[PATCH] libata-hp-prep: add prereset() method and implement ata_std_prereset()
With hotplug, every reset might be a probing reset and thus something
similar to probe_init() is needed. prereset() method is called before
a series of resets to a port and is the counterpart of postreset().
prereset() can tell EH to use different type of reset or skip reset by
modifying ehc->i.action.
This patch also implements ata_std_prereset(). Most controllers
should be able to use this function directly or with some wrapping.
After hotplug, different controllers need different actions to resume
the PHY and detect the newly attached device. Controllers can be
categorized as follows.
* Controllers which can wait for the first D2H FIS after hotplug.
Note that if the waiting is implemented by polling TF status, there
needs to be a way to set BSY on PHY status change. It can be
implemented by hardware or with the help of the driver.
* Controllers which can wait for the first D2H FIS after sending
COMRESET. These controllers need to issue COMRESET to wait for the
first FIS. Note that the received D2H FIS could be the first D2H
FIS after POR (power-on-reset) or D2H FIS in response to the
COMRESET. Some controllers use COMRESET as TF status
synchronization point and clear TF automatically (sata_sil).
* Controllers which cannot wait for the first D2H FIS reliably.
Blindly issuing SRST to spinning-up device often results in command
issue failure or timeout, causing extended delay. For these
controllers, ata_std_prereset() explicitly waits ATA_SPINUP_WAIT
(currently 8s) to give newly attached device time to spin up, then
issues reset. Note that failing to getting ready in ATA_SPINUP_WAIT
is not critical. libata will retry. So, the timeout needs to be
long enough to spin up most devices.
LLDDs can tell ata_std_prereset() which of above action is needed with
ATA_FLAG_HRST_TO_RESUME and ATA_FLAG_SKIP_D2H_BSY flags. These flags
are PHY-specific property and will be moved to ata_link later.
While at it, this patch unifies function typedef's such that they all
have named arguments.
Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 9173d8f..0e66f14 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -1318,20 +1318,58 @@
}
}
-static int ata_eh_reset(struct ata_port *ap, ata_reset_fn_t softreset,
+static int ata_eh_reset(struct ata_port *ap,
+ 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];
int tries = ATA_EH_RESET_TRIES;
+ unsigned int action;
ata_reset_fn_t reset;
int i, rc;
+ /* Determine which reset to use and record in ehc->i.action.
+ * prereset() may examine and modify it.
+ */
+ action = ehc->i.action;
+ ehc->i.action &= ~ATA_EH_RESET_MASK;
if (softreset && (!hardreset || (!sata_set_spd_needed(ap) &&
- !(ehc->i.action & ATA_EH_HARDRESET))))
- reset = softreset;
+ !(action & ATA_EH_HARDRESET))))
+ ehc->i.action |= ATA_EH_SOFTRESET;
else
+ ehc->i.action |= ATA_EH_HARDRESET;
+
+ if (prereset) {
+ rc = prereset(ap);
+ if (rc) {
+ ata_port_printk(ap, KERN_ERR,
+ "prereset failed (errno=%d)\n", rc);
+ return rc;
+ }
+ }
+
+ /* prereset() might have modified ehc->i.action */
+ if (ehc->i.action & ATA_EH_HARDRESET)
reset = hardreset;
+ else if (ehc->i.action & ATA_EH_SOFTRESET)
+ reset = softreset;
+ else {
+ /* prereset told us not to reset, bang classes and return */
+ for (i = 0; i < ATA_MAX_DEVICES; i++)
+ classes[i] = ATA_DEV_NONE;
+ return 0;
+ }
+
+ /* did prereset() screw up? if so, fix up to avoid oopsing */
+ if (!reset) {
+ ata_port_printk(ap, KERN_ERR, "BUG: prereset() requested "
+ "invalid reset type\n");
+ if (softreset)
+ reset = softreset;
+ else
+ reset = hardreset;
+ }
retry:
ata_port_printk(ap, KERN_INFO, "%s resetting port\n",
@@ -1424,6 +1462,7 @@
/**
* ata_eh_recover - recover host port after error
* @ap: host port to recover
+ * @prereset: prereset method (can be NULL)
* @softreset: softreset method (can be NULL)
* @hardreset: hardreset method (can be NULL)
* @postreset: postreset method (can be NULL)
@@ -1440,8 +1479,8 @@
* RETURNS:
* 0 on success, -errno on failure.
*/
-static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset,
- ata_reset_fn_t hardreset,
+static int ata_eh_recover(struct ata_port *ap, 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;
@@ -1469,7 +1508,8 @@
if (ehc->i.action & ATA_EH_RESET_MASK) {
ata_eh_freeze_port(ap);
- rc = ata_eh_reset(ap, softreset, hardreset, postreset);
+ rc = ata_eh_reset(ap, prereset, softreset, hardreset,
+ postreset);
if (rc) {
ata_port_printk(ap, KERN_ERR,
"reset failed, giving up\n");
@@ -1586,6 +1626,7 @@
/**
* ata_do_eh - do standard error handling
* @ap: host port to handle error for
+ * @prereset: prereset method (can be NULL)
* @softreset: softreset method (can be NULL)
* @hardreset: hardreset method (can be NULL)
* @postreset: postreset method (can be NULL)
@@ -1595,11 +1636,12 @@
* LOCKING:
* Kernel thread context (may sleep).
*/
-void ata_do_eh(struct ata_port *ap, ata_reset_fn_t softreset,
- ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
+void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
+ ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
+ ata_postreset_fn_t postreset)
{
ata_eh_autopsy(ap);
ata_eh_report(ap);
- ata_eh_recover(ap, softreset, hardreset, postreset);
+ ata_eh_recover(ap, prereset, softreset, hardreset, postreset);
ata_eh_finish(ap);
}
