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sata_highbank: increase retry count but shorten duration for Calxeda controller

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Increase the retry count for the hard reset function to 100 but
shorten the time out period to 500 ms. See the comment for
ahci_highbank_hardreset for the reasons why those vaulues were
chosen.

Signed-off-by: Mark Langsdorf <mark.langsdorf@calxeda.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
This commit is contained in:
Mark Langsdorf 2013-06-03 08:22:54 -05:00 committed by Tejun Heo
parent 52a2a1087b
commit ddfef5de3d
1 changed files with 18 additions and 2 deletions
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20
drivers/ata/sata_highbank.c
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@ -196,10 +196,26 @@ static int highbank_initialize_phys(struct device *dev, void __iomem *addr)
return 0;
}
/*
* The Calxeda SATA phy intermittently fails to bring up a link with Gen3
* Retrying the phy hard reset can work around the issue, but the drive
* may fail again. In less than 150 out of 15000 test runs, it took more
* than 10 tries for the link to be established (but never more than 35).
* Triple the maximum observed retry count to provide plenty of margin for
* rare events and to guarantee that the link is established.
*
* Also, the default 2 second time-out on a failed drive is too long in
* this situation. The uboot implementation of the same driver function
* uses a much shorter time-out period and never experiences a time out
* issue. Reducing the time-out to 500ms improves the responsiveness.
* The other timing constants were kept the same as the stock AHCI driver.
* This change was also tested 15000 times on 24 drives and none of them
* experienced a time out.
*/
static int ahci_highbank_hardreset(struct ata_link *link, unsigned int *class,
unsigned long deadline)
{
const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
static const unsigned long timing[] = { 5, 100, 500};
struct ata_port *ap = link->ap;
struct ahci_port_priv *pp = ap->private_data;
u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
@ -207,7 +223,7 @@ static int ahci_highbank_hardreset(struct ata_link *link, unsigned int *class,
bool online;
u32 sstatus;
int rc;
int retry = 10;
int retry = 100;
ahci_stop_engine(ap);