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authorTejun Heo <tj@kernel.org>2010-06-07 15:15:08 +0200
committerJeff Garzik <jgarzik@redhat.com>2010-06-07 16:03:15 -0400
commit0ee719527229fa86ace8e3abccae3c2a8bbfd6db (patch)
tree7c9e76554f55af8101f38b8e3338529b66b4d275 /drivers/ata
parent7a4f876b876afb13856a79a0402f71b9dfbe86a8 (diff)
downloadlinux-2.6.34-ux500-0ee719527229fa86ace8e3abccae3c2a8bbfd6db.tar.gz
ahci: redo stopping DMA engines on empty ports
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> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libahci.c21
1 files changed, 3 insertions, 18 deletions
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 1984a6e89e8..261f86d102e 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)