From 71ae2ba1facb138086fe004a250fcca426bd2ca4 Mon Sep 17 00:00:00 2001 From: Henrique de Moraes Holschuh Date: Sat, 3 Sep 2011 15:49:29 -0300 Subject: [PATCH] thinkpad-acpi: document backlight level writeback at driver init Document this, it is no fun to try to second guess why this sort of stuff is in place years after it was added... Signed-off-by: Henrique de Moraes Holschuh --- drivers/platform/x86/thinkpad_acpi.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 33be4f46566..25b7b9e85eb 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -6399,6 +6399,11 @@ static int __init brightness_init(struct ibm_init_struct *iibm) ibm_backlight_device->props.max_brightness = bright_maxlvl; ibm_backlight_device->props.brightness = b & TP_EC_BACKLIGHT_LVLMSK; + + /* Added by mistake in early 2007. Probably useless, but it could + * be working around some unknown firmware problem where the value + * read at startup doesn't match the real hardware state... so leave + * it in place just in case */ backlight_update_status(ibm_backlight_device); vdbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_BRGHT, -- 2.11.4.GIT