Merge tag 'tty-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the large tty/serial patchset for 4.13-rc1.

  A lot of tty and serial driver updates are in here, along with some
  fixups for some __get/put_user usages that were reported. Nothing
  huge, just lots of development by a number of different developers,
  full details in the shortlog.

  All of these have been in linux-next for a while"

* tag 'tty-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (71 commits)
  tty: serial: lpuart: add a more accurate baud rate calculation method
  tty: serial: lpuart: add earlycon support for imx7ulp
  tty: serial: lpuart: add imx7ulp support
  dt-bindings: serial: fsl-lpuart: add i.MX7ULP support
  tty: serial: lpuart: add little endian 32 bit register support
  tty: serial: lpuart: refactor lpuart32_{read|write} prototype
  tty: serial: lpuart: introduce lpuart_soc_data to represent SoC property
  serial: imx-serial - move DMA buffer configuration to DT
  serial: imx: Enable RTSD only when needed
  serial: imx: Remove unused members from imx_port struct
  serial: 8250: 8250_omap: Fix race b/w dma completion and RX timeout
  serial: 8250: Fix THRE flag usage for CAP_MINI
  tty/serial: meson_uart: update to stable bindings
  dt-bindings: serial: Add bindings for the Amlogic Meson UARTs
  serial: Delete dead code for CIR serial ports
  serial: sirf: make of_device_ids const
  serial/mpsc: switch to dma_alloc_attrs
  tty: serial: Add Actions Semi Owl UART earlycon
  dt-bindings: serial: Document Actions Semi Owl UARTs
  tty/serial: atmel: make the driver DT only
  ...

1 files changed, 35 insertions, 19 deletions

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 2667a205a5ab..363a8ca824ad 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2015,6 +2015,33 @@ static void gsm_error(struct gsm_mux *gsm,
 	gsm->io_error++;
 }
 
+static int gsm_disconnect(struct gsm_mux *gsm)
+{
+	struct gsm_dlci *dlci = gsm->dlci[0];
+	struct gsm_control *gc;
+
+	if (!dlci)
+		return 0;
+
+	/* In theory disconnecting DLCI 0 is sufficient but for some
+	   modems this is apparently not the case. */
+	gc = gsm_control_send(gsm, CMD_CLD, NULL, 0);
+	if (gc)
+		gsm_control_wait(gsm, gc);
+
+	del_timer_sync(&gsm->t2_timer);
+	/* Now we are sure T2 has stopped */
+
+	gsm_dlci_begin_close(dlci);
+	wait_event_interruptible(gsm->event,
+				dlci->state == DLCI_CLOSED);
+
+	if (signal_pending(current))
+		return -EINTR;
+
+	return 0;
+}
+
 /**
  *	gsm_cleanup_mux		-	generic GSM protocol cleanup
  *	@gsm: our mux
@@ -2029,7 +2056,6 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm)
 	int i;
 	struct gsm_dlci *dlci = gsm->dlci[0];
 	struct gsm_msg *txq, *ntxq;
-	struct gsm_control *gc;
 
 	gsm->dead = 1;
 
@@ -2045,21 +2071,11 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm)
 	if (i == MAX_MUX)
 		return;
 
-	/* In theory disconnecting DLCI 0 is sufficient but for some
-	   modems this is apparently not the case. */
-	if (dlci) {
-		gc = gsm_control_send(gsm, CMD_CLD, NULL, 0);
-		if (gc)
-			gsm_control_wait(gsm, gc);
-	}
 	del_timer_sync(&gsm->t2_timer);
 	/* Now we are sure T2 has stopped */
-	if (dlci) {
+	if (dlci)
 		dlci->dead = 1;
-		gsm_dlci_begin_close(dlci);
-		wait_event_interruptible(gsm->event,
-					dlci->state == DLCI_CLOSED);
-	}
+
 	/* Free up any link layer users */
 	mutex_lock(&gsm->mutex);
 	for (i = 0; i < NUM_DLCI; i++)
@@ -2519,12 +2535,12 @@ static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm,
 	 */
 
 	if (need_close || need_restart) {
-		gsm_dlci_begin_close(gsm->dlci[0]);
-		/* This will timeout if the link is down due to N2 expiring */
-		wait_event_interruptible(gsm->event,
-				gsm->dlci[0]->state == DLCI_CLOSED);
-		if (signal_pending(current))
-			return -EINTR;
+		int ret;
+
+		ret = gsm_disconnect(gsm);
+
+		if (ret)
+			return ret;
 	}
 	if (need_restart)
 		gsm_cleanup_mux(gsm);