From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 47FD1FF60EE for ; Tue, 31 Mar 2026 09:06:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BD17B10E9A3; Tue, 31 Mar 2026 09:06:07 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Zxg6PLo/"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2003910E997; Tue, 31 Mar 2026 09:06:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1774947965; x=1806483965; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=qnRRtne5gspPSLbvOe1OG+a9Kb5Rkdq52jazPl5pXjg=; b=Zxg6PLo/aWt0bR7b7RDBoggFyQ9R5kLDpIUnkzbcCmjrYLLLcV2gpiVl bc7weAgQy/ljXxolushG7CEwa59/uH5WrVYeL1rx+bGy0Ql1uShT2eVKC EEKklgBe2ZjTUZenEG77WXYxB/Z+Tq1OVrVTvEc/0ra2l1lfPwj9OsHzq ZbRCF8JAdZV01K7W0zOeOa5XHxvixe3gOVKVQWi4WWqPZprng7VaWWLlw D5LrdwLLNhpArfBmMRwHIfadF31VmGc4LuGciGjOLFSj5SvPAh14k1QS8 0LLUBmuYlS8gbHxdgkRhZD2L/IU9PHO71Q5Glb1wOxPwaPQGr6r7cDdxv A==; X-CSE-ConnectionGUID: cfIyuGaXQUenjDwwiGZsZQ== X-CSE-MsgGUID: lXm2dbZIRFed6qfsDo92ew== X-IronPort-AV: E=McAfee;i="6800,10657,11744"; a="87420605" X-IronPort-AV: E=Sophos;i="6.23,151,1770624000"; d="scan'208";a="87420605" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Mar 2026 02:06:05 -0700 X-CSE-ConnectionGUID: sW6K7L+kTESVB5s9YOKxrw== X-CSE-MsgGUID: PIwdVhwXTaOsmIYnDNU1NA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,151,1770624000"; d="scan'208";a="226559627" Received: from srr4-3-linux-106-armuthy.iind.intel.com ([10.190.238.56]) by orviesa007.jf.intel.com with ESMTP; 31 Mar 2026 02:06:00 -0700 From: Arun R Murthy Date: Tue, 31 Mar 2026 14:33:53 +0530 Subject: [PATCH v11 1/7] drm: Define user readable error codes for atomic ioctl MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260331-atomic-v11-1-6a1df7ec5af8@intel.com> References: <20260331-atomic-v11-0-6a1df7ec5af8@intel.com> In-Reply-To: <20260331-atomic-v11-0-6a1df7ec5af8@intel.com> To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jani Nikula , Rodrigo Vivi , Joonas Lahtinen , Tvrtko Ursulin , xaver.hugl@kde.org, harry.wentland@amd.com, uma.shankar@intel.com, louis.chauvet@bootlin.com, naveen1.kumar@intel.com, ramya.krishna.yella@intel.com Cc: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, Arun R Murthy , Suraj Kandpal X-Mailer: b4 0.15-dev X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" There can be multiple reasons for a failure in atomic_ioctl. Most often in these error conditions -EINVAL is returned. User/Compositor would have to blindly take a call on failure of this ioctl so as to use ALLOW_MODESET or retry. It would be good if user/compositor gets a readable error code on failure so they can take proper corrections in the next commit. The struct drm_mode_atomic is being passed by the user/compositor which holds the properties for modeset/flip. Reusing the same struct for returning the error code in case of failure, thereby creation of new uapi/interface for returning the error code is not required. The element 'reserved' in the struct drm_mode_atomic is used for returning the user readable error code. This points to the struct drm_mode_atomic_err_code. Failure reasons as a string can also be added on need basis by the variable failure_string in the same struct drm_mode_atomic_err_code. v3: Remove fixed error (Jani/Xaver) v5: Fix kernel-doc (Jani) v7: Rephrase the kernel doc description (Suraj) v8: Removed the below enum and suggest to use INVALID_API_USAGE (Xaver) DRM_MODE_ATOMIC_ASYNC_NOT_SUPP_PLANE DRM_MODE_ATOMIC_ASYNC_MODIFIER_NOT_SUPP v10: Added more error codes for the enum v11: Add default/unspecified error code Signed-off-by: Arun R Murthy Reviewed-by: Suraj Kandpal --- include/uapi/drm/drm_mode.h | 56 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index a4bdc4bd11bc142e9d3b172397e18a1909a21488..8bf5fd8533912dc7a188aad19cc3741dd2099592 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -48,6 +48,7 @@ extern "C" { #define DRM_CONNECTOR_NAME_LEN 32 #define DRM_DISPLAY_MODE_LEN 32 #define DRM_PROP_NAME_LEN 32 +#define DRM_MODE_ATOMIC_FAILURE_STRING_LEN 128 #define DRM_MODE_TYPE_BUILTIN (1<<0) /* deprecated */ #define DRM_MODE_TYPE_CLOCK_C ((1<<1) | DRM_MODE_TYPE_BUILTIN) /* deprecated */ @@ -1346,6 +1347,61 @@ struct drm_mode_destroy_dumb { DRM_MODE_ATOMIC_NONBLOCK |\ DRM_MODE_ATOMIC_ALLOW_MODESET) +/** + * enum drm_mode_atomic_failure_codes - error codes for failures in atomic_ioctl + * @DRM_MODE_ATOMIC_UNSPECIFIED_ERROR: this is the default/unspecified error. + * @DRM_MODE_ATOMIC_INVALID_API_USAGE: invallid API usage(DRM_ATOMIC not + * enabled, invalid falg, page_flip event + * with test-only, etc) + * @DRM_MODE_ATOMIC_NEED_FULL_MODESET: Need full modeset on all connected crtc's + * @DRM_MODE_ATOMIC_ASYNC_PROP_CHANGED: Property changed in async flip + * @DRM_MODE_ATOMIC_SCANOUT_BW: For a given resolution, refresh rate and the + * color depth cannot be accomodated. Resolution + * is to lower the refresh rate or color depth. + * @DRM_MODE_ATOMIC_CONNECTOR_BW: Refers to the limitation on the link rate on + * a given connector. + * @DRM_MODE_ATOMIC_PIPE_BW: Limitation on the pipe, either pipe not available + * or the pipe scaling factor limitation. + * @DRM_MODE_ATOMIC_MEMORY_DOMAIN: Any other memory/bandwidth related limitation + * other then the ones specified above. + * @DRM_MODE_ATOMIC_SPEC_VIOLOATION: Limitation of a particular feature on that + * hardware. To get to know the feature, the + * property/object causing this is being sent + * back to user @failure_objs_ptr in the + * struct drm_mode_atomic_err_code + */ +enum drm_mode_atomic_failure_codes { + DRM_MODE_ATOMIC_UNSPECIFIED_ERROR, + DRM_MODE_ATOMIC_INVALID_API_USAGE, + DRM_MODE_ATOMIC_NEED_FULL_MODESET, + DRM_MODE_ATOMIC_ASYNC_PROP_CHANGED, + DRM_MODE_ATOMIC_SCANOUT_BW, + DRM_MODE_ATTOMIC_CONNECTOR_BW, + DRM_MODE_ATTOMIC_PIPE_BW, + DRM_MODE_ATOMIC_MEMORY_DOMAIN, + DRM_MODE_ATOMIC_SPEC_VIOLOATION, +}; + +/** + * struct drm_mode_atomic_err_code - struct to store the error code + * + * pointer to this struct will be stored in reserved variable of + * struct drm_mode_atomic to report the failure cause to the user. + * + * @failure_code: error codes defined in enum drm_moide_atomic_failure_code + * @failure_objs_ptr: pointer to the drm_object that caused error + * @reserved: reserved for future use + * @count_objs: count of drm_objects if multiple drm_objects caused error + * @failure_string: user readable error message string + */ +struct drm_mode_atomic_err_code { + __u64 failure_code; + __u64 failure_objs_ptr; + __u64 reserved; + __u32 count_objs; + char failure_string[DRM_MODE_ATOMIC_FAILURE_STRING_LEN]; +}; + struct drm_mode_atomic { __u32 flags; __u32 count_objs; -- 2.25.1