From a7eec9c2d5f8725340da03c5509bf04980a03072 Mon Sep 17 00:00:00 2001 From: Andy Walls Date: Sat, 10 Jan 2009 16:04:45 -0500 Subject: saa7134: Prevent Oops due to stale IRQ status when enabling interrupts From: Andy Walls 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 Priority: normal Signed-off-by: Andy Walls --- linux/drivers/media/video/saa7134/saa7134-core.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'linux/drivers/media/video/saa7134') diff --git a/linux/drivers/media/video/saa7134/saa7134-core.c b/linux/drivers/media/video/saa7134/saa7134-core.c index 2e9a015e9..624ac4537 100644 --- a/linux/drivers/media/video/saa7134/saa7134-core.c +++ b/linux/drivers/media/video/saa7134/saa7134-core.c @@ -721,6 +721,10 @@ 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); -- cgit v1.2.3