From 1326d472787ccad807f9d2538ed4871c92f05faf Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Fri, 22 Nov 2019 18:16:02 -0500 Subject: [PATCH 5/7] drm/i915: Auto detect DPCD backlight support by default Turns out we actually already have some companies, such as Lenovo, shipping machines with AMOLED screens that don't allow controlling the backlight through the usual PWM interface and only allow controlling it through the standard EDP DPCD interface. One example of one of these laptops is the X1 Extreme 2nd Generation. Since we've got systems that need this turned on by default now to have backlight controls working out of the box, let's start auto-detecting it for systems by default based on what the VBT tells us. We do this by changing the default value for the enable_dpcd_backlight module param from 0 to -1. Signed-off-by: Lyude Paul Reviewed-by: Jani Nikula --- drivers/gpu/drm/i915/i915_params.c | 2 +- drivers/gpu/drm/i915/i915_params.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 36c12a229a1a..ce31efc28674 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -166,7 +166,7 @@ i915_param_named_unsafe(inject_load_failure, uint, 0400, i915_param_named(enable_dpcd_backlight, int, 0600, "Enable support for DPCD backlight control" - "(-1=use per-VBT LFP backlight type setting, 0=disabled [default], 1=enabled)"); + "(-1=use per-VBT LFP backlight type setting [default], 0=disabled, 1=enabled)"); #if IS_ENABLED(CONFIG_DRM_I915_GVT) i915_param_named(enable_gvt, bool, 0400, diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h index 1baeac0f47ab..37aa5115a92c 100644 --- a/drivers/gpu/drm/i915/i915_params.h +++ b/drivers/gpu/drm/i915/i915_params.h @@ -54,7 +54,7 @@ struct drm_printer; param(int, edp_vswing, 0) \ param(int, reset, 2) \ param(unsigned int, inject_load_failure, 0) \ - param(int, enable_dpcd_backlight, 0) \ + param(int, enable_dpcd_backlight, -1) \ /* leave bools at the end to not create holes */ \ param(bool, alpha_support, IS_ENABLED(CONFIG_DRM_I915_ALPHA_SUPPORT)) \ param(bool, enable_hangcheck, true) \ -- 2.17.1