On Sun, 11 Jan 2009, Andy Walls wrote: > On Mon, 2009-01-12 at 00:54 +0100, hermann pitton wrote: > > Am Samstag, den 10.01.2009, 22:05 -0500 schrieb Andy Walls: > > > On Sun, 2009-01-11 at 03:32 +0100, hermann pitton wrote: > > > > Am Samstag, den 10.01.2009, 07:37 -0500 schrieb Andy Walls: > > > > > On Sat, 2009-01-10 at 13:02 +0100, Marcin Slusarz wrote: > > > > > > On Fri, Jan 09, 2009 at 09:48:07PM -0500, Andy Walls wrote: > > > > > > > but not clearing the state of SAA7134_IRQ_REPORT, maybe something like > > > > > > > this (I don't have a SAA7134 datasheet): > > > > > > > > > > > > > > saa_writel(SAA7134_IRQ_REPORT, 0xffffffff); > > > > > > > > > > > > > > So when saa7134_initdev() calls request_irq(..., saa7134_irq, > > > > > > > IRQF_SHARED | IRQF_DISABLED, ...), it gets an IRQ that is shared with > > > > > > > another device. Keep in mind that PCI writes are posted, so 'writel(...);request_irq(...);' might result in the irq being requested (which only involves the CPU and kernel) before the device receives and processes the write (which involves the CPU, pci bridge(s), and the saa7134 device). IMHO, a better solution is to just not request the irq until the driver is read to handle interrupts. That seems a lot safer than depending on the irq handler not doing anything bad if it's called while the driver is still initializing. > > Andy, I allowed shared interrupts on several machines with multiple > > saa713x cards and current v4l-dvb, but I'm still not able to reproduce > > the oops. So can't try the fix. Who has the oops and can try? What you need to have is the saa713x sharing an interrupt with a different device which generates a lot of interrupts while the saa713x driver is being loaded. Even then it's a race and isn't going to happen every time. > So "dev->input" is NULL when saa7134-tvaudio.c:mute_input_7133() is > called and that is what causes the Oops. It was called by the > saa7134_irq() handler trying to take action, shortly after request_irq() > was called. Can you think of why this would happen? I have no doubt that the original idea that SAA7134_IRQ_REPORT isn't clear when the driver loads is correct. Why shouldn't the bits be set? And if they are, we should see an Oops that looks exactly like this one. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
