Commit 764725a6 authored by Maarten Lankhorst's avatar Maarten Lankhorst Committed by Sasha Levin

drm/radeon: fix wait to actually occur after the signaling callback

[ Upstream commit b6610101 ]

A normal wait adds to the front of the tail. By doing something
similar to fence_default_wait the fence code can run without racing.

This is a complete fix for "panic on suspend from KDE with radeon",
and a partial fix for "Radeon: System pauses on TAHITI". On tahiti
si_irq_set needs to be fixed too, to completely flush the writes
before radeon_fence_activity is called in radeon_fence_enable_signaling.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=90741
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=90861Signed-off-by: default avatarMaarten Lankhorst <maarten.lankhorst@ubuntu.com>
Reported-by: default avatarJon Arne Jørgensen <jonjon.arnearne@gmail.com>
Reported-and-tested-by: default avatarGustaw Smolarczyk <wielkiegie@gmail.com>
Cc: stable@vger.kernel.org (v3.18+)
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
parent 6eef27b6
......@@ -1029,37 +1029,59 @@ static inline bool radeon_test_signaled(struct radeon_fence *fence)
return test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->base.flags);
}
struct radeon_wait_cb {
struct fence_cb base;
struct task_struct *task;
};
static void
radeon_fence_wait_cb(struct fence *fence, struct fence_cb *cb)
{
struct radeon_wait_cb *wait =
container_of(cb, struct radeon_wait_cb, base);
wake_up_process(wait->task);
}
static signed long radeon_fence_default_wait(struct fence *f, bool intr,
signed long t)
{
struct radeon_fence *fence = to_radeon_fence(f);
struct radeon_device *rdev = fence->rdev;
bool signaled;
struct radeon_wait_cb cb;
fence_enable_sw_signaling(&fence->base);
cb.task = current;
/*
* This function has to return -EDEADLK, but cannot hold
* exclusive_lock during the wait because some callers
* may already hold it. This means checking needs_reset without
* lock, and not fiddling with any gpu internals.
*
* The callback installed with fence_enable_sw_signaling will
* run before our wait_event_*timeout call, so we will see
* both the signaled fence and the changes to needs_reset.
*/
if (fence_add_callback(f, &cb.base, radeon_fence_wait_cb))
return t;
while (t > 0) {
if (intr)
set_current_state(TASK_INTERRUPTIBLE);
else
set_current_state(TASK_UNINTERRUPTIBLE);
/*
* radeon_test_signaled must be called after
* set_current_state to prevent a race with wake_up_process
*/
if (radeon_test_signaled(fence))
break;
if (rdev->needs_reset) {
t = -EDEADLK;
break;
}
t = schedule_timeout(t);
if (t > 0 && intr && signal_pending(current))
t = -ERESTARTSYS;
}
__set_current_state(TASK_RUNNING);
fence_remove_callback(f, &cb.base);
if (intr)
t = wait_event_interruptible_timeout(rdev->fence_queue,
((signaled = radeon_test_signaled(fence)) ||
rdev->needs_reset), t);
else
t = wait_event_timeout(rdev->fence_queue,
((signaled = radeon_test_signaled(fence)) ||
rdev->needs_reset), t);
if (t > 0 && !signaled)
return -EDEADLK;
return t;
}
......
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