src/patches/suse-2.6.27.25/patches.arch/acpi_thinkpad_introduce_acpi_root_table_boot_param.patch

   1 From: Thomas Renninger <trenn@suse.de>
   2 Subject: Introduce acpi_root_table=rsdt boot param and dmi list to force rsdt
   3 Patch-mainline: not yet
   4 References: http://bugzilla.kernel.org/show_bug.cgi?id=8246
   5
   6 This one is part of a patch series:
   7 acpi_thinkpad_introduce_acpi_root_table_boot_param.patch
   8 acpi_thinkpad_introduce_acpica_rsdt_global_variable.patch
   9 acpi_thinkpad_remove_R40e_c-state_blacklist.patch
  10
  11 Blacklist R40e, R51e and T40, T40p, T41, T41p, T42, T42p, R50 and R50p
  12 ThinkPads to use the RSDT instead of the XSDT.
  13
  14 Signed-off-by: Thomas Renninger <trenn@suse.de>
  15 Tested-by: Mark Doughty <me@markdoughty.co.uk>
  16 CC: Yakui Zhao <yakui.zhao@intel.com>
  17
  18 ---
  19  Documentation/kernel-parameters.txt |    5 ++++
  20  drivers/acpi/tables.c               |   37 ++++++++++++++++++++++++++++++++++++
  21  2 files changed, 42 insertions(+)
  22
  23 --- a/Documentation/kernel-parameters.txt
  24 +++ b/Documentation/kernel-parameters.txt
  25 @@ -237,6 +237,11 @@ and is between 256 and 4096 characters.
  26                         to assume that this machine's pmtimer latches its value
  27                         and always returns good values.
  28
  29 +       acpi_root_table= [X86,ACPI]
  30 +                       { rsdt }
  31 +                       rsdt: Take RSDT address for fetching
  32 +                       ACPI tables (instead of XSDT)
  33 +
  34         agp=            [AGP]
  35                         { off | try_unsupported }
  36                         off: disable AGP support
  37 --- a/drivers/acpi/tables.c
  38 +++ b/drivers/acpi/tables.c
  39 @@ -32,6 +32,7 @@
  40  #include <linux/errno.h>
  41  #include <linux/acpi.h>
  42  #include <linux/bootmem.h>
  43 +#include <linux/dmi.h>
  44
  45  #define PREFIX                 "ACPI: "
  46
  47 @@ -282,6 +283,37 @@ static void __init check_multiple_madt(v
  48         return;
  49  }
  50
  51 +static struct dmi_system_id __initdata acpi_rsdt_dmi_table[] = {
  52 +       {
  53 +           .ident = "ThinkPad ", /* R40e, broken C-states */
  54 +           .matches = {
  55 +               DMI_MATCH(DMI_BIOS_VENDOR, "IBM"),
  56 +               DMI_MATCH(DMI_BIOS_VERSION, "1SET")},
  57 +       },
  58 +       {
  59 +           .ident = "ThinkPad ", /* R50e, slow booting */
  60 +           .matches = {
  61 +               DMI_MATCH(DMI_BIOS_VENDOR, "IBM"),
  62 +               DMI_MATCH(DMI_BIOS_VERSION, "1WET")},
  63 +       },
  64 +       {
  65 +           .ident = "ThinkPad ", /* T40, T40p, T41, T41p, T42, T42p
  66 +                                    R50, R50p */
  67 +           .matches = {
  68 +               DMI_MATCH(DMI_BIOS_VENDOR, "IBM"),
  69 +               DMI_MATCH(DMI_BIOS_VERSION, "1RET")},
  70 +       },
  71 +       {}
  72 +};
  73 +
  74 +static int __init acpi_force_rsdt(char *opt)
  75 +{
  76 +       if (!strcmp(opt, "rsdt"))
  77 +               acpi_gbl_force_rsdt = 1;
  78 +       return 0;
  79 +}
  80 +early_param("acpi_root_table", acpi_force_rsdt);
  81 +
  82  /*
  83   * acpi_table_init()
  84   *
  85 @@ -295,6 +327,11 @@ int __init acpi_table_init(void)
  86  {
  87         acpi_status status;
  88
  89 +       if (dmi_check_system(acpi_rsdt_dmi_table))
  90 +               acpi_gbl_force_rsdt = 1;
  91 +       if (acpi_gbl_force_rsdt)
  92 +               printk(KERN_INFO "Using RSDT as ACPI root table\n");
  93 +
  94         status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
  95         if (ACPI_FAILURE(status))
  96                 return 1;