cdc-acm: Add support of ATOL FPrint fiscal printers

commit 15bf722e upstream.

ATOL FPrint fiscal printers require usb_clear_halt to be executed
to work properly. Add quirk to fix the issue.
Signed-off-by: Alexey Sokolov <sokolov@7pikes.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/usb/class/cdc-acm.c

@@ -1295,6 +1295,11 @@ static int acm_probe(struct usb_interface *intf,
 
 	acm_table[minor] = acm;
 
+	if (quirks & CLEAR_HALT_CONDITIONS) {
+		usb_clear_halt(usb_dev, usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress));
+		usb_clear_halt(usb_dev, usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress));
+	}
+
 	return 0;
 alloc_fail7:
 	for (i = 0; i < ACM_NW; i++)
@@ -1574,6 +1579,10 @@ static const struct usb_device_id acm_ids[] = {
 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
 	},
 
+	{ USB_DEVICE(0x2912, 0x0001), /* ATOL FPrint */
+	.driver_info = CLEAR_HALT_CONDITIONS,
+	},
+
 	/* Nokia S60 phones expose two ACM channels. The first is
 	 * a modem and is picked up by the standard AT-command
 	 * information below. The second is 'vendor-specific' but

drivers/usb/class/cdc-acm.h

@@ -127,3 +127,4 @@ struct acm {
 #define NO_CAP_LINE			4
 #define NOT_A_MODEM			8
 #define NO_DATA_INTERFACE		16
+#define CLEAR_HALT_CONDITIONS		BIT(7)