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usb-storage: Workaround devices with bogus sense size

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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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Benjamin Herrenschmidt 2009-10-13 15:53:47 +11:00 committed by Greg Kroah-Hartman
parent 36f21329d2
commit b8430e1b82
1 changed files with 16 additions and 1 deletions
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17
drivers/usb/storage/transport.c
View file

@ -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");