rejected/thinkpad_acpi-switch-Lenovo-BIOS-to-ACPI-backlight.patch

   1 From 32e3ffd1c4310efe205846ec125512a72357d499 Mon Sep 17 00:00:00 2001
   2 From: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
   3 Date: Tue, 8 Jan 2008 02:56:15 -0200
   4 Subject: ACPI: thinkpad-acpi: switch Lenovo BIOS to ACPI backlight mode
   5
   6 Lenovo ThinkPads with generic ACPI backlight level control can be easily
   7 set to react to keyboard brightness key presses in a more predictable way
   8 than what they do when in "DOS / bootloader" mode after Linux brings
   9 up the ACPI interface.
  10
  11 The switch to the ACPI backlight mode in the firmware is designed to be
  12 safe to use only as an one way trapdoor.  One is not to force the firmware
  13 to switch back to "DOS/bootloader" mode except by rebooting.  The mode
  14 switch itself is performed by calling any of the ACPI _BCL methods at least
  15 once.
  16
  17 When in ACPI mode, the backlight firmware just issues (standard) events for
  18 the brightness up/down hot key presses, and doesn't touch the hardware.
  19 thinkpad-acpi knows this, and will suppress issuing any backlight change
  20 notifications in the default keymap to avoid double-reporting.
  21
  22 Thus, provided userspace is sane, all should work (and *keep* working),
  23 which is more that can be said about the non-ACPI mode of the new Lenovo
  24 ThinkPad BIOSes when coupled to current userspace and X.org drivers.
  25
  26 Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
  27 ---
  28  drivers/misc/thinkpad_acpi.c |  123 +++++++++++++++++++++++-------------------
  29  1 files changed, 67 insertions(+), 56 deletions(-)
  30
  31 REJECT REASON: we need an acpi notification handle on the video device
  32 to get the ACPI events, at which point it is best to just tell the user
  33 to use the new ACPI video driver anyway.
  34
  35 diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
  36 index 7500c44..842aa07 100644
  37 --- a/drivers/misc/thinkpad_acpi.c
  38 +++ b/drivers/misc/thinkpad_acpi.c
  39 @@ -225,6 +225,7 @@ static struct {
  40         u32 light:1;
  41         u32 light_status:1;
  42         u32 bright_16levels:1;
  43 +       u32 bright_acpimode:1;
  44         u32 wan:1;
  45         u32 fan_ctrl_status_undef:1;
  46         u32 input_device_registered:1;
  47 @@ -2065,6 +2066,21 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
  48                                 TPACPI_HOTKEY_MAP_SIZE);
  49                 }
  50
  51 +               /* Do not issue duplicate brightness change events to
  52 +                * userspace */
  53 +               if (tp_features.bright_acpimode) {
  54 +                       printk(TPACPI_NOTICE
  55 +                              "Brightness hot keys firmware issues ACPI "
  56 +                              "video events\n");
  57 +                       printk(TPACPI_NOTICE
  58 +                              "Disabling brightness hot keys on event "
  59 +                              "device keymap\n");
  60 +                       hotkey_keycode_map[TP_ACPI_HOTKEYSCAN_FNHOME] =
  61 +                                                               KEY_RESERVED;
  62 +                       hotkey_keycode_map[TP_ACPI_HOTKEYSCAN_FNEND] =
  63 +                                                               KEY_RESERVED;
  64 +               }
  65 +
  66                 set_bit(EV_KEY, tpacpi_inputdev->evbit);
  67                 set_bit(EV_MSC, tpacpi_inputdev->evbit);
  68                 set_bit(MSC_SCAN, tpacpi_inputdev->mscbit);
  69 @@ -4272,7 +4288,7 @@ static struct backlight_ops ibm_backlight_data = {
  70
  71  /* --------------------------------------------------------------------- */
  72
  73 -static int __init tpacpi_query_bcll_levels(acpi_handle handle)
  74 +static int __init tpacpi_query_bcl_levels(acpi_handle handle)
  75  {
  76         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  77         union acpi_object *obj;
  78 @@ -4281,7 +4297,7 @@ static int __init tpacpi_query_bcll_levels(acpi_handle handle)
  79         if (ACPI_SUCCESS(acpi_evaluate_object(handle, NULL, NULL, &buffer))) {
  80                 obj = (union acpi_object *)buffer.pointer;
  81                 if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
  82 -                       printk(TPACPI_ERR "Unknown BCLL data, "
  83 +                       printk(TPACPI_ERR "Unknown _BCL data, "
  84                                "please report this to %s\n", TPACPI_MAIL);
  85                         rc = 0;
  86                 } else {
  87 @@ -4295,44 +4311,6 @@ static int __init tpacpi_query_bcll_levels(acpi_handle handle)
  88         return rc;
  89  }
  90
  91 -static acpi_status __init brightness_find_bcll(acpi_handle handle, u32 lvl,
  92 -                                       void *context, void **rv)
  93 -{
  94 -       char name[ACPI_PATH_SEGMENT_LENGTH];
  95 -       struct acpi_buffer buffer = { sizeof(name), &name };
  96 -
  97 -       if (ACPI_SUCCESS(acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer)) &&
  98 -           !strncmp("BCLL", name, sizeof(name) - 1)) {
  99 -               if (tpacpi_query_bcll_levels(handle) == 16) {
 100 -                       *rv = handle;
 101 -                       return AE_CTRL_TERMINATE;
 102 -               } else {
 103 -                       return AE_OK;
 104 -               }
 105 -       } else {
 106 -               return AE_OK;
 107 -       }
 108 -}
 109 -
 110 -static int __init brightness_check_levels(void)
 111 -{
 112 -       int status;
 113 -       void *found_node = NULL;
 114 -
 115 -       if (!vid_handle) {
 116 -               TPACPI_ACPIHANDLE_INIT(vid);
 117 -       }
 118 -       if (!vid_handle)
 119 -               return 0;
 120 -
 121 -       /* Search for a BCLL package with 16 levels */
 122 -       status = acpi_walk_namespace(ACPI_TYPE_PACKAGE, vid_handle, 3,
 123 -                                       brightness_find_bcll, NULL,
 124 -                                       &found_node);
 125 -
 126 -       return (ACPI_SUCCESS(status) && found_node != NULL);
 127 -}
 128 -
 129  static acpi_status __init brightness_find_bcl(acpi_handle handle, u32 lvl,
 130                                         void *context, void **rv)
 131  {
 132 @@ -4341,17 +4319,22 @@ static acpi_status __init brightness_find_bcl(acpi_handle handle, u32 lvl,
 133
 134         if (ACPI_SUCCESS(acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer)) &&
 135             !strncmp("_BCL", name, sizeof(name) - 1)) {
 136 -               *rv = handle;
 137 +               BUG_ON(!rv || !*rv);
 138 +               **(int **)rv = tpacpi_query_bcl_levels(handle);
 139                 return AE_CTRL_TERMINATE;
 140         } else {
 141                 return AE_OK;
 142         }
 143  }
 144
 145 +/*
 146 + * Returns 0 (no ACPI _BCL or _BCL invalid), or size of brightness map
 147 + */
 148  static int __init brightness_check_std_acpi_support(void)
 149  {
 150         int status;
 151 -       void *found_node = NULL;
 152 +       int bcl_levels = 0;
 153 +       void *bcl_ptr = &bcl_levels;
 154
 155         if (!vid_handle) {
 156                 TPACPI_ACPIHANDLE_INIT(vid);
 157 @@ -4359,11 +4342,21 @@ static int __init brightness_check_std_acpi_support(void)
 158         if (!vid_handle)
 159                 return 0;
 160
 161 -       /* Search for a _BCL method, but don't execute it */
 162 +       /*
 163 +        * Search for a _BCL method, and execute it.  This is safe on all
 164 +        * ThinkPads, and as a side-effect, _BCL will place a Lenovo Vista
 165 +        * BIOS in ACPI backlight control mode.  We do NOT have to care
 166 +        * about calling the _BCL method in an enabled video device, any
 167 +        * will do for our purposes.
 168 +        */
 169 +
 170         status = acpi_walk_namespace(ACPI_TYPE_METHOD, vid_handle, 3,
 171 -                                    brightness_find_bcl, NULL, &found_node);
 172 +                                    brightness_find_bcl, NULL, &bcl_ptr);
 173 +
 174 +       if (ACPI_SUCCESS(status) && bcl_levels > 2)
 175 +               return (bcl_levels - 2);
 176
 177 -       return (ACPI_SUCCESS(status) && found_node != NULL);
 178 +       return 0;
 179  }
 180
 181  static int __init brightness_init(struct ibm_init_struct *iibm)
 182 @@ -4374,13 +4367,19 @@ static int __init brightness_init(struct ibm_init_struct *iibm)
 183
 184         mutex_init(&brightness_mutex);
 185
 186 -       if (!brightness_enable) {
 187 -               dbg_printk(TPACPI_DBG_INIT,
 188 -                          "brightness support disabled by "
 189 -                          "module parameter\n");
 190 -               return 1;
 191 -       } else if (brightness_enable > 1) {
 192 -               if (brightness_check_std_acpi_support()) {
 193 +       /*
 194 +        * We always attempt to detect acpi support, so as to switch
 195 +        * Lenovo Vista BIOS to ACPI brightness mode even if we are not
 196 +        * going to publish a backlight interface
 197 +        */
 198 +       b = brightness_check_std_acpi_support();
 199 +       if (b > 0) {
 200 +               if (thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO) {
 201 +                       printk(TPACPI_NOTICE
 202 +                              "Lenovo BIOS switched to ACPI backlight "
 203 +                              "control mode\n");
 204 +               }
 205 +               if (brightness_enable > 1) {
 206                         printk(TPACPI_NOTICE
 207                                "standard ACPI backlight interface "
 208                                "available, not loading native one...\n");
 209 @@ -4388,6 +4387,22 @@ static int __init brightness_init(struct ibm_init_struct *iibm)
 210                 }
 211         }
 212
 213 +       if (!brightness_enable) {
 214 +               dbg_printk(TPACPI_DBG_INIT,
 215 +                          "brightness support disabled by "
 216 +                          "module parameter\n");
 217 +               return 1;
 218 +       }
 219 +
 220 +       if (b > 16) {
 221 +               printk(TPACPI_ERR
 222 +                      "Unsupported brightness interface, "
 223 +                      "please contact %s\n", TPACPI_MAIL);
 224 +               return 1;
 225 +       }
 226 +       if (b == 16)
 227 +               tp_features.bright_16levels = 1;
 228 +
 229         if (!brightness_mode) {
 230                 if (thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO)
 231                         brightness_mode = 2;
 232 @@ -4401,10 +4416,6 @@ static int __init brightness_init(struct ibm_init_struct *iibm)
 233         if (brightness_mode > 3)
 234                 return -EINVAL;
 235
 236 -       tp_features.bright_16levels =
 237 -                       thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO &&
 238 -                       brightness_check_levels();
 239 -
 240         b = brightness_get(NULL);
 241         if (b < 0)
 242                 return 1;
 243 --
 244 1.5.4.2
 245