ata_device->dma_mode's initial value is zero, which is not a valid dma mode, but ata_dma_enabled will return true for this value. This patch sets dma_mode to 0xff in reset function, so that ata_dma_enabled will not return true for this case, or it will cause problem for pata_acpi. The corrsponding bugzilla page is at: https://bugzilla.kernel.org/show_bug.cgi?id=49151 Reported-by: Phillip Wood <phillip.wood@xxxxxxxxxxxxx> Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx> Tested-by: Szymon Janc <szymon@xxxxxxxxxxx> Tested-by: Dutra Julio <dutra.julio@xxxxxxxxx> Cc: <stable@xxxxxxxxxx> --- drivers/ata/libata-core.c | 1 + drivers/ata/libata-eh.c | 1 + 2 files changed, 2 insertions(+) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index f46fbd3..586362e 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2560,6 +2560,7 @@ int ata_bus_probe(struct ata_port *ap) * 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 diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index e60437c..bf039b0 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 -- 1.7.12.4 -- 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