libata-acpi: improve _GTF execution error handling and reporting

As _GTF commands can't transfer data, device error never signals
transfer error.  It indicates that the device vetoed the operation, so
it's meaningless to retry.

This patch makes libata-acpi to report and continue on device errors
when executing _GTF commands.  Also commands rejected by device don't
contribute to the number of _GTF commands executed.

While at it, update _GTF execution reporting such that all successful
commands are logged at KERN_DEBUG and rename taskfile_load_raw() to
ata_acpi_run_tf() for consistency.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 5932ae2..d4cb557 100644 (file)
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -466,7 +466,7 @@ int ata_acpi_cbl_80wire(struct ata_port *ap)
 EXPORT_SYMBOL_GPL(ata_acpi_cbl_80wire);
 
 /**
- * taskfile_load_raw - send taskfile registers to host controller
+ * ata_acpi_run_tf - send taskfile registers to host controller
  * @dev: target ATA device
  * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
  *
@@ -485,14 +485,17 @@ EXPORT_SYMBOL_GPL(ata_acpi_cbl_80wire);
  * EH context.
  *
  * RETURNS:
- * 0 on success, -errno on failure.
+ * 1 if command is executed successfully.  0 if ignored or rejected,
+ * -errno on other errors.
  */
-static int taskfile_load_raw(struct ata_device *dev,
-                             const struct ata_acpi_gtf *gtf)
+static int ata_acpi_run_tf(struct ata_device *dev,
+                          const struct ata_acpi_gtf *gtf)
 {
-       struct ata_port *ap = dev->link->ap;
        struct ata_taskfile tf, rtf;
        unsigned int err_mask;
+       const char *level;
+       char msg[60];
+       int rc;
 
        if ((gtf->tf[0] == 0) && (gtf->tf[1] == 0) && (gtf->tf[2] == 0)
            && (gtf->tf[3] == 0) && (gtf->tf[4] == 0) && (gtf->tf[5] == 0)
@@ -512,24 +515,39 @@ static int taskfile_load_raw(struct ata_device *dev,
        tf.device  = gtf->tf[5];        /* 0x1f6 */
        tf.command = gtf->tf[6];        /* 0x1f7 */
 
-       if (ata_msg_probe(ap))
-               ata_dev_printk(dev, KERN_DEBUG, "executing ACPI cmd "
-                              "%02x/%02x:%02x:%02x:%02x:%02x:%02x\n",
-                              tf.command, tf.feature, tf.nsect,
-                              tf.lbal, tf.lbam, tf.lbah, tf.device);
-
        rtf = tf;
        err_mask = ata_exec_internal(dev, &rtf, NULL, DMA_NONE, NULL, 0, 0);
-       if (err_mask) {
-               ata_dev_printk(dev, KERN_ERR,
-                       "ACPI cmd %02x/%02x:%02x:%02x:%02x:%02x:%02x failed "
-                       "(Emask=0x%x Stat=0x%02x Err=0x%02x)\n",
-                       tf.command, tf.feature, tf.nsect, tf.lbal, tf.lbam,
-                       tf.lbah, tf.device, err_mask, rtf.command, rtf.feature);
-               return -EIO;
+
+       switch (err_mask) {
+       case 0:
+               level = KERN_DEBUG;
+               snprintf(msg, sizeof(msg), "succeeded");
+               rc = 1;
+               break;
+
+       case AC_ERR_DEV:
+               level = KERN_INFO;
+               snprintf(msg, sizeof(msg),
+                        "rejected by device (Stat=0x%02x Err=0x%02x)",
+                        rtf.command, rtf.feature);
+               rc = 0;
+               break;
+
+       default:
+               level = KERN_ERR;
+               snprintf(msg, sizeof(msg),
+                        "failed (Emask=0x%x Stat=0x%02x Err=0x%02x)",
+                        err_mask, rtf.command, rtf.feature);
+               rc = -EIO;
+               break;
        }
 
-       return 0;
+       ata_dev_printk(dev, level,
+                      "ACPI cmd %02x/%02x:%02x:%02x:%02x:%02x:%02x %s\n",
+                      tf.command, tf.feature, tf.nsect, tf.lbal,
+                      tf.lbam, tf.lbah, tf.device, msg);
+
+       return rc;
 }
 
 /**
@@ -558,22 +576,19 @@ static int ata_acpi_exec_tfs(struct ata_device *dev, int *nr_executed)
        gtf_count = rc;
 
        /* execute them */
-       for (i = 0, rc = 0; i < gtf_count; i++) {
-               int tmp;
-
-               /* ACPI errors are eventually ignored.  Run till the
-                * end even after errors.
-                */
-               tmp = taskfile_load_raw(dev, gtf++);
-               if (!rc)
-                       rc = tmp;
-
-               (*nr_executed)++;
+       for (i = 0; i < gtf_count; i++) {
+               rc = ata_acpi_run_tf(dev, gtf++);
+               if (rc < 0)
+                       break;
+               if (rc)
+                       (*nr_executed)++;
        }
 
        ata_acpi_clear_gtf(dev);
 
-       return rc;
+       if (rc < 0)
+               return rc;
+       return 0;
 }
 
 /**