From d64c81c4cea0a14e88fc76e2c845e4885e491754 Mon Sep 17 00:00:00 2001 From: Henrique de Moraes Holschuh Date: Sat, 18 Oct 2008 14:23:55 -0300 Subject: [PATCH] ACPI: thinkpad-acpi: Remove firmware backlight delays for Intel ACPI IGD OpRegion Based on analysis and a patch from Matthew Garrett . Instruct the ThinkPad ACPI firmware to remove delays on the processing of backlight brightness changes. This method is present on ThinkPad Vista-compatible BIOSes with standard ACPI backlight level control. Signed-off-by: Henrique de Moraes Holschuh Cc: Matthew Garrett Cc: Yves-Alexis Perez Signed-off-by: Len Brown --- drivers/misc/thinkpad_acpi.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c index 4c47f9b80478..17b8281deee5 100644 --- a/drivers/misc/thinkpad_acpi.c +++ b/drivers/misc/thinkpad_acpi.c @@ -838,6 +838,13 @@ static int parse_strtoul(const char *buf, return 0; } +static void tpacpi_disable_brightness_delay(void) +{ + if (acpi_evalf(hkey_handle, NULL, "PWMS", "qvd", 0)) + printk(TPACPI_NOTICE + "ACPI backlight control delay disabled\n"); +} + static int __init tpacpi_query_bcl_levels(acpi_handle handle) { struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; @@ -2139,6 +2146,8 @@ static int __init hotkey_init(struct ibm_init_struct *iibm) if (!tp_features.hotkey) return 1; + tpacpi_disable_brightness_delay(); + hotkey_dev_attributes = create_attr_set(13, NULL); if (!hotkey_dev_attributes) return -ENOMEM; @@ -2512,6 +2521,8 @@ static void hotkey_suspend(pm_message_t state) static void hotkey_resume(void) { + tpacpi_disable_brightness_delay(); + if (hotkey_mask_get()) printk(TPACPI_ERR "error while trying to read hot key mask " -- 2.20.1