diff options
| author | Zhang Rui <rui.zhang@intel.com> | 2008-07-04 13:32:17 +0800 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@redhat.com> | 2008-07-14 15:59:33 -0400 |
| commit | 24920c8a6358bf5532f1336b990b1c0fe2b599ee (patch) | |
| tree | 576c2dcbde9c76e13585ed37208640fbd3dba005 /drivers/ata | |
| parent | 1e9dbc9291738149577cc488fd441f061815e02e (diff) | |
| download | lwn-24920c8a6358bf5532f1336b990b1c0fe2b599ee.tar.gz lwn-24920c8a6358bf5532f1336b990b1c0fe2b599ee.zip | |
AHCI: speed up resume
During resume, sleep 1 second to wait for the HBA reset
to finish is a waste of time.
According to the AHCI 1.2 spec,
We should poll the HOST_CTL register,
and return error if the host reset is not
finished within 1 second.
Test results show that the HBA reset can be done quickly(in usecs).
And this patch may save nearly 1 second during resume.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata')
| -rw-r--r-- | drivers/ata/ahci.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 65d4e968feb4..4ff3f03cf97b 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1142,12 +1142,15 @@ static int ahci_reset_controller(struct ata_host *host) readl(mmio + HOST_CTL); /* flush */ } - /* reset must complete within 1 second, or + /* + * to perform host reset, OS should set HOST_RESET + * and poll until this bit is read to be "0". + * reset must complete within 1 second, or * the hardware should be considered fried. */ - ssleep(1); + tmp = ata_wait_register(mmio + HOST_CTL, HOST_RESET, + HOST_RESET, 10, 1000); - tmp = readl(mmio + HOST_CTL); if (tmp & HOST_RESET) { dev_printk(KERN_ERR, host->dev, "controller reset failed (0x%x)\n", tmp); |