From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
usb-storage: Workaround devices with bogus sense size
Some devices, such as Huawei E169, advertise more than the standard
amount of sense data, causing us to set US_FL_SANE_SENSE, assuming
they support it. However, they subsequently fail the request sense
with that size.
This works around it generically. When a sense request fails due to
a device returning an error, US_FL_SANE_SENSE was set, and that sense
request used a larger sense size, we retry with a smaller size before
giving up.
Based on an original patch by Ben Efros <ben@xxxxxxxxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/storage/transport.c | 17 ++++++++++++++++-
1 files changed, 16 insertions(+), 1 deletions(-)
diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index 3a4fb02..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");
--
1.6.4.2
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