releases/upstream/2.6.28-rc1/0005-ACPI-thinkpad-acpi-Remove-firmware-backlight-delay.patch

   1 From d64c81c4cea0a14e88fc76e2c845e4885e491754 Mon Sep 17 00:00:00 2001
   2 From: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
   3 Date: Sat, 18 Oct 2008 14:23:55 -0300
   4 Subject: ACPI: thinkpad-acpi: Remove firmware backlight delays for Intel ACPI IGD OpRegion
   5
   6 Based on analysis and a patch from Matthew Garrett <mjg59@srcf.ucam.org>.
   7
   8 Instruct the ThinkPad ACPI firmware to remove delays on the processing of
   9 backlight brightness changes.  This method is present on ThinkPad
  10 Vista-compatible BIOSes with standard ACPI backlight level control.
  11
  12 Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
  13 Cc: Matthew Garrett <mjg59@srcf.ucam.org>
  14 Cc: Yves-Alexis Perez <corsac@debian.org>
  15 Signed-off-by: Len Brown <len.brown@intel.com>
  16 ---
  17  drivers/misc/thinkpad_acpi.c |   11 +++++++++++
  18  1 files changed, 11 insertions(+), 0 deletions(-)
  19
  20 diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
  21 index 4c47f9b..17b8281 100644
  22 --- a/drivers/misc/thinkpad_acpi.c
  23 +++ b/drivers/misc/thinkpad_acpi.c
  24 @@ -838,6 +838,13 @@ static int parse_strtoul(const char *buf,
  25         return 0;
  26  }
  27
  28 +static void tpacpi_disable_brightness_delay(void)
  29 +{
  30 +       if (acpi_evalf(hkey_handle, NULL, "PWMS", "qvd", 0))
  31 +               printk(TPACPI_NOTICE
  32 +                       "ACPI backlight control delay disabled\n");
  33 +}
  34 +
  35  static int __init tpacpi_query_bcl_levels(acpi_handle handle)
  36  {
  37         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  38 @@ -2139,6 +2146,8 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
  39         if (!tp_features.hotkey)
  40                 return 1;
  41
  42 +       tpacpi_disable_brightness_delay();
  43 +
  44         hotkey_dev_attributes = create_attr_set(13, NULL);
  45         if (!hotkey_dev_attributes)
  46                 return -ENOMEM;
  47 @@ -2512,6 +2521,8 @@ static void hotkey_suspend(pm_message_t state)
  48
  49  static void hotkey_resume(void)
  50  {
  51 +       tpacpi_disable_brightness_delay();
  52 +
  53         if (hotkey_mask_get())
  54                 printk(TPACPI_ERR
  55                        "error while trying to read hot key mask "
  56 --
  57 1.5.6.5
  58