UEAGLE: Avoid keyboard driver blocking

Ueagle-atm driver load DSP firmware in function, which is running from
common workqueue. In some (error) circumstances loading firmware may
sleep for long periods (even 60 seconds, depending on timeout). This
block keyboard driver, which also use common workqueue. To fix problem
use custom workqueue in ueagle-atm.
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/atm/ueagle-atm.c

@@ -167,6 +167,7 @@ struct uea_softc {
 	union cmv_dsc cmv_dsc;
 
 	struct work_struct task;
+	struct workqueue_struct *work_q;
 	u16 pageno;
 	u16 ovl;
 
@@ -1830,7 +1831,7 @@ static int uea_start_reset(struct uea_softc *sc)
 	/* start loading DSP */
 	sc->pageno = 0;
 	sc->ovl = 0;
-	schedule_work(&sc->task);
+	queue_work(sc->work_q, &sc->task);
 
 	/* wait for modem ready CMV */
 	ret = wait_cmv_ack(sc);
@@ -2038,13 +2039,13 @@ static void uea_schedule_load_page_e1(struct uea_softc *sc, struct intr_pkt *int
 {
 	sc->pageno = intr->e1_bSwapPageNo;
 	sc->ovl = intr->e1_bOvl >> 4 | intr->e1_bOvl << 4;
-	schedule_work(&sc->task);
+	queue_work(sc->work_q, &sc->task);
 }
 
 static void uea_schedule_load_page_e4(struct uea_softc *sc, struct intr_pkt *intr)
 {
 	sc->pageno = intr->e4_bSwapPageNo;
-	schedule_work(&sc->task);
+	queue_work(sc->work_q, &sc->task);
 }
 
 /*
@@ -2117,6 +2118,13 @@ static int uea_boot(struct uea_softc *sc)
 	init_waitqueue_head(&sc->sync_q);
 	init_waitqueue_head(&sc->cmv_ack_wait);
 
+	sc->work_q = create_workqueue("ueagle-dsp");
+	if (!sc->work_q) {
+		uea_err(INS_TO_USBDEV(sc), "cannot allocate workqueue\n");
+		uea_leaves(INS_TO_USBDEV(sc));
+		return -ENOMEM;
+	}
+
 	if (UEA_CHIP_VERSION(sc) == ADI930)
 		load_XILINX_firmware(sc);
 
@@ -2124,14 +2132,13 @@ static int uea_boot(struct uea_softc *sc)
 	if (!intr) {
 		uea_err(INS_TO_USBDEV(sc),
 		       "cannot allocate interrupt package\n");
-		uea_leaves(INS_TO_USBDEV(sc));
-		return -ENOMEM;
+		goto err0;
 	}
 
 	sc->urb_int = usb_alloc_urb(0, GFP_KERNEL);
 	if (!sc->urb_int) {
 		uea_err(INS_TO_USBDEV(sc), "cannot allocate interrupt URB\n");
-		goto err;
+		goto err1;
 	}
 
 	usb_fill_int_urb(sc->urb_int, sc->usb_dev,
@@ -2144,7 +2151,7 @@ static int uea_boot(struct uea_softc *sc)
 	if (ret < 0) {
 		uea_err(INS_TO_USBDEV(sc),
 		       "urb submition failed with error %d\n", ret);
-		goto err;
+		goto err1;
 	}
 
 	sc->kthread = kthread_run(uea_kthread, sc, "ueagle-atm");
@@ -2158,10 +2165,12 @@ static int uea_boot(struct uea_softc *sc)
 
 err2:
 	usb_kill_urb(sc->urb_int);
-err:
+err1:
 	usb_free_urb(sc->urb_int);
 	sc->urb_int = NULL;
 	kfree(intr);
+err0:
+	destroy_workqueue(sc->work_q);
 	uea_leaves(INS_TO_USBDEV(sc));
 	return -ENOMEM;
 }
@@ -2176,15 +2185,15 @@ static void uea_stop(struct uea_softc *sc)
 	ret = kthread_stop(sc->kthread);
 	uea_dbg(INS_TO_USBDEV(sc), "kthread finish with status %d\n", ret);
 
-	/* stop any pending boot process */
-	flush_scheduled_work();
-
 	uea_request(sc, UEA_SET_MODE, UEA_LOOPBACK_ON, 0, NULL);
 
 	usb_kill_urb(sc->urb_int);
 	kfree(sc->urb_int->transfer_buffer);
 	usb_free_urb(sc->urb_int);
 
+	/* stop any pending boot process, when no one can schedule work */
+	destroy_workqueue(sc->work_q);
+
 	if (sc->dsp_firm)
 		release_firmware(sc->dsp_firm);
 	uea_leaves(INS_TO_USBDEV(sc));