Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b8430e1b authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Greg Kroah-Hartman
Browse files

usb-storage: Workaround devices with bogus sense size 



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@pc-doctor.com>

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 36f21329

drivers/usb/storage/transport.c

+16 −1
Original line number Diff line number Diff line
@@ -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");