![]() | |||||||||||||
Messages in this thread |
On Mer, 2006-03-15 at 23:00 +0100, Ingo Molnar wrote: > so my guess would be that this device doesnt do MMIO, and the PIO inb() > causes some bad BIOS-based SMM handler/emulator to trigger, which takes > 16.6 msecs. If indeed the device is not in MMIO mode, is there a way to > force it into MMIO mode, to test this theory? There is a much more reliable way to check this. Use the profiling registers to check the instruction issue count before/after the I/O and you'll know if its something like SMM or just a bus stall. I can believe the bus stall because some devices will queue a large FIFO of data for the disk and the status read may require flushing it all out. - 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: 2006-03-16 16:10 [from the cache] ©2003-2008 | |||||||||||||