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 CDEE8EA3F2E for ; Tue, 10 Feb 2026 09:05:38 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 344B410E501; Tue, 10 Feb 2026 09:05:38 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="f5NAc4wM"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7665E10E4FE; Tue, 10 Feb 2026 09:05:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1770714337; x=1802250337; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=G4BMkhSaHKQ0kvRPZs6Gsy8zI84WYy2KBWtLkFjtTQc=; b=f5NAc4wMdoOC0iRig16x0x/MUV9o/bkukPy+/QW2bz+MpDewuiiFoKV4 PL7IEL6FsvGZPS2RDeiCRNcudtrYyojRbVvssf/OqG8Ko3/hfj0K4YpFF quZAIkBb/wU8drioFC4RqCaVzx2wWOKEM8V1VJl8CeH3NiBEqVnp0SAKO 6420m8zWLw3ygdOb1DhNPHvarN2YqjhPAaGg8YrRvUEv45n3xLpRNXBiL YhNPWeTROpEiln//YImOZXm1zxgiCrQuonYpMr6GfMhdNNxPJSNr4gt9t zRuWUtFG18eT+NYnzAifwDpoP421jf13Ia6n8q62oifkGkgknw05pIwSw w==; X-CSE-ConnectionGUID: MmaTHNKQTJ2Jqwr3wZYoow== X-CSE-MsgGUID: jiK0JFThSk+mG76M49ZdpA== X-IronPort-AV: E=McAfee;i="6800,10657,11696"; a="94479152" X-IronPort-AV: E=Sophos;i="6.21,283,1763452800"; d="scan'208";a="94479152" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2026 01:05:36 -0800 X-CSE-ConnectionGUID: uBzUFk7LRcyRRacCHwO+tg== X-CSE-MsgGUID: EbjNfNGcR8SOnvrvAaS2sA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,283,1763452800"; d="scan'208";a="242478926" Received: from srr4-3-linux-106-armuthy.iind.intel.com ([10.190.238.56]) by orviesa002.jf.intel.com with ESMTP; 10 Feb 2026 01:05:31 -0800 From: Arun R Murthy Date: Tue, 10 Feb 2026 14:33:55 +0530 Subject: [PATCH v9 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: <20260210-atomic-v9-1-525c88fd2402@intel.com> References: <20260210-atomic-v9-0-525c88fd2402@intel.com> In-Reply-To: <20260210-atomic-v9-0-525c88fd2402@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: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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 Signed-off-by: Arun R Murthy Reviewed-by: Suraj Kandpal --- include/uapi/drm/drm_mode.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index 3693d82b5279f1cf14fc2adb538ea830591cc598..71e91d4f05ee8d556e8e7137a6cdcc7f3b261a75 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 */ @@ -1343,6 +1344,42 @@ 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_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_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_PROP_CHANGED, +}; + +/** + * 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