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| author | Catalin Marinas <catalin.marinas@arm.com> | 2010-06-10 20:02:12 +0400 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@redhat.com> | 2010-06-11 00:06:48 +0400 |
| commit | 1082345290dbc66c19877662cb24c18ee4ae1296 (patch) | |
| tree | 601a05fd1e26e161c4f60bef35dab7411dac0e5b | |
| parent | 14e45c15e1dcc4d972b41343661683efd60fed72 (diff) | |
| download | linux-1082345290dbc66c19877662cb24c18ee4ae1296.tar.xz | |
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>
| -rw-r--r-- | drivers/ata/sata_sil24.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c index a7f0139c3aae..be7726d7686d 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); |