TTY/Serial driver fixes for 5.19-rc3

Here are some small tty and serial driver fixes for 5.19-rc3 to resolve
 some reported problems:
 	- 8250 lsr read bugfix
 	- n_gsm line discipline allocation fix
 	- qcom serial driver fix for reported lockups that happened in
 	  -rc1
 	- goldfish tty driver fix
 
 All have been in linux-next for a while now with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are some small tty and serial driver fixes for 5.19-rc3 to
  resolve some reported problems:

   - 8250 lsr read bugfix

   - n_gsm line discipline allocation fix

   - qcom serial driver fix for reported lockups that happened in -rc1

   - goldfish tty driver fix

  All have been in linux-next for a while now with no reported issues"

* tag 'tty-5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250: Store to lsr_save_flags after lsr read
  tty: goldfish: Fix free_irq() on remove
  tty: serial: qcom-geni-serial: Implement start_rx callback
  serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.
  tty: n_gsm: Debug output allocation must use GFP_ATOMIC

drivers/tty/goldfish.c

@@ -426,7 +426,7 @@ static int goldfish_tty_remove(struct platform_device *pdev)
 	tty_unregister_device(goldfish_tty_driver, qtty->console.index);
 	iounmap(qtty->base);
 	qtty->base = NULL;
-	free_irq(qtty->irq, pdev);
+	free_irq(qtty->irq, qtty);
 	tty_port_destroy(&qtty->port);
 	goldfish_tty_current_line_count--;
 	if (goldfish_tty_current_line_count == 0)

drivers/tty/n_gsm.c

@@ -455,7 +455,7 @@ static void gsm_hex_dump_bytes(const char *fname, const u8 *data,
 		return;
 	}
 
-	prefix = kasprintf(GFP_KERNEL, "%s: ", fname);
+	prefix = kasprintf(GFP_ATOMIC, "%s: ", fname);
 	if (!prefix)
 		return;
 	print_hex_dump(KERN_INFO, prefix, DUMP_PREFIX_OFFSET, 16, 1, data, len,

drivers/tty/serial/8250/8250_port.c

@@ -1517,6 +1517,8 @@ static inline void __stop_tx(struct uart_8250_port *p)
 		unsigned char lsr = serial_in(p, UART_LSR);
 		u64 stop_delay = 0;
 
+		p->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
+
 		if (!(lsr & UART_LSR_THRE))
 			return;
 		/*

drivers/tty/serial/qcom_geni_serial.c

@@ -1306,6 +1306,7 @@ static const struct uart_ops qcom_geni_console_pops = {
 	.stop_tx = qcom_geni_serial_stop_tx,
 	.start_tx = qcom_geni_serial_start_tx,
 	.stop_rx = qcom_geni_serial_stop_rx,
+	.start_rx = qcom_geni_serial_start_rx,
 	.set_termios = qcom_geni_serial_set_termios,
 	.startup = qcom_geni_serial_startup,
 	.request_port = qcom_geni_serial_request_port,

drivers/tty/serial/serial_core.c

@@ -2214,11 +2214,12 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 	/*
 	 * Nothing to do if the console is not suspending
 	 * except stop_rx to prevent any asynchronous data
-	 * over RX line. Re-start_rx, when required, is
-	 * done by set_termios in resume sequence
+	 * over RX line. However ensure that we will be
+	 * able to Re-start_rx later.
 	 */
 	if (!console_suspend_enabled && uart_console(uport)) {
-		uport->ops->stop_rx(uport);
+		if (uport->ops->start_rx)
+			uport->ops->stop_rx(uport);
 		goto unlock;
 	}
 
@@ -2310,6 +2311,8 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 		if (console_suspend_enabled)
 			uart_change_pm(state, UART_PM_STATE_ON);
 		uport->ops->set_termios(uport, &termios, NULL);
+		if (!console_suspend_enabled && uport->ops->start_rx)
+			uport->ops->start_rx(uport);
 		if (console_suspend_enabled)
 			console_start(uport->cons);
 	}

include/linux/serial_core.h

@@ -45,6 +45,7 @@ struct uart_ops {
 	void		(*unthrottle)(struct uart_port *);
 	void		(*send_xchar)(struct uart_port *, char ch);
 	void		(*stop_rx)(struct uart_port *);
+	void		(*start_rx)(struct uart_port *);
 	void		(*enable_ms)(struct uart_port *);
 	void		(*break_ctl)(struct uart_port *, int ctl);
 	int		(*startup)(struct uart_port *);