releases/4.6.1/acpi-osi-fix-an-issue-that-acpi_osi-cannot-disable-acpica-internal-strings.patch

   1 From 30c9bb0d7603e7b3f4d6a0ea231e1cddae020c32 Mon Sep 17 00:00:00 2001
   2 From: Lv Zheng <lv.zheng@intel.com>
   3 Date: Tue, 3 May 2016 16:48:20 +0800
   4 Subject: ACPI / osi: Fix an issue that acpi_osi=!* cannot disable ACPICA internal strings
   5
   6 From: Lv Zheng <lv.zheng@intel.com>
   7
   8 commit 30c9bb0d7603e7b3f4d6a0ea231e1cddae020c32 upstream.
   9
  10 The order of the _OSI related functionalities is as follows:
  11
  12   acpi_blacklisted()
  13     acpi_dmi_osi_linux()
  14       acpi_osi_setup()
  15     acpi_osi_setup()
  16       acpi_update_interfaces() if "!*"
  17       <<<<<<<<<<<<<<<<<<<<<<<<
  18   parse_args()
  19     __setup("acpi_osi=")
  20       acpi_osi_setup_linux()
  21         acpi_update_interfaces() if "!*"
  22         <<<<<<<<<<<<<<<<<<<<<<<<
  23   acpi_early_init()
  24     acpi_initialize_subsystem()
  25       acpi_ut_initialize_interfaces()
  26       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  27   acpi_bus_init()
  28     acpi_os_initialize1()
  29       acpi_install_interface_handler(acpi_osi_handler)
  30       acpi_osi_setup_late()
  31         acpi_update_interfaces() for "!"
  32         >>>>>>>>>>>>>>>>>>>>>>>>
  33   acpi_osi_handler()
  34
  35 Since acpi_osi_setup_linux() can override acpi_dmi_osi_linux(), the command
  36 line setting can override the DMI detection. That's why acpi_blacklisted()
  37 is put before __setup("acpi_osi=").
  38
  39 Then we can notice the following wrong invocation order. There are
  40 acpi_update_interfaces() (marked by <<<<) calls invoked before
  41 acpi_ut_initialize_interfaces() (marked by ^^^^). This makes it impossible
  42 to use acpi_osi=!* correctly from OSI DMI table or from the command line.
  43 The use of acpi_osi=!* is meant to disable both ACPICA
  44 (acpi_gbl_supported_interfaces) and Linux specific strings
  45 (osi_setup_entries) while the ACPICA part should have stopped working
  46 because of the order issue.
  47
  48 This patch fixes this issue by moving acpi_update_interfaces() to where
  49 it is invoked for acpi_osi=! (marked by >>>>) as this is ensured to be
  50 invoked after acpi_ut_initialize_interfaces() (marked by ^^^^). Linux
  51 specific strings are still handled in the original place in order to make
  52 the following command line working: acpi_osi=!* acpi_osi="Module Device".
  53
  54 Note that since acpi_osi=!* is meant to further disable linux specific
  55 string comparing to the acpi_osi=!, there is no such use case in our bug
  56 fixing work and hence there is no one using acpi_osi=!* either from the
  57 command line or from the DMI quirks, this issue is just a theoretical
  58 issue.
  59
  60 Fixes: 741d81280ad2 (ACPI: Add facility to remove all _OSI strings)
  61 Tested-by: Lukas Wunner <lukas@wunner.de>
  62 Tested-by: Chen Yu <yu.c.chen@intel.com>
  63 Signed-off-by: Lv Zheng <lv.zheng@intel.com>
  64 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  65 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  66
  67 ---
  68  drivers/acpi/osl.c |   16 +++++++++++-----
  69  1 file changed, 11 insertions(+), 5 deletions(-)
  70
  71 --- a/drivers/acpi/osl.c
  72 +++ b/drivers/acpi/osl.c
  73 @@ -135,7 +135,7 @@ static struct osi_linux {
  74         unsigned int    enable:1;
  75         unsigned int    dmi:1;
  76         unsigned int    cmdline:1;
  77 -       unsigned int    default_disabling:1;
  78 +       u8              default_disabling;
  79  } osi_linux = {0, 0, 0, 0};
  80
  81  static u32 acpi_osi_handler(acpi_string interface, u32 supported)
  82 @@ -1751,10 +1751,13 @@ void __init acpi_osi_setup(char *str)
  83         if (*str == '!') {
  84                 str++;
  85                 if (*str == '\0') {
  86 -                       osi_linux.default_disabling = 1;
  87 +                       /* Do not override acpi_osi=!* */
  88 +                       if (!osi_linux.default_disabling)
  89 +                               osi_linux.default_disabling =
  90 +                                       ACPI_DISABLE_ALL_VENDOR_STRINGS;
  91                         return;
  92                 } else if (*str == '*') {
  93 -                       acpi_update_interfaces(ACPI_DISABLE_ALL_STRINGS);
  94 +                       osi_linux.default_disabling = ACPI_DISABLE_ALL_STRINGS;
  95                         for (i = 0; i < OSI_STRING_ENTRIES_MAX; i++) {
  96                                 osi = &osi_setup_entries[i];
  97                                 osi->enable = false;
  98 @@ -1827,10 +1830,13 @@ static void __init acpi_osi_setup_late(v
  99         acpi_status status;
 100
 101         if (osi_linux.default_disabling) {
 102 -               status = acpi_update_interfaces(ACPI_DISABLE_ALL_VENDOR_STRINGS);
 103 +               status = acpi_update_interfaces(osi_linux.default_disabling);
 104
 105                 if (ACPI_SUCCESS(status))
 106 -                       printk(KERN_INFO PREFIX "Disabled all _OSI OS vendors\n");
 107 +                       printk(KERN_INFO PREFIX "Disabled all _OSI OS vendors%s\n",
 108 +                               osi_linux.default_disabling ==
 109 +                               ACPI_DISABLE_ALL_STRINGS ?
 110 +                               " and feature groups" : "");
 111         }
 112
 113         for (i = 0; i < OSI_STRING_ENTRIES_MAX; i++) {