Some links on some PMPs locks up on SRST and/or report incorrect
device signature. Implement ATA_LFLAG_NO_SRST, ASSUME_ATA and
ASSUME_SEMB to handle these quirky links. NO_SRST makes EH avoid
SRST. ASSUME_ATA and SEMB forces class code to ATA and SEMB_UNSUP
respectively. Note that SEMB isn't currently supported yet so the
_UNSUP variant is used.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/ata/libata-eh.c | 42 ++++++++++++++++++++++++++++++++----------
include/linux/libata.h | 4 ++++
2 files changed, 36 insertions(+), 10 deletions(-)
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 3779067..5d06509 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1768,14 +1768,18 @@ static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
return 0;
}
-static int ata_eh_followup_srst_needed(int rc, int classify,
+static int ata_eh_followup_srst_needed(struct ata_link *link,
+ int rc, int classify,
const unsigned int *classes)
{
+ if (link->flags & ATA_LFLAG_NO_SRST)
+ return 0;
if (rc == -EAGAIN)
return 1;
if (rc != 0)
return 0;
- if (classify && classes[0] == ATA_DEV_UNKNOWN)
+ if (classify && !(link->flags & ATA_LFLAG_ASSUME_CLASS) &&
+ classes[0] == ATA_DEV_UNKNOWN)
return 1;
return 0;
}
@@ -1802,7 +1806,8 @@ int ata_eh_reset(struct ata_link *link, int classify,
*/
action = ehc->i.action;
ehc->i.action &= ~ATA_EH_RESET_MASK;
- if (softreset && (!hardreset || (!sata_set_spd_needed(link) &&
+ if (softreset && (!hardreset || (!(link->flags & ATA_LFLAG_NO_SRST) &&
+ !sata_set_spd_needed(link) &&
!(action & ATA_EH_HARDRESET))))
ehc->i.action |= ATA_EH_SOFTRESET;
else
@@ -1865,7 +1870,7 @@ int ata_eh_reset(struct ata_link *link, int classify,
rc = ata_do_reset(link, reset, classes, deadline);
if (reset == hardreset &&
- ata_eh_followup_srst_needed(rc, classify, classes)) {
+ ata_eh_followup_srst_needed(link, rc, classify, classes)) {
/* okay, let's do follow-up softreset */
reset = softreset;
@@ -1880,8 +1885,8 @@ int ata_eh_reset(struct ata_link *link, int classify,
ata_eh_about_to_do(link, NULL, ATA_EH_RESET_MASK);
rc = ata_do_reset(link, reset, classes, deadline);
- if (rc == 0 && classify &&
- classes[0] == ATA_DEV_UNKNOWN) {
+ if (rc == 0 && classify && classes[0] == ATA_DEV_UNKNOWN &&
+ !(link->flags & ATA_LFLAG_ASSUME_CLASS)) {
ata_link_printk(link, KERN_ERR,
"classification failed\n");
rc = -EINVAL;
@@ -1889,6 +1894,10 @@ int ata_eh_reset(struct ata_link *link, int classify,
}
}
+ /* if we skipped follow-up srst, clear rc */
+ if (rc == -EAGAIN)
+ rc = 0;
+
if (rc && try < ARRAY_SIZE(ata_eh_reset_timeouts)) {
unsigned long now = jiffies;
@@ -1913,12 +1922,25 @@ int ata_eh_reset(struct ata_link *link, int classify,
if (rc == 0) {
u32 sstatus;
- /* After the reset, the device state is PIO 0 and the
- * controller state is undefined. Record the mode.
- */
- ata_link_for_each_dev(dev, link)
+ ata_link_for_each_dev(dev, link) {
+ /* After the reset, the device state is PIO 0
+ * and the controller state is undefined.
+ * Record the mode.
+ */
dev->pio_mode = XFER_PIO_0;
+ if (ata_link_offline(link))
+ continue;
+
+ /* apply class override and convert UNKNOWN to NONE */
+ if (link->flags & ATA_LFLAG_ASSUME_ATA)
+ classes[dev->devno] = ATA_DEV_ATA;
+ else if (link->flags & ATA_LFLAG_ASSUME_SEMB)
+ classes[dev->devno] = ATA_DEV_SEMB_UNSUP; /* not yet */
+ else if (classes[dev->devno] == ATA_DEV_UNKNOWN)
+ classes[dev->devno] = ATA_DEV_NONE;
+ }
+
/* record current link speed */
if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
link->sata_spd = (sstatus >> 4) & 0xf;
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 349180a..57da3ba 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -163,6 +163,10 @@ enum {
ATA_LFLAG_HRST_TO_RESUME = (1 << 0), /* hardreset to resume link */
ATA_LFLAG_SKIP_D2H_BSY = (1 << 1), /* can't wait for the first D2H
* Register FIS clearing BSY */
+ ATA_LFLAG_NO_SRST = (1 << 2), /* avoid softreset */
+ ATA_LFLAG_ASSUME_ATA = (1 << 3), /* assume ATA class */
+ ATA_LFLAG_ASSUME_SEMB = (1 << 4), /* assume SEMB class */
+ ATA_LFLAG_ASSUME_CLASS = ATA_LFLAG_ASSUME_ATA | ATA_LFLAG_ASSUME_SEMB,
/* struct ata_port flags */
ATA_FLAG_SLAVE_POSS = (1 << 0), /* host supports slave dev */
--
1.5.0.3
-
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