add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/drivers/usb/serial/generic.c
..
..
@@ -106,12 +106,8 @@
106
106
 int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
107
107
 {
108
108
 	int result = 0;
109
-	unsigned long flags;
110
109
 
111
-	spin_lock_irqsave(&port->lock, flags);
112
-	port->throttled = 0;
113
-	port->throttle_req = 0;
114
-	spin_unlock_irqrestore(&port->lock, flags);
110
+	clear_bit(USB_SERIAL_THROTTLED, &port->flags);
115
111
 
116
112
 	if (port->bulk_in_size)
117
113
 		result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
..
..
@@ -349,7 +345,7 @@
349
345
 void usb_serial_generic_process_read_urb(struct urb *urb)
350
346
 {
351
347
 	struct usb_serial_port *port = urb->context;
352
-	char *ch = (char *)urb->transfer_buffer;
348
+	char *ch = urb->transfer_buffer;
353
349
 	int i;
354
350
 
355
351
 	if (!urb->actual_length)
..
..
@@ -359,13 +355,13 @@
359
355
 	 * stuff like 3G modems, so shortcircuit it in the 99.9999999% of
360
356
 	 * cases where the USB serial is not a console anyway.
361
357
 	 */
362
-	if (!port->port.console || !port->sysrq) {
363
-		tty_insert_flip_string(&port->port, ch, urb->actual_length);
364
-	} else {
358
+	if (port->sysrq) {
365
359
 		for (i = 0; i < urb->actual_length; i++, ch++) {
366
360
 			if (!usb_serial_handle_sysrq_char(port, *ch))
367
361
 				tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
368
362
 		}
363
+	} else {
364
+		tty_insert_flip_string(&port->port, ch, urb->actual_length);
369
365
 	}
370
366
 	tty_flip_buffer_push(&port->port);
371
367
 }
..
..
@@ -375,7 +371,6 @@
375
371
 {
376
372
 	struct usb_serial_port *port = urb->context;
377
373
 	unsigned char *data = urb->transfer_buffer;
378
-	unsigned long flags;
379
374
 	bool stopped = false;
380
375
 	int status = urb->status;
381
376
 	int i;
..
..
@@ -422,22 +417,17 @@
422
417
 	/*
423
418
 	 * Make sure URB is marked as free before checking the throttled flag
424
419
 	 * to avoid racing with unthrottle() on another CPU. Matches the
425
-	 * smp_mb() in unthrottle().
420
+	 * smp_mb__after_atomic() in unthrottle().
426
421
 	 */
427
422
 	smp_mb__after_atomic();
428
423
 
429
424
 	if (stopped)
430
425
 		return;
431
426
 
432
-	/* Throttle the device if requested by tty */
433
-	spin_lock_irqsave(&port->lock, flags);
434
-	port->throttled = port->throttle_req;
435
-	if (!port->throttled) {
436
-		spin_unlock_irqrestore(&port->lock, flags);
437
-		usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
438
-	} else {
439
-		spin_unlock_irqrestore(&port->lock, flags);
440
-	}
427
+	if (test_bit(USB_SERIAL_THROTTLED, &port->flags))
428
+		return;
429
+
430
+	usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
441
431
 }
442
432
 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
443
433
 
..
..
@@ -473,10 +463,9 @@
473
463
 	default:
474
464
 		dev_err_console(port, "%s - nonzero urb status: %d\n",
475
465
 							__func__, status);
476
-		goto resubmit;
466
+		break;
477
467
 	}
478
468
 
479
-resubmit:
480
469
 	usb_serial_generic_write_start(port, GFP_ATOMIC);
481
470
 	usb_serial_port_softint(port);
482
471
 }
..
..
@@ -485,32 +474,24 @@
485
474
 void usb_serial_generic_throttle(struct tty_struct *tty)
486
475
 {
487
476
 	struct usb_serial_port *port = tty->driver_data;
488
-	unsigned long flags;
489
477
 
490
-	spin_lock_irqsave(&port->lock, flags);
491
-	port->throttle_req = 1;
492
-	spin_unlock_irqrestore(&port->lock, flags);
478
+	set_bit(USB_SERIAL_THROTTLED, &port->flags);
493
479
 }
494
480
 EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
495
481
 
496
482
 void usb_serial_generic_unthrottle(struct tty_struct *tty)
497
483
 {
498
484
 	struct usb_serial_port *port = tty->driver_data;
499
-	int was_throttled;
500
485
 
501
-	spin_lock_irq(&port->lock);
502
-	was_throttled = port->throttled;
503
-	port->throttled = port->throttle_req = 0;
504
-	spin_unlock_irq(&port->lock);
486
+	clear_bit(USB_SERIAL_THROTTLED, &port->flags);
505
487
 
506
488
 	/*
507
489
 	 * Matches the smp_mb__after_atomic() in
508
490
 	 * usb_serial_generic_read_bulk_callback().
509
491
 	 */
510
-	smp_mb();
492
+	smp_mb__after_atomic();
511
493
 
512
-	if (was_throttled)
513
-		usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
494
+	usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
514
495
 }
515
496
 EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
516
497
 
..
..
@@ -590,10 +571,10 @@
590
571
 }
591
572
 EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount);
592
573
 
593
-#ifdef CONFIG_MAGIC_SYSRQ
574
+#if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
594
575
 int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
595
576
 {
596
-	if (port->sysrq && port->port.console) {
577
+	if (port->sysrq) {
597
578
 		if (ch && time_before(jiffies, port->sysrq)) {
598
579
 			handle_sysrq(ch);
599
580
 			port->sysrq = 0;
..
..
@@ -603,16 +584,13 @@
603
584
 	}
604
585
 	return 0;
605
586
 }
606
-#else
607
-int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
608
-{
609
-	return 0;
610
-}
611
-#endif
612
587
 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
613
588
 
614
589
 int usb_serial_handle_break(struct usb_serial_port *port)
615
590
 {
591
+	if (!port->port.console)
592
+		return 0;
593
+
616
594
 	if (!port->sysrq) {
617
595
 		port->sysrq = jiffies + HZ*5;
618
596
 		return 1;
..
..
@@ -621,6 +599,7 @@
621
599
 	return 0;
622
600
 }
623
601
 EXPORT_SYMBOL_GPL(usb_serial_handle_break);
602
+#endif
624
603
 
625
604
 /**
626
605
  * usb_serial_handle_dcd_change - handle a change of carrier detect state
..
..
@@ -628,12 +607,10 @@
628
607
  * @tty: tty for the port
629
608
  * @status: new carrier detect status, nonzero if active
630
609
  */
631
-void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
610
+void usb_serial_handle_dcd_change(struct usb_serial_port *port,
632
611
 				struct tty_struct *tty, unsigned int status)
633
612
 {
634
-	struct tty_port *port = &usb_port->port;
635
-
636
-	dev_dbg(&usb_port->dev, "%s - status %d\n", __func__, status);
613
+	dev_dbg(&port->dev, "%s - status %d\n", __func__, status);
637
614
 
638
615
 	if (tty) {
639
616
 		struct tty_ldisc *ld = tty_ldisc_ref(tty);
..
..
@@ -646,7 +623,7 @@
646
623
 	}
647
624
 
648
625
 	if (status)
649
-		wake_up_interruptible(&port->open_wait);
626
+		wake_up_interruptible(&port->port.open_wait);
650
627
 	else if (tty && !C_CLOCAL(tty))
651
628
 		tty_hangup(tty);
652
629
 }