This is a note to let you know that I've just added the patch titled
sata_highbank: increase retry count but shorten duration for
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sata_highbank-increase-retry-count-but-shorten-duration-for.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ddfef5de3d716f77bad32dbbba6b280158dfd721 Mon Sep 17 00:00:00 2001
From: Mark Langsdorf <mark.langsdorf@xxxxxxxxxxx>
Date: Mon, 3 Jun 2013 08:22:54 -0500
Subject: sata_highbank: increase retry count but shorten duration for
Calxeda controller
From: Mark Langsdorf <mark.langsdorf@xxxxxxxxxxx>
commit ddfef5de3d716f77bad32dbbba6b280158dfd721 upstream.
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@xxxxxxxxxxx>
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/ata/sata_highbank.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
--- a/drivers/ata/sata_highbank.c
+++ b/drivers/ata/sata_highbank.c
@@ -196,10 +196,26 @@ static int highbank_initialize_phys(stru
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(struc
bool online;
u32 sstatus;
int rc;
- int retry = 10;
+ int retry = 100;
ahci_stop_engine(ap);
Patches currently in stable-queue which might be from mark.langsdorf@xxxxxxxxxxx are
queue-3.10/sata_highbank-increase-retry-count-but-shorten-duration-for.patch
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