diff options
Diffstat (limited to 'debian/patches-rt/0028-drm-i915-gt-Queue-and-wait-for-the-irq_work-item.patch')
| -rw-r--r-- | debian/patches-rt/0028-drm-i915-gt-Queue-and-wait-for-the-irq_work-item.patch | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/debian/patches-rt/0028-drm-i915-gt-Queue-and-wait-for-the-irq_work-item.patch b/debian/patches-rt/0028-drm-i915-gt-Queue-and-wait-for-the-irq_work-item.patch new file mode 100644 index 000000000..61bd48e8b --- /dev/null +++ b/debian/patches-rt/0028-drm-i915-gt-Queue-and-wait-for-the-irq_work-item.patch @@ -0,0 +1,48 @@ +From 6dfc680fe2808eaf10a9feed7e3116df60b6032f Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Wed, 8 Sep 2021 17:18:00 +0200 +Subject: [PATCH 28/62] drm/i915/gt: Queue and wait for the irq_work item. +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.1/older/patches-6.1.69-rt21.tar.xz + +Disabling interrupts and invoking the irq_work function directly breaks +on PREEMPT_RT. +PREEMPT_RT does not invoke all irq_work from hardirq context because +some of the user have spinlock_t locking in the callback function. +These locks are then turned into a sleeping locks which can not be +acquired with disabled interrupts. + +Using irq_work_queue() has the benefit that the irqwork will be invoked +in the regular context. In general there is "no" delay between enqueuing +the callback and its invocation because the interrupt is raised right +away on architectures which support it (which includes x86). + +Use irq_work_queue() + irq_work_sync() instead invoking the callback +directly. + +Reported-by: Clark Williams <williams@redhat.com> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> +--- + drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 5 ++--- + 1 file changed, 2 insertions(+), 3 deletions(-) + +diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +index ecc990ec1b95..8d04b10681f0 100644 +--- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c ++++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +@@ -312,10 +312,9 @@ void __intel_breadcrumbs_park(struct intel_breadcrumbs *b) + /* Kick the work once more to drain the signalers, and disarm the irq */ + irq_work_sync(&b->irq_work); + while (READ_ONCE(b->irq_armed) && !atomic_read(&b->active)) { +- local_irq_disable(); +- signal_irq_work(&b->irq_work); +- local_irq_enable(); ++ irq_work_queue(&b->irq_work); + cond_resched(); ++ irq_work_sync(&b->irq_work); + } + } + +-- +2.43.0 + |