Messages in this thread | | | Date | Wed, 16 Dec 2009 20:18:39 +0100 | From | Uwe Kleine-König <> | Subject | Re: [PATCH 6/7] spi/mpc8xxx: don't check platform_get_irq's return value against zero |
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Hi Anton,
On Wed, Dec 16, 2009 at 09:20:34PM +0300, Anton Vorontsov wrote: > On Wed, Dec 16, 2009 at 06:49:04PM +0100, Uwe Kleine-König wrote: > [...] > > > Noooooo... :-( > > > > > > Please revert 305b3228f9ff4d59f49e6d34a7034d44ee8ce2f0 instead, > > > and fix platforms to remap HWIRQ0 to something that is not VIRQ0. > > > > > > IRQ0 is invalid for everything that is outside of arch/*. > > > > > > http://lkml.org/lkml/2005/11/22/159 > > > http://lkml.org/lkml/2005/11/22/213 > > > http://lkml.org/lkml/2005/11/22/227 > > First note that my check is safe with both variants (e.g. it does the > > right thing independent of the error being signaled by 0 or > > -ESOMETHING.) > > > > Then arch/arm/mach-pxa/devices.c has: > > > > static struct resource pxa27x_resource_ssp3[] = { > > ... > > [1] = { > > .start = IRQ_SSP3, > > .end = IRQ_SSP3, > > .flags = IORESOURCE_IRQ, > > }, > > ... > > } > > > > with IRQ_SSP3 being zero (sometimes). The driver is implemented in > > arch/arm/mach-pxa/ssp.c and uses platform_get_irq. > > So fix this *one* driver? Implement arm-specific platform_get_irq() as > a band-aid. Or better, implement virtual irqs <-> hardware irqs mapping > for ARM. > > [...] > > I'm a bit annoyed as this is the third time[1] this month this irq0 > > discussion pops up for me. I think people see that irq0 is involved > > somehow, start wailing and stop seeing the issues being fixed. > > For this particular driver, there is NO issue whatsoever. It is > only used for PowerPC, which has VIRQ0 == invalid IRQ. And note > that there still could be HWIRQ0 on PowerPC, but it is *never* > mapped to VIRQ0. Yes, there is an issue. If the platform device doesn't have a resource specifing the irq, platform_get_irq returns -ENXIO. So in the driver (unsigned)(-ENXIO) is passed to mpc8xxx_spi_probe as (!(-ENXIO)) is false and so the error isn't catched.
> [...] > > [1] one is: > > http://thread.gmane.org/gmane.linux.kernel/924739 > > No wonder the discussion popped up. You're adding some ugly > #ifdef stuff that adds some arch-specific knowledge to a generic > code. I wouldn't argue if people objected to the arch-specific #ifdef. The arch-specific code is already in there and I don't object to just removing it. But answering that irq0 must not be used isn't helpful.
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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