On Thu, 2007-12-13 at 12:04 -0800, Jesse Barnes wrote: > > Yeah, that seems like a reasonable compromise. Though in practice > I'd > expect the full disable decode approach to work fairly well too. I > mean, if we really end up failing to allocate space for the device > with > the root drive on it, there are probably bigger issues than just > failing to get a few bytes of I/O space for it... >
The really bad scenario would be something like the Sil680 that Alan talked about setup by a BIOS that "knows" about the unused BAR when MMIO_EN is not set. If the device is behind a P2P bridge and the BIOS has set the windows of that bridge so tightly that there is no room to allocate the MMIO BAR, then a full disable/full enable would fail on a device that would otherwise work using only PIO. However, I'd be curious to see that happening in practice :-) But I think it's fair enough to do an IO only / MEM only approach. I've seen cases where IO is just not useable because of other constraints and so I expect the MEM-only case to be more common, especially on non-x86. Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
