Merge tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the large TTY/Serial driver set of patches for 4.21-rc1.

  A number of small serial driver changes along with some good tty core
  fixes for long-reported issues with locking. There is also a new
  console font added to the tree, for high-res screens, so that should
  be helpful for many.

  The last patch in the series is a revert of an older one in the tree,
  it came late but it resolves a reported issue that linux-next was
  having for some people.

  Full details are in the shortlog, and all of these, with the exception
  of the revert, have been in linux-next for a while with no reported
  issues"

* tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (85 commits)
  Revert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250"
  serial: sccnxp: Allow to use non-standard baud rates
  serial: sccnxp: Adds a delay between sequential read/write cycles
  tty: serial: qcom_geni_serial: Fix UART hang
  tty: serial: qcom_geni_serial: Fix wrap around of TX buffer
  serial: max310x: Fix tx_empty() callback
  dt-bindings: serial: sh-sci: Document r8a774c0 bindings
  dt-bindings: serial: sh-sci: Document r8a774a1 bindings
  Fonts: New Terminus large console font
  dt-bindings: serial: lpuart: add imx8qxp compatible string
  serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly
  serial: uartps: Fix error path when alloc failed
  serial: uartps: Check if the device is a console
  serial: uartps: Add the device_init_wakeup
  tty: serial: samsung: Increase maximum baudrate
  tty: serial: samsung: Properly set flags in autoCTS mode
  tty: Use of_node_name_{eq,prefix} for node name comparisons
  tty/serial: do not free trasnmit buffer page under port lock
  serial: 8250: Rate limit serial port rx interrupts during input overruns
  dt-bindings: serial: 8250: Add rate limit for serial port input overruns
  ...

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/tty.h b/include/linux/tty.h
index 392138fe59b6..bfa4e2ee94a9 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -366,6 +366,7 @@ struct tty_file_private {
 #define TTY_NO_WRITE_SPLIT 	17	/* Preserve write boundaries to driver */
 #define TTY_HUPPED 		18	/* Post driver->hangup() */
 #define TTY_HUPPING		19	/* Hangup in progress */
+#define TTY_LDISC_CHANGING	20	/* Change pending - non-block IO */
 #define TTY_LDISC_HALTED	22	/* Line discipline is halted */
 
 /* Values for tty->flow_change */
@@ -383,6 +384,12 @@ static inline void tty_set_flow_change(struct tty_struct *tty, int val)
 	smp_mb();
 }
 
+static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
+{
+	return file->f_flags & O_NONBLOCK ||
+		test_bit(TTY_LDISC_CHANGING, &tty->flags);
+}
+
 static inline bool tty_io_error(struct tty_struct *tty)
 {
 	return test_bit(TTY_IO_ERROR, &tty->flags);