diff mbox

[Nouveau,09/17] drm/radeon: use common fence implementation for fences

Message ID 53CFB5C2.7060207@canonical.com (mailing list archive)
State New, archived
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Commit Message

Maarten Lankhorst July 23, 2014, 1:16 p.m. UTC
op 23-07-14 14:36, Christian König schreef:
> Am 23.07.2014 12:52, schrieb Daniel Vetter:
>> On Wed, Jul 23, 2014 at 12:13 PM, Christian König
>> <christian.koenig@amd.com> wrote:
>>>> And the dma-buf would still have fences belonging to both drivers, and it
>>>> would still call from outside the driver.
>>>
>>> Calling from outside the driver is fine as long as the driver can do
>>> everything necessary to complete it's work and isn't forced into any ugly
>>> hacks and things that are not 100% reliable.
>>>
>>> So I don't see much other approach as integrating recovery code for not
>>> firing interrupts and some kind of lockup handling into the fence code as
>>> well.
>> That approach doesn't really work at that well since every driver has
>> it's own reset semantics. And we're trying to move away from global
>> reset to fine-grained reset. So stop-the-world reset is out of
>> fashion, at least for i915. As you said, reset is normal in gpus and
>> we're trying to make reset less invasive. I really don't see a point
>> in imposing a reset scheme upon all drivers and I think you have about
>> as much motivation to convert radeon to the scheme used by i915 as
>> I'll have for converting to the one used by radeon. If it would fit at
>> all.
> Oh my! No, I didn't wanted to suggest any global reset infrastructure.
>
> My idea was more that the fence framework provides a fence->process_signaling callback that is periodically called after enable_signaling is called to trigger manual signal processing in the driver.
>
> This would both be suitable as a fallback in case of not working interrupts as well as a chance for any driver to do necessary lockup handling.
I managed to do it without needing it to be part of the interface? I'm not sure whether radeon_fence_driver_recheck needs exclusive_lock, but if so it's a small change..

Comments

Maarten Lankhorst July 23, 2014, 2:05 p.m. UTC | #1
op 23-07-14 15:16, Maarten Lankhorst schreef:
> op 23-07-14 14:36, Christian König schreef:
>> Am 23.07.2014 12:52, schrieb Daniel Vetter:
>>> On Wed, Jul 23, 2014 at 12:13 PM, Christian König
>>> <christian.koenig@amd.com> wrote:
>>>>> And the dma-buf would still have fences belonging to both drivers, and it
>>>>> would still call from outside the driver.
>>>> Calling from outside the driver is fine as long as the driver can do
>>>> everything necessary to complete it's work and isn't forced into any ugly
>>>> hacks and things that are not 100% reliable.
>>>>
>>>> So I don't see much other approach as integrating recovery code for not
>>>> firing interrupts and some kind of lockup handling into the fence code as
>>>> well.
>>> That approach doesn't really work at that well since every driver has
>>> it's own reset semantics. And we're trying to move away from global
>>> reset to fine-grained reset. So stop-the-world reset is out of
>>> fashion, at least for i915. As you said, reset is normal in gpus and
>>> we're trying to make reset less invasive. I really don't see a point
>>> in imposing a reset scheme upon all drivers and I think you have about
>>> as much motivation to convert radeon to the scheme used by i915 as
>>> I'll have for converting to the one used by radeon. If it would fit at
>>> all.
>> Oh my! No, I didn't wanted to suggest any global reset infrastructure.
>>
>> My idea was more that the fence framework provides a fence->process_signaling callback that is periodically called after enable_signaling is called to trigger manual signal processing in the driver.
>>
>> This would both be suitable as a fallback in case of not working interrupts as well as a chance for any driver to do necessary lockup handling.
> I managed to do it without needing it to be part of the interface? I'm not sure whether radeon_fence_driver_recheck needs exclusive_lock, but if so it's a small change..
>
> diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
> index 7fbfd41479f1..51b646b9c8bb 100644
> --- a/drivers/gpu/drm/radeon/radeon.h
> +++ b/drivers/gpu/drm/radeon/radeon.h
> @@ -345,6 +345,9 @@ struct radeon_fence_driver {
>  	uint64_t			sync_seq[RADEON_NUM_RINGS];
>  	atomic64_t			last_seq;
>  	bool				initialized;
> +	struct delayed_work		work;
> +	struct radeon_device *rdev;
> +	unsigned ring;
>  };
>  
>  struct radeon_fence_cb {
> diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
> index da83f36dd708..955c825946ad 100644
> --- a/drivers/gpu/drm/radeon/radeon_fence.c
> +++ b/drivers/gpu/drm/radeon/radeon_fence.c
> @@ -231,6 +231,9 @@ static bool __radeon_fence_process(struct radeon_device *rdev, int ring)
>  		}
>  	} while (atomic64_xchg(&rdev->fence_drv[ring].last_seq, seq) > seq);
>  
> +	if (!wake && last_seq < last_emitted)
> +		schedule_delayed_work(&rdev->fence_drv[ring].work, jiffies_to_msecs(10));
> +
>
When trying this: if (seq < last_emitted) is probably a better check.

~Maarten
Christian König July 24, 2014, 1:47 p.m. UTC | #2
Hi Maarten,

try to implement this as a replacement for specifying the 
RADEON_FENCE_JIFFIES_TIMEOUT on wait_event_*. And reset the timeout 
every time radeon_fence_process is called and not only when any of the 
sequences increment.

I don't have the time right now to look deeper into it or help with the 
patch, but the general approach sounds valid to me.

Regards,
Christian.

Am 23.07.2014 16:05, schrieb Maarten Lankhorst:
> op 23-07-14 15:16, Maarten Lankhorst schreef:
>> op 23-07-14 14:36, Christian König schreef:
>>> Am 23.07.2014 12:52, schrieb Daniel Vetter:
>>>> On Wed, Jul 23, 2014 at 12:13 PM, Christian König
>>>> <christian.koenig@amd.com> wrote:
>>>>>> And the dma-buf would still have fences belonging to both drivers, and it
>>>>>> would still call from outside the driver.
>>>>> Calling from outside the driver is fine as long as the driver can do
>>>>> everything necessary to complete it's work and isn't forced into any ugly
>>>>> hacks and things that are not 100% reliable.
>>>>>
>>>>> So I don't see much other approach as integrating recovery code for not
>>>>> firing interrupts and some kind of lockup handling into the fence code as
>>>>> well.
>>>> That approach doesn't really work at that well since every driver has
>>>> it's own reset semantics. And we're trying to move away from global
>>>> reset to fine-grained reset. So stop-the-world reset is out of
>>>> fashion, at least for i915. As you said, reset is normal in gpus and
>>>> we're trying to make reset less invasive. I really don't see a point
>>>> in imposing a reset scheme upon all drivers and I think you have about
>>>> as much motivation to convert radeon to the scheme used by i915 as
>>>> I'll have for converting to the one used by radeon. If it would fit at
>>>> all.
>>> Oh my! No, I didn't wanted to suggest any global reset infrastructure.
>>>
>>> My idea was more that the fence framework provides a fence->process_signaling callback that is periodically called after enable_signaling is called to trigger manual signal processing in the driver.
>>>
>>> This would both be suitable as a fallback in case of not working interrupts as well as a chance for any driver to do necessary lockup handling.
>> I managed to do it without needing it to be part of the interface? I'm not sure whether radeon_fence_driver_recheck needs exclusive_lock, but if so it's a small change..
>>
>> diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
>> index 7fbfd41479f1..51b646b9c8bb 100644
>> --- a/drivers/gpu/drm/radeon/radeon.h
>> +++ b/drivers/gpu/drm/radeon/radeon.h
>> @@ -345,6 +345,9 @@ struct radeon_fence_driver {
>>   	uint64_t			sync_seq[RADEON_NUM_RINGS];
>>   	atomic64_t			last_seq;
>>   	bool				initialized;
>> +	struct delayed_work		work;
>> +	struct radeon_device *rdev;
>> +	unsigned ring;
>>   };
>>   
>>   struct radeon_fence_cb {
>> diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
>> index da83f36dd708..955c825946ad 100644
>> --- a/drivers/gpu/drm/radeon/radeon_fence.c
>> +++ b/drivers/gpu/drm/radeon/radeon_fence.c
>> @@ -231,6 +231,9 @@ static bool __radeon_fence_process(struct radeon_device *rdev, int ring)
>>   		}
>>   	} while (atomic64_xchg(&rdev->fence_drv[ring].last_seq, seq) > seq);
>>   
>> +	if (!wake && last_seq < last_emitted)
>> +		schedule_delayed_work(&rdev->fence_drv[ring].work, jiffies_to_msecs(10));
>> +
>>
> When trying this: if (seq < last_emitted) is probably a better check.
>
> ~Maarten
>
diff mbox

Patch

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 7fbfd41479f1..51b646b9c8bb 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -345,6 +345,9 @@  struct radeon_fence_driver {
 	uint64_t			sync_seq[RADEON_NUM_RINGS];
 	atomic64_t			last_seq;
 	bool				initialized;
+	struct delayed_work		work;
+	struct radeon_device *rdev;
+	unsigned ring;
 };
 
 struct radeon_fence_cb {
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index da83f36dd708..955c825946ad 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -231,6 +231,9 @@  static bool __radeon_fence_process(struct radeon_device *rdev, int ring)
 		}
 	} while (atomic64_xchg(&rdev->fence_drv[ring].last_seq, seq) > seq);
 
+	if (!wake && last_seq < last_emitted)
+		schedule_delayed_work(&rdev->fence_drv[ring].work, jiffies_to_msecs(10));
+
 	return wake;
 }
 
@@ -815,6 +818,14 @@  int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
 	return 0;
 }
 
+static void radeon_fence_driver_recheck(struct work_struct *work)
+{
+	struct radeon_fence_driver *drv = container_of(work, struct radeon_fence_driver, work.work);
+
+	DRM_ERROR("omg, working!\n");
+	radeon_fence_process(drv->rdev, drv->ring);
+}
+
 /**
  * radeon_fence_driver_init_ring - init the fence driver
  * for the requested ring.
@@ -836,6 +847,10 @@  static void radeon_fence_driver_init_ring(struct radeon_device *rdev, int ring)
 		rdev->fence_drv[ring].sync_seq[i] = 0;
 	atomic64_set(&rdev->fence_drv[ring].last_seq, 0);
 	rdev->fence_drv[ring].initialized = false;
+
+	rdev->fence_drv[ring].ring = ring;
+	rdev->fence_drv[ring].rdev = rdev;
+	INIT_DELAYED_WORK(&rdev->fence_drv[ring].work, radeon_fence_driver_recheck);
 }
 
 /**
@@ -880,6 +895,7 @@  void radeon_fence_driver_fini(struct radeon_device *rdev)
 	for (ring = 0; ring < RADEON_NUM_RINGS; ring++) {
 		if (!rdev->fence_drv[ring].initialized)
 			continue;
+		cancel_delayed_work_sync(&rdev->fence_drv[ring].work);
 		r = radeon_fence_wait_empty(rdev, ring);
 		if (r) {
 			/* no need to trigger GPU reset as we are unloading */
diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index 16807afab362..85391ddd3ce9 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -331,7 +331,7 @@  void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev, int ring)
 {
 	unsigned long irqflags;
 
-	if (!rdev->ddev->irq_enabled)
+//	if (!rdev->ddev->irq_enabled)
 		return;
 
 	if (atomic_inc_return(&rdev->irq.ring_int[ring]) == 1) {
@@ -355,7 +355,7 @@  void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev, int ring)
 {
 	unsigned long irqflags;
 
-	if (!rdev->ddev->irq_enabled)
+//	if (!rdev->ddev->irq_enabled)
 		return;
 
 	if (atomic_dec_and_test(&rdev->irq.ring_int[ring])) {