[PATCH] libata: implement ata_drive_probe_reset()
Most low level drivers share supported reset/classify actions and
sequence. This patch implements ata_drive_probe_reset() which helps
constructing ->probe_reset from three component operations -
softreset, hardreset and postreset. This minimizes duplicate code and
yet allows flexibility if needed. The three component operations can
also be shared by EH later.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 147e146..cf91fdc 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2233,6 +2233,94 @@
DPRINTK("EXIT\n");
}
+static int do_probe_reset(struct ata_port *ap, ata_reset_fn_t reset,
+ ata_postreset_fn_t postreset,
+ unsigned int *classes)
+{
+ int i, rc;
+
+ for (i = 0; i < ATA_MAX_DEVICES; i++)
+ classes[i] = ATA_DEV_UNKNOWN;
+
+ rc = reset(ap, 0, classes);
+ if (rc)
+ return rc;
+
+ /* If any class isn't ATA_DEV_UNKNOWN, consider classification
+ * is complete and convert all ATA_DEV_UNKNOWN to
+ * ATA_DEV_NONE.
+ */
+ for (i = 0; i < ATA_MAX_DEVICES; i++)
+ if (classes[i] != ATA_DEV_UNKNOWN)
+ break;
+
+ if (i < ATA_MAX_DEVICES)
+ for (i = 0; i < ATA_MAX_DEVICES; i++)
+ if (classes[i] == ATA_DEV_UNKNOWN)
+ classes[i] = ATA_DEV_NONE;
+
+ if (postreset)
+ postreset(ap, classes);
+
+ return classes[0] != ATA_DEV_UNKNOWN ? 0 : -ENODEV;
+}
+
+/**
+ * ata_drive_probe_reset - Perform probe reset with given methods
+ * @ap: port to reset
+ * @softreset: softreset method (can be NULL)
+ * @hardreset: hardreset method (can be NULL)
+ * @postreset: postreset method (can be NULL)
+ * @classes: resulting classes of attached devices
+ *
+ * Reset the specified port and classify attached devices using
+ * given methods. This function prefers softreset but tries all
+ * possible reset sequences to reset and classify devices. This
+ * function is intended to be used for constructing ->probe_reset
+ * callback by low level drivers.
+ *
+ * Reset methods should follow the following rules.
+ *
+ * - Return 0 on sucess, -errno on failure.
+ * - If classification is supported, fill classes[] with
+ * recognized class codes.
+ * - If classification is not supported, leave classes[] alone.
+ * - If verbose is non-zero, print error message on failure;
+ * otherwise, shut up.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep)
+ *
+ * RETURNS:
+ * 0 on success, -EINVAL if no reset method is avaliable, -ENODEV
+ * if classification fails, and any error code from reset
+ * methods.
+ */
+int ata_drive_probe_reset(struct ata_port *ap,
+ ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
+ ata_postreset_fn_t postreset, unsigned int *classes)
+{
+ int rc = -EINVAL;
+
+ if (softreset) {
+ rc = do_probe_reset(ap, softreset, postreset, classes);
+ if (rc == 0)
+ return 0;
+ }
+
+ if (!hardreset)
+ return rc;
+
+ rc = do_probe_reset(ap, hardreset, postreset, classes);
+ if (rc == 0 || rc != -ENODEV)
+ return rc;
+
+ if (softreset)
+ rc = do_probe_reset(ap, softreset, postreset, classes);
+
+ return rc;
+}
+
static void ata_pr_blacklisted(const struct ata_port *ap,
const struct ata_device *dev)
{
@@ -5180,6 +5268,7 @@
EXPORT_SYMBOL_GPL(sata_phy_reset);
EXPORT_SYMBOL_GPL(__sata_phy_reset);
EXPORT_SYMBOL_GPL(ata_bus_reset);
+EXPORT_SYMBOL_GPL(ata_drive_probe_reset);
EXPORT_SYMBOL_GPL(ata_port_disable);
EXPORT_SYMBOL_GPL(ata_ratelimit);
EXPORT_SYMBOL_GPL(ata_busy_sleep);