[PATCH AUTOSEL for 4.4 045/167] USB: ene_usb6250: fix first command execution

[Sasha Levin]

From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit 4b309f1c4972c8f09e03ac64fc63510dbf5591a4 ]

In the ene_usb6250 sub-driver for usb-storage, the ene_transport()
routine is supposed to initialize the driver before executing the
current command, if the initialization has not already been performed.
However, a bug in the routine causes it to skip the command after
doing the initialization.  Also, the routine does not return an
appropriate error code if either the initialization or the command
fails.

As a result of the first bug, the first command (a SCSI INQUIRY) is
not carried out.  The results can be seen in the system log, in the
form of a warning message and empty or garbage INQUIRY data:

Apr 18 22:40:08 notebook2 kernel: scsi host6: scsi scan: INQUIRY result too short (5), using 36
Apr 18 22:40:08 notebook2 kernel: scsi 6:0:0:0: Direct-Access                                    PQ: 0 ANSI: 0

This patch fixes both errors.

Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-and-tested-by: Andreas Hartmann <andihartmann@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 drivers/usb/storage/ene_ub6250.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/storage/ene_ub6250.c b/drivers/usb/storage/ene_ub6250.c
index 091e8ec7a6c0..eebfa09bccc1 100644
--- a/drivers/usb/storage/ene_ub6250.c
+++ b/drivers/usb/storage/ene_ub6250.c
@@ -2306,21 +2306,22 @@ static int ms_scsi_irp(struct us_data *us, struct scsi_cmnd *srb)
 
 static int ene_transport(struct scsi_cmnd *srb, struct us_data *us)
 {
-	int result = 0;
+	int result = USB_STOR_XFER_GOOD;
 	struct ene_ub6250_info *info = (struct ene_ub6250_info *)(us->extra);
 
 	/*US_DEBUG(usb_stor_show_command(us, srb)); */
 	scsi_set_resid(srb, 0);
-	if (unlikely(!(info->SD_Status.Ready || info->MS_Status.Ready))) {
+	if (unlikely(!(info->SD_Status.Ready || info->MS_Status.Ready)))
 		result = ene_init(us);
-	} else {
+	if (result == USB_STOR_XFER_GOOD) {
+		result = USB_STOR_TRANSPORT_ERROR;
 		if (info->SD_Status.Ready)
 			result = sd_scsi_irp(us, srb);
 
 		if (info->MS_Status.Ready)
 			result = ms_scsi_irp(us, srb);
 	}
-	return 0;
+	return result;
 }
 
 static struct scsi_host_template ene_ub6250_host_template;
-- 
2.14.1