queue-4.19/sunhv-fix-device-naming-inconsistency-between-sunhv_.patch

   1 From 837cc34fcc298696326f1bd3d4e919d65f81e0b5 Mon Sep 17 00:00:00 2001
   2 From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
   3 Date: Tue, 11 Jun 2019 17:38:37 +0200
   4 Subject: sunhv: Fix device naming inconsistency between sunhv_console and
   5  sunhv_reg
   6
   7 [ Upstream commit 07a6d63eb1b54b5fb38092780fe618dfe1d96e23 ]
   8
   9 In d5a2aa24, the name in struct console sunhv_console was changed from "ttyS"
  10 to "ttyHV" while the name in struct uart_ops sunhv_pops remained unchanged.
  11
  12 This results in the hypervisor console device to be listed as "ttyHV0" under
  13 /proc/consoles while the device node is still named "ttyS0":
  14
  15 root@osaka:~# cat /proc/consoles
  16 ttyHV0               -W- (EC p  )    4:64
  17 tty0                 -WU (E     )    4:1
  18 root@osaka:~# readlink /sys/dev/char/4:64
  19 ../../devices/root/f02836f0/f0285690/tty/ttyS0
  20 root@osaka:~#
  21
  22 This means that any userland code which tries to determine the name of the
  23 device file of the hypervisor console device can not rely on the information
  24 provided by /proc/consoles. In particular, booting current versions of debian-
  25 installer inside a SPARC LDOM will fail with the installer unable to determine
  26 the console device.
  27
  28 After renaming the device in struct uart_ops sunhv_pops to "ttyHV" as well,
  29 the inconsistency is fixed and it is possible again to determine the name
  30 of the device file of the hypervisor console device by reading the contents
  31 of /proc/console:
  32
  33 root@osaka:~# cat /proc/consoles
  34 ttyHV0               -W- (EC p  )    4:64
  35 tty0                 -WU (E     )    4:1
  36 root@osaka:~# readlink /sys/dev/char/4:64
  37 ../../devices/root/f02836f0/f0285690/tty/ttyHV0
  38 root@osaka:~#
  39
  40 With this change, debian-installer works correctly when installing inside
  41 a SPARC LDOM.
  42
  43 Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
  44 Signed-off-by: David S. Miller <davem@davemloft.net>
  45 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  46 ---
  47  drivers/tty/serial/sunhv.c | 2 +-
  48  1 file changed, 1 insertion(+), 1 deletion(-)
  49
  50 diff --git a/drivers/tty/serial/sunhv.c b/drivers/tty/serial/sunhv.c
  51 index 63e34d868de8..f8503f8fc44e 100644
  52 --- a/drivers/tty/serial/sunhv.c
  53 +++ b/drivers/tty/serial/sunhv.c
  54 @@ -397,7 +397,7 @@ static const struct uart_ops sunhv_pops = {
  55  static struct uart_driver sunhv_reg = {
  56         .owner                  = THIS_MODULE,
  57         .driver_name            = "sunhv",
  58 -       .dev_name               = "ttyS",
  59 +       .dev_name               = "ttyHV",
  60         .major                  = TTY_MAJOR,
  61  };
  62
  63 --
  64 2.20.1
  65