Message ID | 4C0CF0DC.7060901@kernel.org |
---|---|
State | Not Applicable |
Delegated to: | David Miller |
Headers | show |
On 06/07/2010 09:15 AM, Tejun Heo wrote: > Commit 96d60303fd (ahci: Turn off DMA engines when there's no device) > implemented stopping DMA engines on empty ports but it used single > sampling of status registers to determine device presence which led to > disabling of DMA engines on occupied ports. Do it after all EH > actions are complete using device presence state determined by EH. > This avoids spurious disabling of DMA engines and simplifies the code. > > Signed-off-by: Tejun Heo<tj@kernel.org> > Tested-by: Marc Dionne<marc.c.dionne@gmail.com> > Cc: Matthew Garrett<mjg@redhat.com> > Cc: Robert Hancock<hancockrwd@gmail.com> > --- > drivers/ata/libahci.c | 21 +++------------------ > 1 file changed, 3 insertions(+), 18 deletions(-) applied -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index 1984a6e..261f86d 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -541,29 +541,11 @@ static int ahci_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val) return -EINVAL; } -static int ahci_is_device_present(void __iomem *port_mmio) -{ - u8 status = readl(port_mmio + PORT_TFDATA) & 0xff; - - /* Make sure PxTFD.STS.BSY and PxTFD.STS.DRQ are 0 */ - if (status & (ATA_BUSY | ATA_DRQ)) - return 0; - - /* Make sure PxSSTS.DET is 3h */ - status = readl(port_mmio + PORT_SCR_STAT) & 0xf; - if (status != 3) - return 0; - return 1; -} - void ahci_start_engine(struct ata_port *ap) { void __iomem *port_mmio = ahci_port_base(ap); u32 tmp; - if (!ahci_is_device_present(port_mmio)) - return; - /* start DMA */ tmp = readl(port_mmio + PORT_CMD); tmp |= PORT_CMD_START; @@ -1892,6 +1874,9 @@ static void ahci_error_handler(struct ata_port *ap) } sata_pmp_error_handler(ap); + + if (!ata_dev_enabled(ap->link.device)) + ahci_stop_engine(ap); } static void ahci_post_internal_cmd(struct ata_queued_cmd *qc)