[patch 16/74] drm/i915: avoid non-atomic sysrq execution

[Greg KH]

2.6.30-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>

(cherry picked from commit b66d18ddb16603d1e1ec39cb2ff3abf3fd212180)

The sysrq functions are executed in hardirq context, so we shouldn't be
calling sleeping functions from them, like mutex_locks or memory
allocations.

Fix up the i915 sysrq handler to avoid this.

Signed-off-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
 drivers/gpu/drm/i915/intel_fb.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -857,9 +857,15 @@ void intelfb_restore(void)
 	drm_crtc_helper_set_config(&kernelfb_mode);
 }
 
+static void intelfb_restore_work_fn(struct work_struct *ignored)
+{
+	intelfb_restore();
+}
+static DECLARE_WORK(intelfb_restore_work, intelfb_restore_work_fn);
+
 static void intelfb_sysrq(int dummy1, struct tty_struct *dummy3)
 {
-        intelfb_restore();
+        schedule_work(&intelfb_restore_work);
 }
 
 static struct sysrq_key_op sysrq_intelfb_restore_op = {


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