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path: root/drivers/usb/storage/transport.c
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-rw-r--r--drivers/usb/storage/transport.c46
1 files changed, 38 insertions, 8 deletions
diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index e20dc52..589f6b4 100644
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -696,7 +696,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
/* device supports and needs bigger sense buffer */
if (us->fflags & US_FL_SANE_SENSE)
sense_size = ~0;
-
+Retry_Sense:
US_DEBUGP("Issuing auto-REQUEST_SENSE\n");
scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sense_size);
@@ -720,6 +720,21 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
srb->result = DID_ABORT << 16;
goto Handle_Errors;
}
+
+ /* Some devices claim to support larger sense but fail when
+ * trying to request it. When a transport failure happens
+ * using US_FS_SANE_SENSE, we always retry with a standard
+ * (small) sense request. This fixes some USB GSM modems
+ */
+ if (temp_result == USB_STOR_TRANSPORT_FAILED &&
+ (us->fflags & US_FL_SANE_SENSE) &&
+ sense_size != US_SENSE_SIZE) {
+ US_DEBUGP("-- auto-sense failure, retry small sense\n");
+ sense_size = US_SENSE_SIZE;
+ goto Retry_Sense;
+ }
+
+ /* Other failures */
if (temp_result != USB_STOR_TRANSPORT_GOOD) {
US_DEBUGP("-- auto-sense failure\n");
@@ -768,17 +783,32 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
/* set the result so the higher layers expect this data */
srb->result = SAM_STAT_CHECK_CONDITION;
- /* If things are really okay, then let's show that. Zero
- * out the sense buffer so the higher layers won't realize
- * we did an unsolicited auto-sense. */
- if (result == USB_STOR_TRANSPORT_GOOD &&
- /* Filemark 0, ignore EOM, ILI 0, no sense */
+ /* We often get empty sense data. This could indicate that
+ * everything worked or that there was an unspecified
+ * problem. We have to decide which.
+ */
+ if ( /* Filemark 0, ignore EOM, ILI 0, no sense */
(srb->sense_buffer[2] & 0xaf) == 0 &&
/* No ASC or ASCQ */
srb->sense_buffer[12] == 0 &&
srb->sense_buffer[13] == 0) {
- srb->result = SAM_STAT_GOOD;
- srb->sense_buffer[0] = 0x0;
+
+ /* If things are really okay, then let's show that.
+ * Zero out the sense buffer so the higher layers
+ * won't realize we did an unsolicited auto-sense.
+ */
+ if (result == USB_STOR_TRANSPORT_GOOD) {
+ srb->result = SAM_STAT_GOOD;
+ srb->sense_buffer[0] = 0x0;
+
+ /* If there was a problem, report an unspecified
+ * hardware error to prevent the higher layers from
+ * entering an infinite retry loop.
+ */
+ } else {
+ srb->result = DID_ERROR << 16;
+ srb->sense_buffer[2] = HARDWARE_ERROR;
+ }
}
}
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