![]() | |||||||||||||
Messages in this thread |
On Tue, Jun 07, 2005 at 03:59:18AM -0600, Eric W. Biederman wrote: > > *lots* of PCI devices predate PCI2.3. Possibly even the majority. > > In general generic hardware bits for disabling DMA, disabling interrupts > and the like are all advisory. With the current architecture things > will work properly even if you don't manage to disable DMA (assuming > you don't reassign IOMMU entries at least). ISTR, pSeries (IBM), some alpha, some sparc64, and parisc (64-bit) require use of the IOMMU for *any* DMA. ie IOMMU entries need to be programmed. Probably want to make a choice to ignore those arches for now or sort out how to deal with an IOMMU. > Shared interrupts are an interesting case. The simplest solution I can > think of for a crash dump capture kernel is to periodically poll > the hardware, as if all interrupts are shared. At that level > I think we could get away with ignoring all hardware interrupt sources. Yes, that's perfectly ok. We are no longer in a multitasking env. > Does anyone know of a anything that would break by always polling > the hardware? I guess there could be a problem with drivers > that don't understand shared interrupts, are there enough of those > to be an issue. PCI requires drivers support Shared IRQs. A few oddballs might be broken but I expect networking/mass storage drivers get this right. grant - 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/ | ||||||||||||
| Last update: 2005-06-07 16:24 [from the cache] ©2003-2008 | |||||||||||||