Merge tag 'v4.13-rc1' into patchwork

Linux v4.13-rc1

* tag 'v4.13-rc1': (11136 commits)
  Linux v4.13-rc1
  random: reorder READ_ONCE() in get_random_uXX
  random: suppress spammy warnings about unseeded randomness
  replace incorrect strscpy use in FORTIFY_SOURCE
  kmod: throttle kmod thread limit
  kmod: add test driver to stress test the module loader
  MAINTAINERS: give kmod some maintainer love
  xtensa: use generic fb.h
  fault-inject: add /proc/<pid>/fail-nth
  fault-inject: simplify access check for fail-nth
  fault-inject: make fail-nth read/write interface symmetric
  fault-inject: parse as natural 1-based value for fail-nth write interface
  fault-inject: automatically detect the number base for fail-nth write interface
  kernel/watchdog.c: use better pr_fmt prefix
  MAINTAINERS: move the befs tree to kernel.org
  lib/atomic64_test.c: add a test that atomic64_inc_not_zero() returns an int
  mm: fix overflow check in expand_upwards()
  ubifs: Set double hash cookie also for RENAME_EXCHANGE
  ubifs: Massage assert in ubifs_xattr_set() wrt. init_xattrs
  ubifs: Don't leak kernel memory to the MTD
  ...

1 files changed, 7 insertions, 0 deletions

diff --git a/Documentation/serial/n_gsm.txt b/Documentation/serial/n_gsm.txt
index a5d91126a8f7..875361bb7cb4 100644
--- a/Documentation/serial/n_gsm.txt
+++ b/Documentation/serial/n_gsm.txt
@@ -77,6 +77,13 @@ for example, it's possible :
 
 6- first close all virtual ports before closing the physical port.
 
+Note that after closing the physical port the modem is still in multiplexing
+mode. This may prevent a successful re-opening of the port later. To avoid
+this situation either reset the modem if your hardware allows that or send
+a disconnect command frame manually before initializing the multiplexing mode
+for the second time. The byte sequence for the disconnect command frame is:
+0xf9, 0x03, 0xef, 0x03, 0xc3, 0x16, 0xf9.
+
 Additional Documentation
 ------------------------
 More practical details on the protocol and how it's supported by industrial