[PATCH] libata-hp-prep: implement followup softreset handling
In some cases, hardreset must be followed by SRST.
* some controllers can't classify with hardreset
* some controllers can't wait for !BSY after hardreset (LLDD should
explicitly request followup softreset by returning -EAGAIN)
* (later) PM needs SRST w/ PMP==15 to operate after hardreset
To handle above cases, this patch implements follow-up softreset.
After a hardreset, ata_eh_reset() checks whether any of above
conditions are met and do a follow-up softreset if necessary.
Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 0e66f14..8ecb842 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -1318,16 +1318,28 @@
}
}
-static int ata_eh_reset(struct ata_port *ap,
+static int ata_eh_followup_srst_needed(int rc, int classify,
+ const unsigned int *classes)
+{
+ if (rc == -EAGAIN)
+ return 1;
+ if (rc != 0)
+ return 0;
+ if (classify && classes[0] == ATA_DEV_UNKNOWN)
+ return 1;
+ return 0;
+}
+
+static int ata_eh_reset(struct ata_port *ap, int classify,
ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
{
struct ata_eh_context *ehc = &ap->eh_context;
- unsigned int classes[ATA_MAX_DEVICES];
+ unsigned int *classes = ehc->classes;
int tries = ATA_EH_RESET_TRIES;
unsigned int action;
ata_reset_fn_t reset;
- int i, rc;
+ int i, did_followup_srst, rc;
/* Determine which reset to use and record in ehc->i.action.
* prereset() may examine and modify it.
@@ -1381,10 +1393,44 @@
rc = ata_do_reset(ap, reset, classes);
+ did_followup_srst = 0;
+ if (reset == hardreset &&
+ ata_eh_followup_srst_needed(rc, classify, classes)) {
+ /* okay, let's do follow-up softreset */
+ did_followup_srst = 1;
+ reset = softreset;
+
+ if (!reset) {
+ ata_port_printk(ap, KERN_ERR,
+ "follow-up softreset required "
+ "but no softreset avaliable\n");
+ return -EINVAL;
+ }
+
+ ata_eh_about_to_do(ap, ATA_EH_RESET_MASK);
+ rc = ata_do_reset(ap, reset, classes);
+
+ if (rc == 0 && classify &&
+ classes[0] == ATA_DEV_UNKNOWN) {
+ ata_port_printk(ap, KERN_ERR,
+ "classification failed\n");
+ return -EINVAL;
+ }
+ }
+
if (rc && --tries) {
+ const char *type;
+
+ if (reset == softreset) {
+ if (did_followup_srst)
+ type = "follow-up soft";
+ else
+ type = "soft";
+ } else
+ type = "hard";
+
ata_port_printk(ap, KERN_WARNING,
- "%sreset failed, retrying in 5 secs\n",
- reset == softreset ? "soft" : "hard");
+ "%sreset failed, retrying in 5 secs\n", type);
ssleep(5);
if (reset == hardreset)
@@ -1508,7 +1554,7 @@
if (ehc->i.action & ATA_EH_RESET_MASK) {
ata_eh_freeze_port(ap);
- rc = ata_eh_reset(ap, prereset, softreset, hardreset,
+ rc = ata_eh_reset(ap, 0, prereset, softreset, hardreset,
postreset);
if (rc) {
ata_port_printk(ap, KERN_ERR,