On Mon, 2007-07-23 at 11:21 +1000, Benjamin Herrenschmidt wrote: > On Mon, 2007-07-23 at 09:55 +1000, Benjamin Herrenschmidt wrote: > > Note that with all your patches applied, it doesn't seem to auto-tune > > the speed at boot anymore and doesn't enable DMA. I can make it do so > > with hdparm -d1, in which case, for example, on this wallstreet, I get > > MDMA2 which is correct, however, it seems to also set PIO0 which it > > should set PIO4... > > One of the problems is that you do XFER_PIO + pio in > pmac_ide_set_pio_mode(), which is no good. XFER_PIO is a bad constant > name and causes that sort of confusion :-) > > Fix is to use XFER_PIO_0 + pio. I'll send a patch fixing that plus a few > other things on top of yours once I've found out what's up with DMA. > I've enable autotune, I see it sending the 0x22 command, but hdparm > still claims DMA isn't enabled. Ok, there's a combination of things here: - First, doing a set_pio from userland (hdparm -p XX) causes the kernel to disable DMA, which I think is incorrect. It's not the case with 2.6.22 from my quick tests. The problem is that ide_config_drive_speed disables DMA, but only re-enables it when setting a DMA speed. I think the whole idea of having a "current speed" is bogus here, we should have a separate current DMA speed and current PIO speed. We should be able to set the PIO timings without stopping DMA, toggling DMA is a separate affair. - For some reason, nowadays, hdparm -p /dev/hda will not autotune, but will set PIO 0 (hdparm -p 255 /dev/hda will autotune). Might be a bug in whatever hdparm version I have here. - Some userland scripts installed on debian as part of the pbbuttonsd package are doing hdaprm -p /dev/device on all IDE devices at boot. I'm investigating what's broken with hdparm Ben. - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
