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authorAndy Walls <awalls@radix.net>2009-01-10 18:04:45 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-01-29 08:35:38 -0200
commit7ef5e025535ee220d7ba45dcd82f05ddce8c3e4c (patch)
tree6914684de5874aa3a1fd93aff3443b8f2169b961
parentcd8f894eacf13996d920fdd2aef1afc55156b191 (diff)
V4L/DVB (10219): saa7134: Prevent Oops due to stale IRQ status when enabling interrupts
When enabling a shared IRQ line, then saa7134_irq handler could be invoked before the driver had completely set up internal structures, due to a shared interrupt line firing. Clear the saa7134 interrupt status reg, before requesting the irq line, so that stale IRQ status isn't processed before the internal structures are set up. Marcin Slusarz recently brought this Oops to the attention of the v4l-dvb lists and provided an initial analysis by investigating reports found here: http://kerneloops.org/guilty.php?guilty=mute_input_7133&version=2.6.27-release&start=1802240&end=1835007&class=oops Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com> Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r--drivers/media/video/saa7134/saa7134-core.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/media/video/saa7134/saa7134-core.c b/drivers/media/video/saa7134/saa7134-core.c
index dfbe08a9ad9..99221d726ed 100644
--- a/drivers/media/video/saa7134/saa7134-core.c
+++ b/drivers/media/video/saa7134/saa7134-core.c
@@ -660,6 +660,10 @@ static int saa7134_hwinit1(struct saa7134_dev *dev)
saa_writel(SAA7134_IRQ1, 0);
saa_writel(SAA7134_IRQ2, 0);
+
+ /* Clear any stale IRQ reports */
+ saa_writel(SAA7134_IRQ_REPORT, saa_readl(SAA7134_IRQ_REPORT));
+
mutex_init(&dev->lock);
spin_lock_init(&dev->slock);