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 493C7CD0417 for ; Tue, 6 Jan 2026 04:39:58 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0368D10E46B; Tue, 6 Jan 2026 04:39:58 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="PCxsRr+2"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6FD2910E46B; Tue, 6 Jan 2026 04:39:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1767674398; x=1799210398; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=vKY0nSIZVk5vJgsHVciBfT4QVuDemQ1v/8L7VgDUfY4=; b=PCxsRr+2co3uZebufhGh4U/c6hwK1xSvoAe4ZPDRNlVzn3hcRr1looEs YoqVM2bXX+TdVrPYmB0pylg2yqaIJMxQK6x1Oss4Lyyjisur9Dai2QaZn sDcBtGV5J4jabruexZEBDW61ZkRzGWnkqHROxBzAzgv3dn1oqBEBxu8Ru hQ2pMe5j1Q0kjjqul7MbWlF4RV+Uv0uTVKufutM67EfUfMP1DyWXJJCS2 UUUnt9EwOJT9aBkpI+KbL3DAWHK1720NB+2cpznmnMzflSmn1JLtKwCJY tGCUcAkBW6B4lOFfYfENEBDX4FopaXOmFlH9mtYCQ4UQJknlK6gICh/vE w==; X-CSE-ConnectionGUID: 7eS9neWMQBKAdpNeLO0X9w== X-CSE-MsgGUID: gRUT1KzsR4KlABi4iKc1+Q== X-IronPort-AV: E=McAfee;i="6800,10657,11662"; a="86459288" X-IronPort-AV: E=Sophos;i="6.21,204,1763452800"; d="scan'208";a="86459288" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2026 20:39:57 -0800 X-CSE-ConnectionGUID: V7oAE0u3QgadQ4qR50JAEg== X-CSE-MsgGUID: DwOLZm+oQBWmc/E0S8cKlA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,204,1763452800"; d="scan'208";a="207034324" Received: from srr4-3-linux-106-armuthy.iind.intel.com ([10.190.238.56]) by fmviesa005.fm.intel.com with ESMTP; 05 Jan 2026 20:39:52 -0800 From: Arun R Murthy Date: Tue, 06 Jan 2026 10:07:56 +0530 Subject: [PATCH v7 1/5] 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: <20260106-atomic-v7-1-d51d9a351684@intel.com> References: <20260106-atomic-v7-0-d51d9a351684@intel.com> In-Reply-To: <20260106-atomic-v7-0-d51d9a351684@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 Cc: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, Arun R Murthy X-Mailer: b4 0.15-dev X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" 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. Signed-off-by: Arun R Murthy --- include/uapi/drm/drm_mode.h | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index cbbbfc1dfe2b806c641c720b0215e825e350bd03..024c39eba6b25e14a99b14224d96b7254ccebd61 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -45,6 +45,7 @@ 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 */ @@ -1339,6 +1340,46 @@ struct drm_mode_destroy_dumb { DRM_MODE_ATOMIC_NONBLOCK |\ DRM_MODE_ATOMIC_ALLOW_MODESET) +/** + * enum drm_mode_atomic_err_code - error codes for failures in atomic_ioctl + * @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_CRTC_NEED_FULL_MODESET: Need full modeset on this crtc + * @DRM_MODE_ATOMIC_NEED_FULL_MODESET: Need full modeset on all connected crtc's + * @DRM_MODE_ATOMIC_ASYNC_NOT_SUPP_PLANE: Aync flip not supported on this plane + * DRM_MODE_ATOMIC_ASYNC_MODIFIER_NOT_SUPP: Modifier not supported by async flip + * @DRM_MODE_ATOMIC_ASYNC_PROP_CHANGED: Property changed in async flip + */ +enum drm_mode_atomic_failure_codes { + DRM_MODE_ATOMIC_INVALID_API_USAGE, + DRM_MODE_ATOMIC_CRTC_NEED_FULL_MODESET, + DRM_MODE_ATOMIC_NEED_FULL_MODESET, + DRM_MODE_ATOMIC_ASYNC_NOT_SUPP_PLANE, + DRM_MODE_ATOMIC_ASYNC_MODIFIER_NOT_SUPP, + DRM_MODE_ATOMIC_ASYNC_PROP_CHANGED, +}; + +/** + * 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_string_ptr: pointer to user readable error message string + * @failure_obj_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 + */ +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