i915_request_cancel(rq, -EINTR);
> +
> +	if (i915_request_wait(rq, 0, HZ) < 0) {
> +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> +
> +		pr_err("%s: Failed to cancel hung request\n", engine->name);
> +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> +		err = -ETIME;
> +		goto out_nop;
> +	}
> +
> +	if (rq->fence.error != -EINTR) {
> +		pr_err("%s: fence not cancelled (%u)\n",
> +		       engine->name, rq->fence.error);
> +		err = -EINVAL;
> +		goto out_nop;
> +	}
> +
> +	if (i915_request_wait(nop, 0, HZ) < 0) {
> +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> +
> +		pr_err("%s: Failed to complete nop request\n", engine->name);
> +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> +		err = -ETIME;
> +		goto out_nop;
> +	}
> +
> +	if (nop->fence.error != 0) {
> +		pr_err("%s: Nop request errored (%u)\n",
> +		       engine->name, nop->fence.error);
> +		err = -EINVAL;
> +	}
> +
> +out_nop:
> +	i915_request_put(nop);
> +out_rq:
> +	i915_request_put(rq);
> +out_ce:
> +	intel_context_put(ce);
> +out_spin:
> +	igt_spinner_fini(&spin);
> +out_restore:
> +	engine->props.preempt_timeout_ms = preempt_timeout_ms;
> +	if (err)
> +		pr_err("%s: %s error %d\n", __func__, engine->name, err);
> +	return err;
> +}
> +
>   static int live_cancel_request(void *arg)
>   {
>   	struct drm_i915_private *i915 = arg;
> @@ -814,6 +923,14 @@ static int live_cancel_request(void *arg)
>   			return err;
>   		if (err2)
>   			return err2;
> +
> +		/* Expects reset so call outside of igt_live_test_* */
> +		err = __cancel_reset(i915, engine);
> +		if (err)
> +			return err;
> +
> +		if (igt_flush_test(i915))
> +			return -EIO;
>   	}
>   
>   	return 0;

Re: [PATCH 1/2] drm/i915/selftests: Add a cancel request selftest that triggers a reset

[Matthew Brost]

On Thu, Jan 13, 2022 at 09:33:12AM -0800, John Harrison wrote:
> On 1/11/2022 15:11, Matthew Brost wrote:
> > Add a cancel request selftest that results in an engine reset to cancel
> > the request as it is non-preemptable. Also insert a NOP request after
> > the cancelled request and confirm that it completes successfully.
> > 
> > v2:
> >   (Tvrtko)
> >    - Skip test if preemption timeout compiled out
> >    - Skip test if engine reset isn't supported
> >    - Update debug prints to be more descriptive
> > v3:
> >    - Add comment explaining test
> > 
> > Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> > ---
> >   drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
> >   1 file changed, 117 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
> > index 7f66f6d299b26..f78de99d5ae1e 100644
> > --- a/drivers/gpu/drm/i915/selftests/i915_request.c
> > +++ b/drivers/gpu/drm/i915/selftests/i915_request.c
> > @@ -782,6 +782,115 @@ static int __cancel_completed(struct intel_engine_cs *engine)
> >   	return err;
> >   }
> > +/*
> > + * Test to prove a non-preemptable request can be cancelled and a subsequent
> > + * request on the same context can successfully complete after cancallation.
> cancellation
> 

Yep.

> > + *
> > + * Testing methodology is to create non-preemptable request and submit it,
> a non-preemptible
>

Yep.

> > + * wait for spinner to start, create a NOP request and submit it, cancel the
> > + * spinner, wait for spinner to complete and verify it failed with an error,
> > + * finally wait for NOP request to complete verify it succeeded without an
> > + * error. Preemption timeout also reduced / restored so test runs in a timely
> > + * maner.
> > + */
> > +static int __cancel_reset(struct drm_i915_private *i915,
> > +			  struct intel_engine_cs *engine)
> > +{
> > +	struct intel_context *ce;
> > +	struct igt_spinner spin;
> > +	struct i915_request *rq, *nop;
> > +	unsigned long preempt_timeout_ms;
> > +	int err = 0;
> > +
> > +	if (!CONFIG_DRM_I915_PREEMPT_TIMEOUT ||
> Does this matter? The test is overriding the default anyway.
>

Yes. Execlists don't try to preempt anything if
CONFIG_DRM_I915_PREEMPT_TIMEOUT is turned off. If we wan't to avoid the
cancelation doing a full GT reset, CONFIG_DRM_I915_PREEMPT_TIMEOUT
should be turned on.
 
> > +	    !intel_has_reset_engine(engine->gt))
> > +		return 0;
> > +
> > +	preempt_timeout_ms = engine->props.preempt_timeout_ms;
> > +	engine->props.preempt_timeout_ms = 100;
> > +
> > +	if (igt_spinner_init(&spin, engine->gt))
> > +		goto out_restore;
> > +
> > +	ce = intel_context_create(engine);
> > +	if (IS_ERR(ce)) {
> > +		err = PTR_ERR(ce);
> > +		goto out_spin;
> > +	}
> > +
> > +	rq = igt_spinner_create_request(&spin, ce, MI_NOOP);
> > +	if (IS_ERR(rq)) {
> > +		err = PTR_ERR(rq);
> > +		goto out_ce;
> > +	}
> > +
> > +	pr_debug("%s: Cancelling active non-preemptable request\n",
> > +		 engine->name);
> > +	i915_request_get(rq);
> > +	i915_request_add(rq);
> > +	if (!igt_wait_for_spinner(&spin, rq)) {
> > +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> > +
> > +		pr_err("Failed to start spinner on %s\n", engine->name);
> > +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> > +		err = -ETIME;
> > +		goto out_rq;
> > +	}
> > +
> > +	nop = intel_context_create_request(ce);
> > +	if (IS_ERR(nop))
> > +		goto out_nop;
> Should be out_rq?
>

Yes, it should.

Matt

> John.
> 
> 
> > +	i915_request_get(nop);
> > +	i915_request_add(nop);
> > +
> > +	i915_request_cancel(rq, -EINTR);
> > +
> > +	if (i915_request_wait(rq, 0, HZ) < 0) {
> > +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> > +
> > +		pr_err("%s: Failed to cancel hung request\n", engine->name);
> > +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> > +		err = -ETIME;
> > +		goto out_nop;
> > +	}
> > +
> > +	if (rq->fence.error != -EINTR) {
> > +		pr_err("%s: fence not cancelled (%u)\n",
> > +		       engine->name, rq->fence.error);
> > +		err = -EINVAL;
> > +		goto out_nop;
> > +	}
> > +
> > +	if (i915_request_wait(nop, 0, HZ) < 0) {
> > +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> > +
> > +		pr_err("%s: Failed to complete nop request\n", engine->name);
> > +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> > +		err = -ETIME;
> > +		goto out_nop;
> > +	}
> > +
> > +	if (nop->fence.error != 0) {
> > +		pr_err("%s: Nop request errored (%u)\n",
> > +		       engine->name, nop->fence.error);
> > +		err = -EINVAL;
> > +	}
> > +
> > +out_nop:
> > +	i915_request_put(nop);
> > +out_rq:
> > +	i915_request_put(rq);
> > +out_ce:
> > +	intel_context_put(ce);
> > +out_spin:
> > +	igt_spinner_fini(&spin);
> > +out_restore:
> > +	engine->props.preempt_timeout_ms = preempt_timeout_ms;
> > +	if (err)
> > +		pr_err("%s: %s error %d\n", __func__, engine->name, err);
> > +	return err;
> > +}
> > +
> >   static int live_cancel_request(void *arg)
> >   {
> >   	struct drm_i915_private *i915 = arg;
> > @@ -814,6 +923,14 @@ static int live_cancel_request(void *arg)
> >   			return err;
> >   		if (err2)
> >   			return err2;
> > +
> > +		/* Expects reset so call outside of igt_live_test_* */
> > +		err = __cancel_reset(i915, engine);
> > +		if (err)
> > +			return err;
> > +
> > +		if (igt_flush_test(i915))
> > +			return -EIO;
> >   	}
> >   	return 0;
> 

Re: [PATCH 1/2] drm/i915/selftests: Add a cancel request selftest that triggers a reset

[John Harrison]

On 1/13/2022 09:34, Matthew Brost wrote:
> On Thu, Jan 13, 2022 at 09:33:12AM -0800, John Harrison wrote:
>> On 1/11/2022 15:11, Matthew Brost wrote:
>>> Add a cancel request selftest that results in an engine reset to cancel
>>> the request as it is non-preemptable. Also insert a NOP request after
>>> the cancelled request and confirm that it completes successfully.
>>>
>>> v2:
>>>    (Tvrtko)
>>>     - Skip test if preemption timeout compiled out
>>>     - Skip test if engine reset isn't supported
>>>     - Update debug prints to be more descriptive
>>> v3:
>>>     - Add comment explaining test
>>>
>>> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>>> ---
>>>    drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
>>>    1 file changed, 117 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
>>> index 7f66f6d299b26..f78de99d5ae1e 100644
>>> --- a/drivers/gpu/drm/i915/selftests/i915_request.c
>>> +++ b/drivers/gpu/drm/i915/selftests/i915_request.c
>>> @@ -782,6 +782,115 @@ static int __cancel_completed(struct intel_engine_cs *engine)
>>>    	return err;
>>>    }
>>> +/*
>>> + * Test to prove a non-preemptable request can be cancelled and a subsequent
>>> + * request on the same context can successfully complete after cancallation.
>> cancellation
>>
> Yep.
>
>>> + *
>>> + * Testing methodology is to create non-preemptable request and submit it,
>> a non-preemptible
>>
> Yep.
>
>>> + * wait for spinner to start, create a NOP request and submit it, cancel the
>>> + * spinner, wait for spinner to complete and verify it failed with an error,
>>> + * finally wait for NOP request to complete verify it succeeded without an
>>> + * error. Preemption timeout also reduced / restored so test runs in a timely
>>> + * maner.
>>> + */
>>> +static int __cancel_reset(struct drm_i915_private *i915,
>>> +			  struct intel_engine_cs *engine)
>>> +{
>>> +	struct intel_context *ce;
>>> +	struct igt_spinner spin;
>>> +	struct i915_request *rq, *nop;
>>> +	unsigned long preempt_timeout_ms;
>>> +	int err = 0;
>>> +
>>> +	if (!CONFIG_DRM_I915_PREEMPT_TIMEOUT ||
>> Does this matter? The test is overriding the default anyway.
>>
> Yes. Execlists don't try to preempt anything if
> CONFIG_DRM_I915_PREEMPT_TIMEOUT is turned off. If we wan't to avoid the
> cancelation doing a full GT reset, CONFIG_DRM_I915_PREEMPT_TIMEOUT
> should be turned on.
>   
Hmm, I would read that as a bug. The description for the config 
parameter is:
           "This is adjustable via
           /sys/class/drm/card?/engine/*/preempt_timeout_ms

           May be 0 to disable the timeout.

           The compiled in default may get overridden at driver probe 
time on
           certain platforms and certain engines which will be reflected 
in the
           sysfs control."

I would take that as meaning that even if the compiled in default is 
zero, the user or even the i915 driver itself could override that at 
runtime and enable pre-emption again. So having any code use this as a 
flag is broken. Indeed, any code other than 
'engine->default_preempt_timeout = CONFIG_PREEMPT_TIMEOUT' is broken, IMHO.

But maybe that's for a different patch. If the driver is already 
behaving badly and doing the correct thing here will actually cause test 
failures then you can't really do much other than follow the existing 
bad behaviour.

John.


>>> +	    !intel_has_reset_engine(engine->gt))
>>> +		return 0;
>>> +
>>> +	preempt_timeout_ms = engine->props.preempt_timeout_ms;
>>> +	engine->props.preempt_timeout_ms = 100;
>>> +
>>> +	if (igt_spinner_init(&spin, engine->gt))
>>> +		goto out_restore;
>>> +
>>> +	ce = intel_context_create(engine);
>>> +	if (IS_ERR(ce)) {
>>> +		err = PTR_ERR(ce);
>>> +		goto out_spin;
>>> +	}
>>> +
>>> +	rq = igt_spinner_create_request(&spin, ce, MI_NOOP);
>>> +	if (IS_ERR(rq)) {
>>> +		err = PTR_ERR(rq);
>>> +		goto out_ce;
>>> +	}
>>> +
>>> +	pr_debug("%s: Cancelling active non-preemptable request\n",
>>> +		 engine->name);
>>> +	i915_request_get(rq);
>>> +	i915_request_add(rq);
>>> +	if (!igt_wait_for_spinner(&spin, rq)) {
>>> +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
>>> +
>>> +		pr_err("Failed to start spinner on %s\n", engine->name);
>>> +		intel_engine_dump(engine, &p, "%s\n", engine->name);
>>> +		err = -ETIME;
>>> +		goto out_rq;
>>> +	}
>>> +
>>> +	nop = intel_context_create_request(ce);
>>> +	if (IS_ERR(nop))
>>> +		goto out_nop;
>> Should be out_rq?
>>
> Yes, it should.
>
> Matt
>
>> John.
>>
>>
>>> +	i915_request_get(nop);
>>> +	i915_request_add(nop);
>>> +
>>> +	i915_request_cancel(rq, -EINTR);
>>> +
>>> +	if (i915_request_wait(rq, 0, HZ) < 0) {
>>> +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
>>> +
>>> +		pr_err("%s: Failed to cancel hung request\n", engine->name);
>>> +		intel_engine_dump(engine, &p, "%s\n", engine->name);
>>> +		err = -ETIME;
>>> +		goto out_nop;
>>> +	}
>>> +
>>> +	if (rq->fence.error != -EINTR) {
>>> +		pr_err("%s: fence not cancelled (%u)\n",
>>> +		       engine->name, rq->fence.error);
>>> +		err = -EINVAL;
>>> +		goto out_nop;
>>> +	}
>>> +
>>> +	if (i915_request_wait(nop, 0, HZ) < 0) {
>>> +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
>>> +
>>> +		pr_err("%s: Failed to complete nop request\n", engine->name);
>>> +		intel_engine_dump(engine, &p, "%s\n", engine->name);
>>> +		err = -ETIME;
>>> +		goto out_nop;
>>> +	}
>>> +
>>> +	if (nop->fence.error != 0) {
>>> +		pr_err("%s: Nop request errored (%u)\n",
>>> +		       engine->name, nop->fence.error);
>>> +		err = -EINVAL;
>>> +	}
>>> +
>>> +out_nop:
>>> +	i915_request_put(nop);
>>> +out_rq:
>>> +	i915_request_put(rq);
>>> +out_ce:
>>> +	intel_context_put(ce);
>>> +out_spin:
>>> +	igt_spinner_fini(&spin);
>>> +out_restore:
>>> +	engine->props.preempt_timeout_ms = preempt_timeout_ms;
>>> +	if (err)
>>> +		pr_err("%s: %s error %d\n", __func__, engine->name, err);
>>> +	return err;
>>> +}
>>> +
>>>    static int live_cancel_request(void *arg)
>>>    {
>>>    	struct drm_i915_private *i915 = arg;
>>> @@ -814,6 +923,14 @@ static int live_cancel_request(void *arg)
>>>    			return err;
>>>    		if (err2)
>>>    			return err2;
>>> +
>>> +		/* Expects reset so call outside of igt_live_test_* */
>>> +		err = __cancel_reset(i915, engine);
>>> +		if (err)
>>> +			return err;
>>> +
>>> +		if (igt_flush_test(i915))
>>> +			return -EIO;
>>>    	}
>>>    	return 0;

Re: [PATCH 1/2] drm/i915/selftests: Add a cancel request selftest that triggers a reset

[Matthew Brost]

On Thu, Jan 13, 2022 at 09:59:35AM -0800, John Harrison wrote:
> On 1/13/2022 09:34, Matthew Brost wrote:
> > On Thu, Jan 13, 2022 at 09:33:12AM -0800, John Harrison wrote:
> > > On 1/11/2022 15:11, Matthew Brost wrote:
> > > > Add a cancel request selftest that results in an engine reset to cancel
> > > > the request as it is non-preemptable. Also insert a NOP request after
> > > > the cancelled request and confirm that it completes successfully.
> > > > 
> > > > v2:
> > > >    (Tvrtko)
> > > >     - Skip test if preemption timeout compiled out
> > > >     - Skip test if engine reset isn't supported
> > > >     - Update debug prints to be more descriptive
> > > > v3:
> > > >     - Add comment explaining test
> > > > 
> > > > Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> > > > ---
> > > >    drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
> > > >    1 file changed, 117 insertions(+)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
> > > > index 7f66f6d299b26..f78de99d5ae1e 100644
> > > > --- a/drivers/gpu/drm/i915/selftests/i915_request.c
> > > > +++ b/drivers/gpu/drm/i915/selftests/i915_request.c
> > > > @@ -782,6 +782,115 @@ static int __cancel_completed(struct intel_engine_cs *engine)
> > > >    	return err;
> > > >    }
> > > > +/*
> > > > + * Test to prove a non-preemptable request can be cancelled and a subsequent
> > > > + * request on the same context can successfully complete after cancallation.
> > > cancellation
> > > 
> > Yep.
> > 
> > > > + *
> > > > + * Testing methodology is to create non-preemptable request and submit it,
> > > a non-preemptible
> > > 
> > Yep.
> > 
> > > > + * wait for spinner to start, create a NOP request and submit it, cancel the
> > > > + * spinner, wait for spinner to complete and verify it failed with an error,
> > > > + * finally wait for NOP request to complete verify it succeeded without an
> > > > + * error. Preemption timeout also reduced / restored so test runs in a timely
> > > > + * maner.
> > > > + */
> > > > +static int __cancel_reset(struct drm_i915_private *i915,
> > > > +			  struct intel_engine_cs *engine)
> > > > +{
> > > > +	struct intel_context *ce;
> > > > +	struct igt_spinner spin;
> > > > +	struct i915_request *rq, *nop;
> > > > +	unsigned long preempt_timeout_ms;
> > > > +	int err = 0;
> > > > +
> > > > +	if (!CONFIG_DRM_I915_PREEMPT_TIMEOUT ||
> > > Does this matter? The test is overriding the default anyway.
> > > 
> > Yes. Execlists don't try to preempt anything if
> > CONFIG_DRM_I915_PREEMPT_TIMEOUT is turned off. If we wan't to avoid the
> > cancelation doing a full GT reset, CONFIG_DRM_I915_PREEMPT_TIMEOUT
> > should be turned on.
> Hmm, I would read that as a bug. The description for the config parameter
> is:
>           "This is adjustable via
>           /sys/class/drm/card?/engine/*/preempt_timeout_ms
> 
>           May be 0 to disable the timeout.
> 
>           The compiled in default may get overridden at driver probe time on
>           certain platforms and certain engines which will be reflected in
> the
>           sysfs control."
> 
> I would take that as meaning that even if the compiled in default is zero,
> the user or even the i915 driver itself could override that at runtime and
> enable pre-emption again. So having any code use this as a flag is broken.
> Indeed, any code other than 'engine->default_preempt_timeout =
> CONFIG_PREEMPT_TIMEOUT' is broken, IMHO.
> 

Can't really argue against you here.

> But maybe that's for a different patch. If the driver is already behaving
> badly and doing the correct thing here will actually cause test failures
> then you can't really do much other than follow the existing bad behaviour.
>

Yea, agree it is out of scope this patch / series. We can cleanup the
execlists code in a follow up patch if needed + loop in an execlists
expert for a reviewer. Maybe there is a unknown reason that code is
doing this?

Matt

> John.
> 
> 
> > > > +	    !intel_has_reset_engine(engine->gt))
> > > > +		return 0;
> > > > +
> > > > +	preempt_timeout_ms = engine->props.preempt_timeout_ms;
> > > > +	engine->props.preempt_timeout_ms = 100;
> > > > +
> > > > +	if (igt_spinner_init(&spin, engine->gt))
> > > > +		goto out_restore;
> > > > +
> > > > +	ce = intel_context_create(engine);
> > > > +	if (IS_ERR(ce)) {
> > > > +		err = PTR_ERR(ce);
> > > > +		goto out_spin;
> > > > +	}
> > > > +
> > > > +	rq = igt_spinner_create_request(&spin, ce, MI_NOOP);
> > > > +	if (IS_ERR(rq)) {
> > > > +		err = PTR_ERR(rq);
> > > > +		goto out_ce;
> > > > +	}
> > > > +
> > > > +	pr_debug("%s: Cancelling active non-preemptable request\n",
> > > > +		 engine->name);
> > > > +	i915_request_get(rq);
> > > > +	i915_request_add(rq);
> > > > +	if (!igt_wait_for_spinner(&spin, rq)) {
> > > > +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> > > > +
> > > > +		pr_err("Failed to start spinner on %s\n", engine->name);
> > > > +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> > > > +		err = -ETIME;
> > > > +		goto out_rq;
> > > > +	}
> > > > +
> > > > +	nop = intel_context_create_request(ce);
> > > > +	if (IS_ERR(nop))
> > > > +		goto out_nop;
> > > Should be out_rq?
> > > 
> > Yes, it should.
> > 
> > Matt
> > 
> > > John.
> > > 
> > > 
> > > > +	i915_request_get(nop);
> > > > +	i915_request_add(nop);
> > > > +
> > > > +	i915_request_cancel(rq, -EINTR);
> > > > +
> > > > +	if (i915_request_wait(rq, 0, HZ) < 0) {
> > > > +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> > > > +
> > > > +		pr_err("%s: Failed to cancel hung request\n", engine->name);
> > > > +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> > > > +		err = -ETIME;
> > > > +		goto out_nop;
> > > > +	}
> > > > +
> > > > +	if (rq->fence.error != -EINTR) {
> > > > +		pr_err("%s: fence not cancelled (%u)\n",
> > > > +		       engine->name, rq->fence.error);
> > > > +		err = -EINVAL;
> > > > +		goto out_nop;
> > > > +	}
> > > > +
> > > > +	if (i915_request_wait(nop, 0, HZ) < 0) {
> > > > +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> > > > +
> > > > +		pr_err("%s: Failed to complete nop request\n", engine->name);
> > > > +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> > > > +		err = -ETIME;
> > > > +		goto out_nop;
> > > > +	}
> > > > +
> > > > +	if (nop->fence.error != 0) {
> > > > +		pr_err("%s: Nop request errored (%u)\n",
> > > > +		       engine->name, nop->fence.error);
> > > > +		err = -EINVAL;
> > > > +	}
> > > > +
> > > > +out_nop:
> > > > +	i915_request_put(nop);
> > > > +out_rq:
> > > > +	i915_request_put(rq);
> > > > +out_ce:
> > > > +	intel_context_put(ce);
> > > > +out_spin:
> > > > +	igt_spinner_fini(&spin);
> > > > +out_restore:
> > > > +	engine->props.preempt_timeout_ms = preempt_timeout_ms;
> > > > +	if (err)
> > > > +		pr_err("%s: %s error %d\n", __func__, engine->name, err);
> > > > +	return err;
> > > > +}
> > > > +
> > > >    static int live_cancel_request(void *arg)
> > > >    {
> > > >    	struct drm_i915_private *i915 = arg;
> > > > @@ -814,6 +923,14 @@ static int live_cancel_request(void *arg)
> > > >    			return err;
> > > >    		if (err2)
> > > >    			return err2;
> > > > +
> > > > +		/* Expects reset so call outside of igt_live_test_* */
> > > > +		err = __cancel_reset(i915, engine);
> > > > +		if (err)
> > > > +			return err;
> > > > +
> > > > +		if (igt_flush_test(i915))
> > > > +			return -EIO;
> > > >    	}
> > > >    	return 0;
> 

[PATCH 2/2] drm/i915/guc: Remove hacks for reset and schedule disable G2H being received out of order

[Matthew Brost]

In the i915 there are several hacks in place to make request cancelation
work with an old version of the GuC which delivered the G2H indicating
schedule disable is done before G2H indicating a context reset. Version
69 fixes this, so we can remove these hacks.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
 .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 30 ++-----------------
 1 file changed, 2 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 23a40f10d376d..3918f1be114fa 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -1533,7 +1533,6 @@ static void __guc_reset_context(struct intel_context *ce, bool stalled)
 	unsigned long flags;
 	u32 head;
 	int i, number_children = ce->parallel.number_children;
-	bool skip = false;
 	struct intel_context *parent = ce;
 
 	GEM_BUG_ON(intel_context_is_child(ce));
@@ -1544,23 +1543,10 @@ static void __guc_reset_context(struct intel_context *ce, bool stalled)
 	 * GuC will implicitly mark the context as non-schedulable when it sends
 	 * the reset notification. Make sure our state reflects this change. The
 	 * context will be marked enabled on resubmission.
-	 *
-	 * XXX: If the context is reset as a result of the request cancellation
-	 * this G2H is received after the schedule disable complete G2H which is
-	 * wrong as this creates a race between the request cancellation code
-	 * re-submitting the context and this G2H handler. This is a bug in the
-	 * GuC but can be worked around in the meantime but converting this to a
-	 * NOP if a pending enable is in flight as this indicates that a request
-	 * cancellation has occurred.
 	 */
 	spin_lock_irqsave(&ce->guc_state.lock, flags);
-	if (likely(!context_pending_enable(ce)))
-		clr_context_enabled(ce);
-	else
-		skip = true;
+	clr_context_enabled(ce);
 	spin_unlock_irqrestore(&ce->guc_state.lock, flags);
-	if (unlikely(skip))
-		goto out_put;
 
 	/*
 	 * For each context in the relationship find the hanging request
@@ -1592,7 +1578,6 @@ static void __guc_reset_context(struct intel_context *ce, bool stalled)
 	}
 
 	__unwind_incomplete_requests(parent);
-out_put:
 	intel_context_put(parent);
 }
 
@@ -2531,12 +2516,6 @@ static void guc_context_cancel_request(struct intel_context *ce,
 					true);
 		}
 
-		/*
-		 * XXX: Racey if context is reset, see comment in
-		 * __guc_reset_context().
-		 */
-		flush_work(&ce_to_guc(ce)->ct.requests.worker);
-
 		guc_context_unblock(block_context);
 		intel_context_put(ce);
 	}
@@ -3971,12 +3950,7 @@ static void guc_handle_context_reset(struct intel_guc *guc,
 {
 	trace_intel_context_reset(ce);
 
-	/*
-	 * XXX: Racey if request cancellation has occurred, see comment in
-	 * __guc_reset_context().
-	 */
-	if (likely(!intel_context_is_banned(ce) &&
-		   !context_blocked(ce))) {
+	if (likely(!intel_context_is_banned(ce))) {
 		capture_error_state(guc, ce);
 		guc_context_replay(ce);
 	} else {
-- 
2.34.1

Re: [PATCH 2/2] drm/i915/guc: Remove hacks for reset and schedule disable G2H being received out of order

[John Harrison]

On 1/11/2022 15:11, Matthew Brost wrote:
> In the i915 there are several hacks in place to make request cancelation
> work with an old version of the GuC which delivered the G2H indicating
> schedule disable is done before G2H indicating a context reset. Version
> 69 fixes this, so we can remove these hacks.
>
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>

> ---
>   .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 30 ++-----------------
>   1 file changed, 2 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> index 23a40f10d376d..3918f1be114fa 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -1533,7 +1533,6 @@ static void __guc_reset_context(struct intel_context *ce, bool stalled)
>   	unsigned long flags;
>   	u32 head;
>   	int i, number_children = ce->parallel.number_children;
> -	bool skip = false;
>   	struct intel_context *parent = ce;
>   
>   	GEM_BUG_ON(intel_context_is_child(ce));
> @@ -1544,23 +1543,10 @@ static void __guc_reset_context(struct intel_context *ce, bool stalled)
>   	 * GuC will implicitly mark the context as non-schedulable when it sends
>   	 * the reset notification. Make sure our state reflects this change. The
>   	 * context will be marked enabled on resubmission.
> -	 *
> -	 * XXX: If the context is reset as a result of the request cancellation
> -	 * this G2H is received after the schedule disable complete G2H which is
> -	 * wrong as this creates a race between the request cancellation code
> -	 * re-submitting the context and this G2H handler. This is a bug in the
> -	 * GuC but can be worked around in the meantime but converting this to a
> -	 * NOP if a pending enable is in flight as this indicates that a request
> -	 * cancellation has occurred.
>   	 */
>   	spin_lock_irqsave(&ce->guc_state.lock, flags);
> -	if (likely(!context_pending_enable(ce)))
> -		clr_context_enabled(ce);
> -	else
> -		skip = true;
> +	clr_context_enabled(ce);
>   	spin_unlock_irqrestore(&ce->guc_state.lock, flags);
> -	if (unlikely(skip))
> -		goto out_put;
>   
>   	/*
>   	 * For each context in the relationship find the hanging request
> @@ -1592,7 +1578,6 @@ static void __guc_reset_context(struct intel_context *ce, bool stalled)
>   	}
>   
>   	__unwind_incomplete_requests(parent);
> -out_put:
>   	intel_context_put(parent);
>   }
>   
> @@ -2531,12 +2516,6 @@ static void guc_context_cancel_request(struct intel_context *ce,
>   					true);
>   		}
>   
> -		/*
> -		 * XXX: Racey if context is reset, see comment in
> -		 * __guc_reset_context().
> -		 */
> -		flush_work(&ce_to_guc(ce)->ct.requests.worker);
> -
>   		guc_context_unblock(block_context);
>   		intel_context_put(ce);
>   	}
> @@ -3971,12 +3950,7 @@ static void guc_handle_context_reset(struct intel_guc *guc,
>   {
>   	trace_intel_context_reset(ce);
>   
> -	/*
> -	 * XXX: Racey if request cancellation has occurred, see comment in
> -	 * __guc_reset_context().
> -	 */
> -	if (likely(!intel_context_is_banned(ce) &&
> -		   !context_blocked(ce))) {
> +	if (likely(!intel_context_is_banned(ce))) {
>   		capture_error_state(guc, ce);
>   		guc_context_replay(ce);
>   	} else {

[PATCH 0/2] Remove some hacks required for GuC 62.0.0

[Matthew Brost]

Remove a hack required because schedule disable done G2H was received
before context reset G2H in GuC firmware 62.0.0. Since we have upgraded
69.0.3, this is no longer required.

Also revive selftest which proves this works before / after change.

v2:
  - Address John Harrion's comments

Signed-off-by: Matthew Brost <matthew.brost@intel.com>

Matthew Brost (2):
  drm/i915/selftests: Add a cancel request selftest that triggers a
    reset
  drm/i915/guc: Remove hacks for reset and schedule disable G2H being
    received out of order

 .../gpu/drm/i915/gt/uc/intel_guc_submission.c |  30 +----
 drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
 2 files changed, 119 insertions(+), 28 deletions(-)

-- 
2.34.1

[PATCH 1/2] drm/i915/selftests: Add a cancel request selftest that triggers a reset

[Matthew Brost]

Add a cancel request selftest that results in an engine reset to cancel
the request as it is non-preemptable. Also insert a NOP request after
the cancelled request and confirm that it completes successfully.

v2:
 (Tvrtko)
  - Skip test if preemption timeout compiled out
  - Skip test if engine reset isn't supported
  - Update debug prints to be more descriptive
v3:
  - Add comment explaining test
v4:
 (John Harrison)
  - Fix typos in comment explaining test
  - goto out_rq is NOP creation fails

Signed-off-by: Matthew Brost <matthew.brost@intel.com>

---
 drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
 1 file changed, 117 insertions(+)
---
 drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
 1 file changed, 117 insertions(+)

diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
index 7f66f6d299b26..2a99dd7c2fe8a 100644
--- a/drivers/gpu/drm/i915/selftests/i915_request.c
+++ b/drivers/gpu/drm/i915/selftests/i915_request.c
@@ -782,6 +782,115 @@ static int __cancel_completed(struct intel_engine_cs *engine)
 	return err;
 }
 
+/*
+ * Test to prove a non-preemptable request can be cancelled and a subsequent
+ * request on the same context can successfully complete after cancellation.
+ *
+ * Testing methodology is to create a non-preemptible request and submit it,
+ * wait for spinner to start, create a NOP request and submit it, cancel the
+ * spinner, wait for spinner to complete and verify it failed with an error,
+ * finally wait for NOP request to complete verify it succeeded without an
+ * error. Preemption timeout also reduced / restored so test runs in a timely
+ * maner.
+ */
+static int __cancel_reset(struct drm_i915_private *i915,
+			  struct intel_engine_cs *engine)
+{
+	struct intel_context *ce;
+	struct igt_spinner spin;
+	struct i915_request *rq, *nop;
+	unsigned long preempt_timeout_ms;
+	int err = 0;
+
+	if (!CONFIG_DRM_I915_PREEMPT_TIMEOUT ||
+	    !intel_has_reset_engine(engine->gt))
+		return 0;
+
+	preempt_timeout_ms = engine->props.preempt_timeout_ms;
+	engine->props.preempt_timeout_ms = 100;
+
+	if (igt_spinner_init(&spin, engine->gt))
+		goto out_restore;
+
+	ce = intel_context_create(engine);
+	if (IS_ERR(ce)) {
+		err = PTR_ERR(ce);
+		goto out_spin;
+	}
+
+	rq = igt_spinner_create_request(&spin, ce, MI_NOOP);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto out_ce;
+	}
+
+	pr_debug("%s: Cancelling active non-preemptable request\n",
+		 engine->name);
+	i915_request_get(rq);
+	i915_request_add(rq);
+	if (!igt_wait_for_spinner(&spin, rq)) {
+		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+		pr_err("Failed to start spinner on %s\n", engine->name);
+		intel_engine_dump(engine, &p, "%s\n", engine->name);
+		err = -ETIME;
+		goto out_rq;
+	}
+
+	nop = intel_context_create_request(ce);
+	if (IS_ERR(nop))
+		goto out_rq;
+	i915_request_get(nop);
+	i915_request_add(nop);
+
+	i915_request_cancel(rq, -EINTR);
+
+	if (i915_request_wait(rq, 0, HZ) < 0) {
+		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+		pr_err("%s: Failed to cancel hung request\n", engine->name);
+		intel_engine_dump(engine, &p, "%s\n", engine->name);
+		err = -ETIME;
+		goto out_nop;
+	}
+
+	if (rq->fence.error != -EINTR) {
+		pr_err("%s: fence not cancelled (%u)\n",
+		       engine->name, rq->fence.error);
+		err = -EINVAL;
+		goto out_nop;
+	}
+
+	if (i915_request_wait(nop, 0, HZ) < 0) {
+		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
+
+		pr_err("%s: Failed to complete nop request\n", engine->name);
+		intel_engine_dump(engine, &p, "%s\n", engine->name);
+		err = -ETIME;
+		goto out_nop;
+	}
+
+	if (nop->fence.error != 0) {
+		pr_err("%s: Nop request errored (%u)\n",
+		       engine->name, nop->fence.error);
+		err = -EINVAL;
+	}
+
+out_nop:
+	i915_request_put(nop);
+out_rq:
+	i915_request_put(rq);
+out_ce:
+	intel_context_put(ce);
+out_spin:
+	igt_spinner_fini(&spin);
+out_restore:
+	engine->props.preempt_timeout_ms = preempt_timeout_ms;
+	if (err)
+		pr_err("%s: %s error %d\n", __func__, engine->name, err);
+	return err;
+}
+
 static int live_cancel_request(void *arg)
 {
 	struct drm_i915_private *i915 = arg;
@@ -814,6 +923,14 @@ static int live_cancel_request(void *arg)
 			return err;
 		if (err2)
 			return err2;
+
+		/* Expects reset so call outside of igt_live_test_* */
+		err = __cancel_reset(i915, engine);
+		if (err)
+			return err;
+
+		if (igt_flush_test(i915))
+			return -EIO;
 	}
 
 	return 0;
-- 
2.34.1

Re: [PATCH 1/2] drm/i915/selftests: Add a cancel request selftest that triggers a reset

[John Harrison]

On 1/13/2022 10:13, Matthew Brost wrote:
> Add a cancel request selftest that results in an engine reset to cancel
> the request as it is non-preemptable. Also insert a NOP request after
> the cancelled request and confirm that it completes successfully.
>
> v2:
>   (Tvrtko)
>    - Skip test if preemption timeout compiled out
>    - Skip test if engine reset isn't supported
>    - Update debug prints to be more descriptive
> v3:
>    - Add comment explaining test
> v4:
>   (John Harrison)
>    - Fix typos in comment explaining test
>    - goto out_rq is NOP creation fails
>
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>
> ---
>   drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
>   1 file changed, 117 insertions(+)
> ---
>   drivers/gpu/drm/i915/selftests/i915_request.c | 117 ++++++++++++++++++
>   1 file changed, 117 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
> index 7f66f6d299b26..2a99dd7c2fe8a 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_request.c
> +++ b/drivers/gpu/drm/i915/selftests/i915_request.c
> @@ -782,6 +782,115 @@ static int __cancel_completed(struct intel_engine_cs *engine)
>   	return err;
>   }
>   
> +/*
> + * Test to prove a non-preemptable request can be cancelled and a subsequent
Oops - another 'preemptible'. Maybe fix that one during merge?

Reviewed-by: John Harrison <John.C.Harrison@Intel.com>


> + * request on the same context can successfully complete after cancellation.
> + *
> + * Testing methodology is to create a non-preemptible request and submit it,
> + * wait for spinner to start, create a NOP request and submit it, cancel the
> + * spinner, wait for spinner to complete and verify it failed with an error,
> + * finally wait for NOP request to complete verify it succeeded without an
> + * error. Preemption timeout also reduced / restored so test runs in a timely
> + * maner.
> + */
> +static int __cancel_reset(struct drm_i915_private *i915,
> +			  struct intel_engine_cs *engine)
> +{
> +	struct intel_context *ce;
> +	struct igt_spinner spin;
> +	struct i915_request *rq, *nop;
> +	unsigned long preempt_timeout_ms;
> +	int err = 0;
> +
> +	if (!CONFIG_DRM_I915_PREEMPT_TIMEOUT ||
> +	    !intel_has_reset_engine(engine->gt))
> +		return 0;
> +
> +	preempt_timeout_ms = engine->props.preempt_timeout_ms;
> +	engine->props.preempt_timeout_ms = 100;
> +
> +	if (igt_spinner_init(&spin, engine->gt))
> +		goto out_restore;
> +
> +	ce = intel_context_create(engine);
> +	if (IS_ERR(ce)) {
> +		err = PTR_ERR(ce);
> +		goto out_spin;
> +	}
> +
> +	rq = igt_spinner_create_request(&spin, ce, MI_NOOP);
> +	if (IS_ERR(rq)) {
> +		err = PTR_ERR(rq);
> +		goto out_ce;
> +	}
> +
> +	pr_debug("%s: Cancelling active non-preemptable request\n",
> +		 engine->name);
> +	i915_request_get(rq);
> +	i915_request_add(rq);
> +	if (!igt_wait_for_spinner(&spin, rq)) {
> +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> +
> +		pr_err("Failed to start spinner on %s\n", engine->name);
> +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> +		err = -ETIME;
> +		goto out_rq;
> +	}
> +
> +	nop = intel_context_create_request(ce);
> +	if (IS_ERR(nop))
> +		goto out_rq;
> +	i915_request_get(nop);
> +	i915_request_add(nop);
> +
> +	i915_request_cancel(rq, -EINTR);
> +
> +	if (i915_request_wait(rq, 0, HZ) < 0) {
> +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> +
> +		pr_err("%s: Failed to cancel hung request\n", engine->name);
> +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> +		err = -ETIME;
> +		goto out_nop;
> +	}
> +
> +	if (rq->fence.error != -EINTR) {
> +		pr_err("%s: fence not cancelled (%u)\n",
> +		       engine->name, rq->fence.error);
> +		err = -EINVAL;
> +		goto out_nop;
> +	}
> +
> +	if (i915_request_wait(nop, 0, HZ) < 0) {
> +		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);
> +
> +		pr_err("%s: Failed to complete nop request\n", engine->name);
> +		intel_engine_dump(engine, &p, "%s\n", engine->name);
> +		err = -ETIME;
> +		goto out_nop;
> +	}
> +
> +	if (nop->fence.error != 0) {
> +		pr_err("%s: Nop request errored (%u)\n",
> +		       engine->name, nop->fence.error);
> +		err = -EINVAL;
> +	}
> +
> +out_nop:
> +	i915_request_put(nop);
> +out_rq:
> +	i915_request_put(rq);
> +out_ce:
> +	intel_context_put(ce);
> +out_spin:
> +	igt_spinner_fini(&spin);
> +out_restore:
> +	engine->props.preempt_timeout_ms = preempt_timeout_ms;
> +	if (err)
> +		pr_err("%s: %s error %d\n", __func__, engine->name, err);
> +	return err;
> +}
> +
>   static int live_cancel_request(void *arg)
>   {
>   	struct drm_i915_private *i915 = arg;
> @@ -814,6 +923,14 @@ static int live_cancel_request(void *arg)
>   			return err;
>   		if (err2)
>   			return err2;
> +
> +		/* Expects reset so call outside of igt_live_test_* */
> +		err = __cancel_reset(i915, engine);
> +		if (err)
> +			return err;
> +
> +		if (igt_flush_test(i915))
> +			return -EIO;
>   	}
>   
>   	return 0;