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From: Mike Galbraith <umgwanakikbuti@gmail.com>
Date: Sat, 27 Feb 2016 09:01:42 +0100
Subject: [PATCH] drm/i915: Don't disable interrupts on PREEMPT_RT during
atomic updates
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.9/older/patches-5.9-rt15.tar.xz
Commit
8d7849db3eab7 ("drm/i915: Make sprite updates atomic")
started disabling interrupts across atomic updates. This breaks on PREEMPT_RT
because within this section the code attempt to acquire spinlock_t locks which
are sleeping locks on PREEMPT_RT.
According to the comment the interrupts are disabled to avoid random delays and
not required for protection or synchronisation.
Don't disable interrupts on PREEMPT_RT during atomic updates.
[bigeasy: drop local locks, commit message]
Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
drivers/gpu/drm/i915/display/intel_sprite.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
--- a/drivers/gpu/drm/i915/display/intel_sprite.c
+++ b/drivers/gpu/drm/i915/display/intel_sprite.c
@@ -118,7 +118,8 @@ void intel_pipe_update_start(const struc
"PSR idle timed out 0x%x, atomic update may fail\n",
psr_status);
- local_irq_disable();
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+ local_irq_disable();
crtc->debug.min_vbl = min;
crtc->debug.max_vbl = max;
@@ -143,11 +144,13 @@ void intel_pipe_update_start(const struc
break;
}
- local_irq_enable();
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+ local_irq_enable();
timeout = schedule_timeout(timeout);
- local_irq_disable();
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+ local_irq_disable();
}
finish_wait(wq, &wait);
@@ -180,7 +183,8 @@ void intel_pipe_update_start(const struc
return;
irq_disable:
- local_irq_disable();
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+ local_irq_disable();
}
/**
@@ -218,7 +222,8 @@ void intel_pipe_update_end(struct intel_
new_crtc_state->uapi.event = NULL;
}
- local_irq_enable();
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+ local_irq_enable();
if (intel_vgpu_active(dev_priv))
return;
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