From: Jani Nikula Date: Thu, 19 Nov 2015 08:26:30 +0000 (+0200) Subject: Revert "drm/i915: skip modeset if compatible for everyone." X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7383123647566a813692bb37a1389c767ed89158;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git Revert "drm/i915: skip modeset if compatible for everyone." This reverts commit 6764e9f8724f1231b4deac53b9a82286ac0830e7 Author: Maarten Lankhorst Date: Thu Aug 27 15:44:06 2015 +0200 drm/i915: skip modeset if compatible for everyone. Bring back the i915.fastboot module parameter, disabled by default, due to backlight regression on Chromebook Pixel 2015. Apparently the firmware of the Chromebook in question enables the panel but disables backlight to avoid a brief garbage scanout upon loading the kernel/module. With fastboot, we leave the backlight untouched, in this case disabled. The user would have to do a modeset (i.e. not just crank up the brightness) to enable the backlight. There is no clean fix readily available, so get back to the drawing board by reverting. [N.B. The reference below is for when the thread was included on public lists, and some of the context had already been dropped by then.] Reported-and-tested-by: Olof Johansson Acked-by: Maarten Lankhorst Acked-by: Daniel Vetter References: http://marc.info/?i=CAKMK7uES7xk05ki92oeX6gmvZWAh9f2vL7yz=6T+fGK9J3X7cQ@mail.gmail.com Fixes: 6764e9f8724f ("drm/i915: skip modeset if compatible for everyone.") Signed-off-by: Jani Nikula Link: http://patchwork.freedesktop.org/patch/msgid/1447921590-3785-1-git-send-email-jani.nikula@intel.com --- diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 84b5db257f1b..95bb27de774f 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2651,6 +2651,7 @@ struct i915_params { int enable_cmd_parser; /* leave bools at the end to not create holes */ bool enable_hangcheck; + bool fastboot; bool prefault_disable; bool load_detect_test; bool reset; diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 96bb23865eac..4be13a5eb932 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -40,6 +40,7 @@ struct i915_params i915 __read_mostly = { .preliminary_hw_support = IS_ENABLED(CONFIG_DRM_I915_PRELIMINARY_HW_SUPPORT), .disable_power_well = -1, .enable_ips = 1, + .fastboot = 0, .prefault_disable = 0, .load_detect_test = 0, .reset = true, @@ -133,6 +134,10 @@ MODULE_PARM_DESC(disable_power_well, module_param_named_unsafe(enable_ips, i915.enable_ips, int, 0600); MODULE_PARM_DESC(enable_ips, "Enable IPS (default: true)"); +module_param_named(fastboot, i915.fastboot, bool, 0600); +MODULE_PARM_DESC(fastboot, + "Try to skip unnecessary mode sets at boot time (default: false)"); + module_param_named_unsafe(prefault_disable, i915.prefault_disable, bool, 0600); MODULE_PARM_DESC(prefault_disable, "Disable page prefaulting for pread/pwrite/reloc (default:false). " diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 002e2a41ce1b..71860f8680f9 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -13068,7 +13068,8 @@ static int intel_atomic_check(struct drm_device *dev, if (ret) return ret; - if (intel_pipe_config_compare(state->dev, + if (i915.fastboot && + intel_pipe_config_compare(state->dev, to_intel_crtc_state(crtc->state), pipe_config, true)) { crtc_state->mode_changed = false;