Messages in this thread | | | Date | Thu, 19 Oct 2006 19:41:57 -0700 | From | Greg KH <> | Subject | Re: pci_fixup_video change blows up on sparc64 |
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On Thu, Oct 19, 2006 at 03:32:28PM -0700, David Miller wrote: > From: <eiichiro.oiwa.nm@hitachi.com> > Date: Thu, 19 Oct 2006 19:49:26 +0900 > > > The "0xc0000" is a physical address. The BAR (PCI base address) is also > > a physcail address. There are no difference. > > Your assertion that the BAR is a physical address is very platform > specific. It may be a "physical address in PCI bus space", but > that has no relation to the first argument passed to ioremap() > which is defined in a completely different way. > > On many platforms, the BAR of PCI devices are translated into an > appropriate "ioremap() cookie" in the struct pci_dev resource[] array > entries, so that they can be used properly as the first argument to > ioremap(). Only address cookies properly setup by the platform may be > legally passed into ioremap() as the first argument. No such setups > are being made on this raw 0xc0000 address. > > So, as you can see, I/O port and I/O memory space work differently on > different platforms and this abstraction of the first argument to > ioremap() is how we provide support for such differences. > > If you try to access 0xc0000 via ioremap() on sparc64, it is going to > try and access that area non-cacheable which, since 0xc0000 is > physical RAM, will result in a BUS ERROR and a crash. > > This physical location might be the area for the video ROM on x86, > x86_64, and perhaps even IA64, but it certainly is not used this way > on sparc64 systems. > > I really would like to see this regression fixed, or at the very > least this code protected by X86, X86_64, IA64 conditionals.
I agree. Eiichiro, care to send me an patch to fix this somehow? Or do you want me to just revert it?
thanks,
greg k-h - 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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