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authorCatalin Marinas <catalin.marinas@arm.com>2010-06-10 17:02:12 +0100
committerJeff Garzik <jgarzik@redhat.com>2010-06-10 16:06:48 -0400
commit1082345290dbc66c19877662cb24c18ee4ae1296 (patch)
tree601a05fd1e26e161c4f60bef35dab7411dac0e5b /drivers/ata
parent14e45c15e1dcc4d972b41343661683efd60fed72 (diff)
downloadlinux-2.6.34-ux500-1082345290dbc66c19877662cb24c18ee4ae1296.tar.gz
sata_sil24: Use memory barriers before issuing commands
The data in the cmd_block buffers may reach the main memory after the writel() to the device ports. This patch introduces two calls to wmb() to ensure the relative ordering. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Colin Tuckley <colin.tuckley@arm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/sata_sil24.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index a7f0139c3aa..be7726d7686 100644
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -622,6 +622,11 @@ static int sil24_exec_polled_cmd(struct ata_port *ap, int pmp,
irq_enabled = readl(port + PORT_IRQ_ENABLE_SET);
writel(PORT_IRQ_COMPLETE | PORT_IRQ_ERROR, port + PORT_IRQ_ENABLE_CLR);
+ /*
+ * The barrier is required to ensure that writes to cmd_block reach
+ * the memory before the write to PORT_CMD_ACTIVATE.
+ */
+ wmb();
writel((u32)paddr, port + PORT_CMD_ACTIVATE);
writel((u64)paddr >> 32, port + PORT_CMD_ACTIVATE + 4);
@@ -895,6 +900,11 @@ static unsigned int sil24_qc_issue(struct ata_queued_cmd *qc)
paddr = pp->cmd_block_dma + tag * sizeof(*pp->cmd_block);
activate = port + PORT_CMD_ACTIVATE + tag * 8;
+ /*
+ * The barrier is required to ensure that writes to cmd_block reach
+ * the memory before the write to PORT_CMD_ACTIVATE.
+ */
+ wmb();
writel((u32)paddr, activate);
writel((u64)paddr >> 32, activate + 4);