From d2939424ff89f1ee3aeefdd030cba6ba163e77ac Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Thu, 20 Jul 2017 12:25:17 +0300 Subject: [PATCH] Revert "drm/i915: Add heuristic to determine better way to adjust brightness" Git-commit: d2939424ff89f1ee3aeefdd030cba6ba163e77ac Patch-mainline: v4.14-rc1 References: FATE#322643 bsc#1055900 This reverts commit 560a758d39c616f83ac25ff6e0816a49ebe6401c. The DPCD backlight commits regress a Thinkpad X1 Carbon 4th Gen and a BXT-P (in CI). Enabling dynamic backlight boots to a black screen, and enabling DPCD backlight leads to a black screen after suspend/resume. References: http://mid.mail-archive.com/20170706135349.6tu3lz7uehazlnnn@boom References: http://mid.mail-archive.com/20170627132326.f2q3yn4bh5flji4q@boom Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101619 Reported-by: David Weinehall Fixes: 560a758d39c6 ("drm/i915: Add heuristic to determine better way to adjust brightness") Cc: Jenny TC Cc: David Weinehall Cc: Puthikorn Voravootivat Cc: Dhinakaran Pandiyan Cc: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org Reviewed-by: Dhinakaran Pandiyan Acked-by: Daniel Vetter Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/f49a89a05f18e90871c2eeadcdcd783ac7961cdf.1500542254.git.jani.nikula@intel.com Acked-by: Takashi Iwai --- drivers/gpu/drm/i915/i915_params.c | 7 +- drivers/gpu/drm/i915/i915_params.h | 2 drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 61 +------------------------- 3 files changed, 7 insertions(+), 63 deletions(-) --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -63,7 +63,7 @@ struct i915_params i915 __read_mostly = .huc_firmware_path = NULL, .enable_dp_mst = true, .inject_load_failure = 0, - .enable_dpcd_backlight = -1, + .enable_dpcd_backlight = false, .enable_gvt = false, }; @@ -246,10 +246,9 @@ MODULE_PARM_DESC(enable_dp_mst, module_param_named_unsafe(inject_load_failure, i915.inject_load_failure, uint, 0400); MODULE_PARM_DESC(inject_load_failure, "Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)"); -module_param_named_unsafe(enable_dpcd_backlight, i915.enable_dpcd_backlight, int, 0600); +module_param_named(enable_dpcd_backlight, i915.enable_dpcd_backlight, bool, 0600); MODULE_PARM_DESC(enable_dpcd_backlight, - "Enable support for DPCD backlight control " - "(-1:auto (default), 0:force disable, 1:force enabled if supported"); + "Enable support for DPCD backlight control (default:false)"); module_param_named(enable_gvt, i915.enable_gvt, bool, 0400); MODULE_PARM_DESC(enable_gvt, --- a/drivers/gpu/drm/i915/i915_params.h +++ b/drivers/gpu/drm/i915/i915_params.h @@ -53,7 +53,6 @@ func(int, edp_vswing); \ func(int, reset); \ func(unsigned int, inject_load_failure); \ - func(int, enable_dpcd_backlight); \ /* leave bools at the end to not create holes */ \ func(bool, alpha_support); \ func(bool, enable_cmd_parser); \ @@ -67,6 +66,7 @@ func(bool, verbose_state_checks); \ func(bool, nuclear_pageflip); \ func(bool, enable_dp_mst); \ + func(bool, enable_dpcd_backlight); \ func(bool, enable_gvt) #define MEMBER(T, member) T member --- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c @@ -259,66 +259,15 @@ intel_dp_aux_display_control_capable(str /* Check the eDP Display control capabilities registers to determine if * the panel can support backlight control over the aux channel */ - if ((intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP) && - (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) { + if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP && + (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) && + !(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP)) { DRM_DEBUG_KMS("AUX Backlight Control Supported!\n"); return true; } return false; } -/* - * Heuristic function whether we should use AUX for backlight adjustment or not. - * - * We should use AUX for backlight brightness adjustment if panel doesn't this - * via PWM pin or using AUX is better than using PWM pin. - * - * The heuristic to determine that using AUX pin is better than using PWM pin is - * that the panel support any of the feature list here. - * - Regional backlight brightness adjustment - * - Backlight PWM frequency set - * - More than 8 bits resolution of brightness level - * - Backlight enablement via AUX and not by BL_ENABLE pin - * - * If all above are not true, assume that using PWM pin is better. - */ -static bool -intel_dp_aux_display_control_heuristic(struct intel_connector *connector) -{ - struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); - uint8_t reg_val; - - /* Panel doesn't support adjusting backlight brightness via PWN pin */ - if (!(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP)) - return true; - - /* Panel supports regional backlight brightness adjustment */ - if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_GENERAL_CAP_3, - ®_val) != 1) { - DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n", - DP_EDP_GENERAL_CAP_3); - return false; - } - if (reg_val > 0) - return true; - - /* Panel supports backlight PWM frequency set */ - if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP) - return true; - - /* Panel supports more than 8 bits resolution of brightness level */ - if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) - return true; - - /* Panel supports enabling backlight via AUX but not by BL_ENABLE pin */ - if ((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) && - !(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP)) - return true; - - return false; - -} - int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector) { struct intel_panel *panel = &intel_connector->panel; @@ -329,10 +278,6 @@ int intel_dp_aux_init_backlight_funcs(st if (!intel_dp_aux_display_control_capable(intel_connector)) return -ENODEV; - if (i915.enable_dpcd_backlight == -1 && - !intel_dp_aux_display_control_heuristic(intel_connector)) - return -ENODEV; - panel->backlight.setup = intel_dp_aux_setup_backlight; panel->backlight.enable = intel_dp_aux_enable_backlight; panel->backlight.disable = intel_dp_aux_disable_backlight;