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authorTejun Heo <htejun@gmail.com>2008-04-23 20:52:58 +0900
committerJeff Garzik <jgarzik@redhat.com>2008-04-25 00:45:13 -0400
commit15fe982e429e0e6b7466719acb6cfd9dbfe47f0c (patch)
treede5ac9b692257050bf8dbdb6ebe02e780fddad46 /drivers/ata/ahci.c
parent411cb3869afd91ed40e8f12df64cd9e315356305 (diff)
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ahci: retry enabling AHCI a few times before spitting out WARN_ON()
Some chips need AHCI_EN set more than once to actually set it. Try a few times before giving up and spitting out WARN_ON(). Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Peer Chen <pchen@nvidia.com> Cc: Volker Armin Hemmann <volker.armin.hemmann@tu-clausthal.de> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/ahci.c')
-rw-r--r--drivers/ata/ahci.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 986e332..7c4f886 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -556,16 +556,27 @@ static inline void __iomem *ahci_port_base(struct ata_port *ap)
static void ahci_enable_ahci(void __iomem *mmio)
{
+ int i;
u32 tmp;
/* turn on AHCI_EN */
tmp = readl(mmio + HOST_CTL);
- if (!(tmp & HOST_AHCI_EN)) {
+ if (tmp & HOST_AHCI_EN)
+ return;
+
+ /* Some controllers need AHCI_EN to be written multiple times.
+ * Try a few times before giving up.
+ */
+ for (i = 0; i < 5; i++) {
tmp |= HOST_AHCI_EN;
writel(tmp, mmio + HOST_CTL);
tmp = readl(mmio + HOST_CTL); /* flush && sanity check */
- WARN_ON(!(tmp & HOST_AHCI_EN));
+ if (tmp & HOST_AHCI_EN)
+ return;
+ msleep(10);
}
+
+ WARN_ON(1);
}
/**