USB: g_file_storage: Set sense info Valid bit only when needed

Strictly speaking, the Valid bit in SCSI sense data is supposed to
be set only when the Information field contains a valid number.  This
patch (as793) turns off the Valid bit when the Information field
hasn't been set.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index d472c9c..c83d3b6 100644 (file)
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -567,6 +567,7 @@ struct lun {
        unsigned int    ro : 1;
        unsigned int    prevent_medium_removal : 1;
        unsigned int    registered : 1;
+       unsigned int    info_valid : 1;
 
        u32             sense_data;
        u32             sense_data_info;
@@ -1656,6 +1657,7 @@ static int do_read(struct fsg_dev *fsg)
                        curlun->sense_data =
                                        SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
                        curlun->sense_data_info = file_offset >> 9;
+                       curlun->info_valid = 1;
                        bh->inreq->length = 0;
                        bh->state = BUF_STATE_FULL;
                        break;
@@ -1691,6 +1693,7 @@ static int do_read(struct fsg_dev *fsg)
                if (nread < amount) {
                        curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
                        curlun->sense_data_info = file_offset >> 9;
+                       curlun->info_valid = 1;
                        break;
                }
 
@@ -1785,6 +1788,7 @@ static int do_write(struct fsg_dev *fsg)
                                curlun->sense_data =
                                        SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
                                curlun->sense_data_info = usb_offset >> 9;
+                               curlun->info_valid = 1;
                                continue;
                        }
                        amount -= (amount & 511);
@@ -1827,6 +1831,7 @@ static int do_write(struct fsg_dev *fsg)
                        if (bh->outreq->status != 0) {
                                curlun->sense_data = SS_COMMUNICATION_FAILURE;
                                curlun->sense_data_info = file_offset >> 9;
+                               curlun->info_valid = 1;
                                break;
                        }
 
@@ -1868,6 +1873,7 @@ static int do_write(struct fsg_dev *fsg)
                        if (nwritten < amount) {
                                curlun->sense_data = SS_WRITE_ERROR;
                                curlun->sense_data_info = file_offset >> 9;
+                               curlun->info_valid = 1;
                                break;
                        }
 
@@ -2010,6 +2016,7 @@ static int do_verify(struct fsg_dev *fsg)
                        curlun->sense_data =
                                        SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
                        curlun->sense_data_info = file_offset >> 9;
+                       curlun->info_valid = 1;
                        break;
                }
 
@@ -2036,6 +2043,7 @@ static int do_verify(struct fsg_dev *fsg)
                if (nread == 0) {
                        curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
                        curlun->sense_data_info = file_offset >> 9;
+                       curlun->info_valid = 1;
                        break;
                }
                file_offset += nread;
@@ -2079,6 +2087,7 @@ static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
        struct lun      *curlun = fsg->curlun;
        u8              *buf = (u8 *) bh->buf;
        u32             sd, sdinfo;
+       int             valid;
 
        /*
         * From the SCSI-2 spec., section 7.9 (Unit attention condition):
@@ -2106,15 +2115,18 @@ static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
                fsg->bad_lun_okay = 1;
                sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
                sdinfo = 0;
+               valid = 0;
        } else {
                sd = curlun->sense_data;
                sdinfo = curlun->sense_data_info;
+               valid = curlun->info_valid << 7;
                curlun->sense_data = SS_NO_SENSE;
                curlun->sense_data_info = 0;
+               curlun->info_valid = 0;
        }
 
        memset(buf, 0, 18);
-       buf[0] = 0x80 | 0x70;                   // Valid, current error
+       buf[0] = valid | 0x70;                  // Valid, current error
        buf[2] = SK(sd);
        put_be32(&buf[3], sdinfo);              // Sense information
        buf[7] = 18 - 8;                        // Additional sense length
@@ -2703,6 +2715,7 @@ static int check_command(struct fsg_dev *fsg, int cmnd_size,
                if (fsg->cmnd[0] != SC_REQUEST_SENSE) {
                        curlun->sense_data = SS_NO_SENSE;
                        curlun->sense_data_info = 0;
+                       curlun->info_valid = 0;
                }
        } else {
                fsg->curlun = curlun = NULL;
@@ -3332,6 +3345,7 @@ static void handle_exception(struct fsg_dev *fsg)
                        curlun->sense_data = curlun->unit_attention_data =
                                        SS_NO_SENSE;
                        curlun->sense_data_info = 0;
+                       curlun->info_valid = 0;
                }
                fsg->state = FSG_STATE_IDLE;
        }