From: Andy Walls Date: Sat, 10 Jan 2009 21:04:45 +0000 (-0300) Subject: V4L/DVB (10219): saa7134: Prevent Oops due to stale IRQ status when enabling interrupts X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=7ef5e025535ee220d7ba45dcd82f05ddce8c3e4c;p=linux-2.6-omap-h63xx.git 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 Signed-off-by: Andy Walls Signed-off-by: Mauro Carvalho Chehab --- 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);