From 2fb364bbd4aaa613131449e6f7a68a341c0ac5ab Mon Sep 17 00:00:00 2001 From: jsg Date: Mon, 7 Oct 2024 05:30:12 +0000 Subject: [PATCH] drm/amd/display: Validate backlight caps are sane From Mario Limonciello c886061bbdd1f37190939b11926055413e86a56c in linux-6.6.y/6.6.54 327e62f47eb57ae5ff63de82b0815557104e439a in mainline linux --- .../pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 9688dc53952..a74f6e9489e 100644 --- a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4041,6 +4041,7 @@ static int amdgpu_dm_mode_config_init(struct amdgpu_device *adev) #define AMDGPU_DM_DEFAULT_MIN_BACKLIGHT 12 #define AMDGPU_DM_DEFAULT_MAX_BACKLIGHT 255 +#define AMDGPU_DM_MIN_SPREAD ((AMDGPU_DM_DEFAULT_MAX_BACKLIGHT - AMDGPU_DM_DEFAULT_MIN_BACKLIGHT) / 2) #define AUX_BL_DEFAULT_TRANSITION_TIME_MS 50 static void amdgpu_dm_update_backlight_caps(struct amdgpu_display_manager *dm, @@ -4055,6 +4056,21 @@ static void amdgpu_dm_update_backlight_caps(struct amdgpu_display_manager *dm, return; amdgpu_acpi_get_backlight_caps(&caps); + + /* validate the firmware value is sane */ + if (caps.caps_valid) { + int spread = caps.max_input_signal - caps.min_input_signal; + + if (caps.max_input_signal > AMDGPU_DM_DEFAULT_MAX_BACKLIGHT || + caps.min_input_signal < AMDGPU_DM_DEFAULT_MIN_BACKLIGHT || + spread > AMDGPU_DM_DEFAULT_MAX_BACKLIGHT || + spread < AMDGPU_DM_MIN_SPREAD) { + DRM_DEBUG_KMS("DM: Invalid backlight caps: min=%d, max=%d\n", + caps.min_input_signal, caps.max_input_signal); + caps.caps_valid = false; + } + } + if (caps.caps_valid) { dm->backlight_caps[bl_idx].caps_valid = true; if (caps.aux_support) -- 2.20.1