On Saturday 20 October 2007 07:46:24 Benjamin Herrenschmidt wrote:
>
> > I probably need to add this synchronize_irq() logic in dmfe.c too, but I probably do it later,
> > I think I am overestimating this race, since most drivers don't do dev->insuspend checks in IRQ handler.
> > Maybe even just use free_irq() after all....
>
> Most drivers are probably underestimating the race :-)
>
> free_irq() would work provided that you did the masking on chip before
> (and unmask only after request_irq on the way back in). But it's a bit
> like using a 10 tons truck to crush an ant...
Agreed.
So, I will add synchronize_irq() to both saa7134, and dmfe, the two drivers that their .suspend/.resume
routines were written by me.
I already added a synchronize_irq() plus few more fixes to the driver , but those patches are still in v4l tree.
I now has this:
saa_writel(SAA7134_IRQ1, 0);
saa_writel(SAA7134_IRQ2, 0);
saa_writel(SAA7134_MAIN_CTRL, 0);
synchronize_irq(pci_dev->irq);
dev->insuspend = 1;
and I will probably need (with the synchronize_irq patch applied)
/* Disable interrupts, DMA, and rest of the chip*/
saa_writel(SAA7134_IRQ1, 0);
saa_writel(SAA7134_IRQ2, 0);
saa_writel(SAA7134_MAIN_CTRL, 0);
dev->insuspend = 1;
synchronize_irq(pci_dev->irq);
/* ACK pending interrupts just in case*/
saa_writel(SAA7134_IRQ_REPORT,saa_readl(SAA7134_IRQ_REPORT));
......
This should be bullet-proof.
>
> Ben.
>
>
>
Best regards,
Maxim Levitsky
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