From b7bc596ebbe0cddc97d76ef9309f64471bbf13eb Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Wed, 19 Nov 2014 13:12:54 -0500 Subject: [PATCH] drm/radeon: disable native backlight control on pre-r6xx asics (v2) Just use the acpi interface. That's what windows uses on this generation and it's the only thing that seems to work reliably on these generation parts. You can still force the native backlight interface by setting radeon.backlight=1 Bug: https://bugzilla.kernel.org/show_bug.cgi?id=88501 v2: merge into above if/else block Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org --- drivers/gpu/drm/radeon/radeon_encoders.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/radeon/radeon_encoders.c b/drivers/gpu/drm/radeon/radeon_encoders.c index 9a19e52..6b670b0 100644 --- a/drivers/gpu/drm/radeon/radeon_encoders.c +++ b/drivers/gpu/drm/radeon/radeon_encoders.c @@ -179,6 +179,9 @@ static void radeon_encoder_add_backlight(struct radeon_encoder *radeon_encoder, (rdev->pdev->subsystem_vendor == 0x1734) && (rdev->pdev->subsystem_device == 0x1107)) use_bl = false; + /* disable native backlight control on older asics */ + else if (rdev->family < CHIP_R600) + use_bl = false; else use_bl = true; } -- 2.7.4