Messages in this thread Patch in this message | | | Date | Wed, 30 Jul 2008 16:27:17 -0700 | From | Greg KH <> | Subject | [patch 16/29] ahci: retry enabling AHCI a few times before spitting out WARN_ON() |
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2.6.25-stable review patch. If anyone has any objections, please let us know.
------------------ From: Tejun Heo <htejun@gmail.com>
commit 15fe982e429e0e6b7466719acb6cfd9dbfe47f0c upstream
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> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/ata/ahci.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
--- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -634,16 +634,27 @@ static inline void __iomem *ahci_port_ba 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); } /** --
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