| Message ID | 1370014046-5202-1-git-send-email-mark.langsdorf@calxeda.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
On Fri, May 31, 2013 at 10:27:26AM -0500, Mark Langsdorf wrote: > 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. Shorten the Linux time-out value for this driver to 500 ms and > keep the other timing constants 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. For the third time, explain the above in the comment; otherwise, it's not going in.
On 06/02/2013 03:00 AM, Tejun Heo wrote: > On Fri, May 31, 2013 at 10:27:26AM -0500, Mark Langsdorf wrote: > > For the third time, explain the above in the comment; otherwise, it's > not going in. Sorry, I completely misread your requirement. I'll move it to the comment as requested. --Mark Langsdorf Calxeda, Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/ata/sata_highbank.c b/drivers/ata/sata_highbank.c index b20aa96..46ccc1c 100644 --- a/drivers/ata/sata_highbank.c +++ b/drivers/ata/sata_highbank.c @@ -199,7 +199,7 @@ static int highbank_initialize_phys(struct device *dev, void __iomem *addr) 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 +207,7 @@ 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);
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. Shorten the Linux time-out value for this driver to 500 ms and keep the other timing constants 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. Signed-off-by: Mark Langsdorf <mark.langsdorf@calxeda.com> --- Changes from v2 Add static to the timing variable definition Changes from v1 Add const to the timing variable definition Added more detail in why the various numbers were chosen drivers/ata/sata_highbank.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)