On Mon, Dec 03, 2012 at 01:22:25AM +0000, Alan Cox wrote: > On Mon, 03 Dec 2012 09:04:20 +0800 > Aaron Lu <aaron.lu@xxxxxxxxx> wrote: > > > > > ata_dma_enabled should check if device is either using multi word DMA > > or ultra DMA instead of checking 0xff, as dma_mode 0 is not a valid dma > > mode either. > > > > This patch fixes the following bug: > > https://bugzilla.kernel.org/show_bug.cgi?id=49151 > > NAK > > dma_mode should *NEVER* be zero. If it's getting set to zero you have > another bug and that needs fixing instead The ata_dev->dma_mode is initialized as zero after we allocate the ata_device structure, and we did not set this field until the set mode function. If you think it should _never_ be zero, probably my previous patch did the job: it sets ata_dev->dma_mode to 0xff in the reset operation: diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 9426423..d772d66 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -2657,6 +2657,7 @@ int ata_eh_reset(struct ata_link *link, int classify, * bus as we may be talking too fast. */ dev->pio_mode = XFER_PIO_0; + dev->dma_mode = 0xff; /* If the controller has a pio mode setup function * then use it to set the chipset to rights. Don't So do you prefer this? Thanks, Aaron > > Alan -- 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
