cdc-acm: implement put_char() and flush_chars() (a81cf979) · Commits · 戴 / test

drivers/usb/class/cdc-acm.c

+67 −0

Original line number	Diff line number	Diff line
		@@ -713,9 +713,20 @@ static int acm_tty_write(struct tty_struct *tty,
		}

		if (acm->susp_count) {
		if (acm->putbuffer) {
		/* now to preserve order */
		usb_anchor_urb(acm->putbuffer->urb, &acm->delayed);
		acm->putbuffer = NULL;
		}
		usb_anchor_urb(wb->urb, &acm->delayed);
		spin_unlock_irqrestore(&acm->write_lock, flags);
		return count;
		} else {
		if (acm->putbuffer) {
		/* at this point there is no good way to handle errors */
		acm_start_wb(acm, acm->putbuffer);
		acm->putbuffer = NULL;
		}
		}

		stat = acm_start_wb(acm, wb);
		@@ -726,6 +737,60 @@ static int acm_tty_write(struct tty_struct *tty,
		return count;
		}

		static void acm_tty_flush_chars(struct tty_struct *tty)
		{
		struct acm *acm = tty->driver_data;
		struct acm_wb *cur = acm->putbuffer;
		int err;
		unsigned long flags;

		acm->putbuffer = NULL;
		err = usb_autopm_get_interface_async(acm->control);
		spin_lock_irqsave(&acm->write_lock, flags);
		if (err < 0) {
		cur->use = 0;
		goto out;
		}

		if (acm->susp_count)
		usb_anchor_urb(cur->urb, &acm->delayed);
		else
		acm_start_wb(acm, cur);
		out:
		spin_unlock_irqrestore(&acm->write_lock, flags);
		return;
		}

		static int acm_tty_put_char(struct tty_struct *tty, unsigned char ch)
		{
		struct acm *acm = tty->driver_data;
		struct acm_wb *cur;
		int wbn;
		unsigned long flags;

		overflow:
		cur = acm->putbuffer;
		if (!cur) {
		spin_lock_irqsave(&acm->write_lock, flags);
		wbn = acm_wb_alloc(acm);
		if (wbn >= 0) {
		cur = &acm->wb[wbn];
		acm->putbuffer = cur;
		}
		spin_unlock_irqrestore(&acm->write_lock, flags);
		if (!cur)
		return 0;
		}

		if (cur->len == acm->writesize) {
		acm_tty_flush_chars(tty);
		goto overflow;
		}

		cur->buf[cur->len++] = ch;
		return 1;
		}

		static int acm_tty_write_room(struct tty_struct *tty)
		{
		struct acm *acm = tty->driver_data;
		@@ -1905,6 +1970,8 @@ static const struct tty_operations acm_ops = {
		.cleanup = acm_tty_cleanup,
		.hangup = acm_tty_hangup,
		.write = acm_tty_write,
		.put_char = acm_tty_put_char,
		.flush_chars = acm_tty_flush_chars,
		.write_room = acm_tty_write_room,
		.ioctl = acm_tty_ioctl,
		.throttle = acm_tty_throttle,

drivers/usb/class/cdc-acm.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -94,6 +94,7 @@ struct acm {
		unsigned long read_urbs_free;
		struct urb *read_urbs[ACM_NR];
		struct acm_rb read_buffers[ACM_NR];
		struct acm_wb putbuffer; / for acm_tty_put_char() */
		int rx_buflimit;
		int rx_endpoint;
		spinlock_t read_lock;

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