[PATCH] USB Storage: ignore bogus residue values

This patch allows usb-storage to ignore the reported residue values when
required by some devices.  A few devices are included... I know more are
waiting to be merged into unusual_devs.h

In case anyone is curious... yes, these are broken devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/storage/transport.c

@@ -1055,8 +1055,13 @@ int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
 
 	/* try to compute the actual residue, based on how much data
 	 * was really transferred and what the device tells us */
-	residue = min(residue, transfer_length);
-	srb->resid = max(srb->resid, (int) residue);
+	if (residue) {
+		if (!(us->flags & US_FL_IGNORE_RESIDUE) ||
+				srb->sc_data_direction == DMA_TO_DEVICE) {
+			residue = min(residue, transfer_length);
+			srb->resid = max(srb->resid, (int) residue);
+		}
+	}
 
 	/* based on the status code, we report good or bad */
 	switch (bcs->Status) {

drivers/usb/storage/unusual_devs.h

@@ -268,6 +268,13 @@ UNUSUAL_DEV(  0x0525, 0xa140, 0x0100, 0x0100,
 		US_SC_8070, US_PR_BULK, NULL,
 		US_FL_FIX_INQUIRY ),
 
+/* Reported by Iacopo Spalletti <avvisi@spalletti.it> */
+UNUSUAL_DEV(  0x052b, 0x1807, 0x0100, 0x0100,
+		"Tekom Technologies, Inc",
+		"300_CAMERA",
+		US_SC_DEVICE, US_PR_DEVICE, NULL,
+		US_FL_IGNORE_RESIDUE ),
+
 /* This entry is needed because the device reports Sub=ff */
 UNUSUAL_DEV(  0x054c, 0x0010, 0x0106, 0x0450, 
 		"Sony",
@@ -811,7 +818,14 @@ UNUSUAL_DEV( 0x0ed1, 0x6660, 0x0100, 0x0300,
 		"Solid state disk",
 		US_SC_DEVICE, US_PR_DEVICE, NULL,
 		US_FL_FIX_INQUIRY ),
-		
+
+/* Reported by Rastislav Stanik <rs_kernel@yahoo.com> */
+UNUSUAL_DEV(  0x0ea0, 0x6828, 0x0110, 0x0110,
+		"USB",
+		"Flash Disk",
+		US_SC_DEVICE, US_PR_DEVICE, NULL,
+		US_FL_IGNORE_RESIDUE ),
+
 /* Reported by Kevin Cernekee <kpc-usbdev@gelato.uiuc.edu>
  * Tested on hardware version 1.10.
  * Entry is needed only for the initializer function override.
@@ -833,6 +847,13 @@ UNUSUAL_DEV(  0x1065, 0x2136, 0x0000, 0x9999,
 		US_SC_DEVICE, US_PR_DEVICE, NULL,
 		US_FL_MODE_XLATE ),
 
+/* Reported by Kotrla Vitezslav <kotrla@ceb.cz> */
+UNUSUAL_DEV(  0x1370, 0x6828, 0x0110, 0x0110,
+		"SWISSBIT",
+		"Black Silver",
+		US_SC_DEVICE, US_PR_DEVICE, NULL,
+		US_FL_IGNORE_RESIDUE ),
+
 #ifdef CONFIG_USB_STORAGE_SDDR55
 UNUSUAL_DEV(  0x55aa, 0xa103, 0x0000, 0x9999, 
 		"Sandisk",

drivers/usb/storage/usb.h

@@ -73,6 +73,7 @@ struct us_unusual_dev {
 #define US_FL_SCM_MULT_TARG   0x00000020 /* supports multiple targets	    */
 #define US_FL_FIX_INQUIRY     0x00000040 /* INQUIRY response needs faking   */
 #define US_FL_FIX_CAPACITY    0x00000080 /* READ CAPACITY response too big  */
+#define US_FL_IGNORE_RESIDUE  0x00000100 /* reported residue is wrong	    */
 
 /* Dynamic flag definitions: used in set_bit() etc. */
 #define US_FLIDX_URB_ACTIVE	18  /* 0x00040000  current_urb is in use  */