From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793638173; b=r9CYIshxjZUDe5e2c/C8qFcUC32ctpJmgZR6L/TcyNVlsbOmdxOglpkZ/f7CCPfRTRKT nXKXrRzvRvqfHeRkAEu1jL+VItD4qPuLVMPN/LrWT9PvRE1zumXoIf9nyrD3i0jh7BYAe JZmuL0znBykAOUGeBkimkrUm45blbJq+CjpcA6jVlHE2SKgRCXMggoqovh+iHaFy8iGSi AqJiojckdrkuVaDMP1D+8ueiKGgfdO9OMmkaL/OGEInxAJJsLeaBvURjn4Hpnw0Vq7z0D wKo6s+Tgo2j0w16u+7fsDQcQZIoEWXniWZToc1XIlKljYLBcrPmGKAB6/+oVsZGxVBA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793638173; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:References:In-Reply-To:To:Cc: X-Mailer; bh=cvbBm4Tp3/ViJKgby3dRF7WjDg9OW1cC4hM7fJo8a3M=; b=LWQE1zbYCJs/moyNvYFXQuoIp8wFNT01sId6qAvGyfSSC+BpmHqzFWV10DsyS9BEOb1n BBECz69A+mnGTQkbbGUmw/UkmT666Mblzfw4tzqXvq2aU1D9E/P2QpRnChMtdvcmkCYRM pBt1YQRmIG4ZRJwBhQL0AwfCOgwJwhgkZ135SdZXyknx+Bs4l2tBD5bmOEZl4VXVKnR0E hcDYSo073RCq6OtWuZUyF7/RfGfEo4lO3tMgQzFm12YxDPaqKCyL54p6New56/qRHpXkw Y6+UVY7jQFgxU6E+j/+ZtumBbaXMxjZbIyHuV7qy6vEmWtbggrjaRMFwFMsKQcXxYIQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=WhOtx3Fm; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6B2A0606D80D for ; Mon, 2 Nov 2026 16:49:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=WhOtx3Fm Received: by smtp.kernel.org (Postfix) with ESMTPSA id 604F71F00A1A; Mon, 2 Nov 2026 16:49:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793638173; bh=cvbBm4Tp3/ViJKgby3dRF7WjDg9OW1cC4hM7fJo8a3M=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=WhOtx3Fm6Hv32lNSjNjq810YCZ3Pa4vOYTu30yq1tvSCDlN4J7gqTXEMjGbMbFUxz HE9BEt5A+QDNKrUMcgyqDKdRXjBetosn6IgcIwrj9yjvkshs7wS0grdP8eRjB4LtbI DU6is3Jd87W4dI8F/MeDlZKZE8LAPJiHvcEh6d20sf0ogzNsAHk8vGNkB2qDDKGDyx GhqUBenu5GT/YsEdkI3gysDLEFDeyafwgMmLnHCu9xoIeue1yWwS55RgScIuSbL8SH KpRWsZRa3l9b6QHmh8q9H9ajIl2UI35Wfo2VtA4Sp+d2kHj0pJ7lk5CGSE6t06mHPm sdAACQ6j/hn9Q== From: "Mario Limonciello (AMD)" Date: Mon, 02 Nov 2026 10:49:18 -0600 Subject: [PATCH v10 02/15] drm/amd/display: Pass up errors reading actual brightness X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261102-superm1-backlight-property-v10-2-b2a6f24131f5@kernel.org> References: <20261102-superm1-backlight-property-v10-0-b2a6f24131f5@kernel.org> In-Reply-To: <20261102-superm1-backlight-property-v10-0-b2a6f24131f5@kernel.org> To: Maxime Ripard , Alex Deucher , Jani Nikula , Javier Martinez Canillas , Maarten Lankhorst , Thomas Zimmermann , David Airlie , Simona Vetter , Harry Wentland , Leo Li , Rodrigo Siqueira Cc: Mario Limonciello , Xaver Hugl , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, nouveau@lists.freedesktop.org, Mario Limonciello X-Mailer: b4 0.16.0 From: Mario Limonciello [Why] If the DC API fails to return actual brightness when backlight control API requests it, then the wrong value may be returned. [How] Change return type of amdgpu_dm_backlight_get_level() to an integer and pass an error code up to the caller. Signed-off-by: Mario Limonciello --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c | 13 +++++++++---- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h | 2 +- .../amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c | 4 ++-- 3 files changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c index cb74b00723fda..0f664c658a127 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c @@ -438,7 +438,7 @@ int amdgpu_dm_backlight_update_status(struct backlight_device *bd) EXPORT_IF_KUNIT(amdgpu_dm_backlight_update_status); STATIC_IFN_KUNIT -u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx) +int amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx) { int ret; struct amdgpu_dm_backlight_caps caps; @@ -451,14 +451,14 @@ u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx) u32 avg, peak; if (!dc_link_get_backlight_level_nits(link, &avg, &peak)) - return dm->brightness[bl_idx]; + return -EINVAL; return convert_brightness_to_user(&caps, avg); } ret = dc_link_get_backlight_level(link); if (ret == DC_ERROR_UNEXPECTED) - return dm->brightness[bl_idx]; + return -EINVAL; return convert_brightness_to_user(&caps, ret); } @@ -469,8 +469,13 @@ int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd) { struct amdgpu_display_manager *dm = bl_get_data(bd); int i = amdgpu_dm_backlight_get_device_index(dm, bd); + int ret; + + ret = amdgpu_dm_backlight_get_level(dm, i); + if (ret < 0) + return dm->brightness[i]; - return amdgpu_dm_backlight_get_level(dm, i); + return ret; } EXPORT_IF_KUNIT(amdgpu_dm_backlight_get_brightness); diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h index 9ad888d3ae7b2..891749322191c 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.h @@ -57,7 +57,7 @@ void amdgpu_dm_validate_backlight_caps(struct amdgpu_display_manager *dm, int bl struct dc_stream_state *dm_find_stream_with_link(struct amdgpu_display_manager *dm, struct dc_link *link); int amdgpu_dm_backlight_update_status(struct backlight_device *bd); -u32 amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx); +int amdgpu_dm_backlight_get_level(struct amdgpu_display_manager *dm, int bl_idx); int amdgpu_dm_backlight_get_brightness(struct backlight_device *bd); ssize_t panel_power_savings_show(struct device *device, struct device_attribute *attr, diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c index 5221050dec2f1..b21850788f36f 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/amdgpu_dm_backlight_test.c @@ -382,7 +382,7 @@ static void dm_test_backlight_get_level_pwm_error(struct kunit *test) dm->brightness[0] = 4321; dm->backlight_link[0] = link; - KUNIT_EXPECT_EQ(test, amdgpu_dm_backlight_get_level(dm, 0), 4321U); + KUNIT_EXPECT_EQ(test, amdgpu_dm_backlight_get_level(dm, 0), -EINVAL); } /** @@ -424,7 +424,7 @@ static void dm_test_backlight_get_level_aux_error(struct kunit *test) caps->caps_valid = true; caps->aux_support = true; - KUNIT_EXPECT_EQ(test, amdgpu_dm_backlight_get_level(dm, 0), 6789U); + KUNIT_EXPECT_EQ(test, amdgpu_dm_backlight_get_level(dm, 0), -EINVAL); } /** -- 2.53.0