From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 05D16379EE6 for ; Thu, 23 Apr 2026 10:07:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776938848; cv=none; b=nUa+4FkIZC6zOdvB42s5tX6rRLo3kNvheDMT+y8oY89sf93qMF0zmAagxexpHMHrTANRO9mFdeNEfJU4b1Nt/rNR/WL+D4vehttl2c8cj3wupxETpjvIZt46gAQHmQVUP0lyPu+mk4zBHN9cG84A9lpzPUsRiOvIo7C3QfsebdQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776938848; c=relaxed/simple; bh=8+FNfWxwQ20fsMj5oozQYABCMKlCSVOCkN7bV3C8s+Y=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=gxva2X1zWN6cFeGkvBxSxdUUKWfL0A3x+yQcZs2bLWBC7WMSgbGAm1lZ9VxQq8kzD000fL6xIXPlIXhJmo0yaQTE3l/q4rYviwjjAqtFgckLNTrpDCUW0Rt24/NVdhDMzqWuwIFqxPzGS6N/LMunbZbbVy9vVtUoXTKjbgs24S4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M0oxVR7c; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="M0oxVR7c" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4310BC2BCB2; Thu, 23 Apr 2026 10:07:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776938847; bh=8+FNfWxwQ20fsMj5oozQYABCMKlCSVOCkN7bV3C8s+Y=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=M0oxVR7c1MdKB4Xcjsm9fV21NYkn0g1Xn3LUotxaRIPDU1bJJkn0Glaz0i1Ogpykh R++AHwfstyQ5S4fAY6KvjkoYTX6V1Z9yGvU9d0hHMkdJInprcaFhspKi6TFJXKsDSl ez5bcBwXhA4z5A6O7CC28A8DWUhp5ZSdNY0qPz87BmHHcnC55O+QTAcfzr5wcdiIxD bTYODRuakS108nOmIzIl5tmbHBe7bUynGv27o7n7HJR1z2xUDP1xVR+d7NmGbu8OJI X62NWKBK/jHPKE40SNvZeE/paHbdUlM2CvRjvvsbx1dAx5N3wxwIqMmwhc+h7iPBho zF7hLO55GROIw== From: Maxime Ripard Date: Thu, 23 Apr 2026 12:06:41 +0200 Subject: [PATCH v2 03/28] drm/atomic_state_helper: Remove memset in __drm_atomic_helper_bridge_reset() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260423-drm-state-readout-v2-3-6cde1a9910ed@kernel.org> References: <20260423-drm-state-readout-v2-0-6cde1a9910ed@kernel.org> In-Reply-To: <20260423-drm-state-readout-v2-0-6cde1a9910ed@kernel.org> To: Maarten Lankhorst , Thomas Zimmermann , David Airlie , Simona Vetter , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Jyri Sarha , Tomi Valkeinen Cc: Devarsh Thakkar , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Maxime Ripard X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1659; i=mripard@kernel.org; h=from:subject:message-id; bh=8+FNfWxwQ20fsMj5oozQYABCMKlCSVOCkN7bV3C8s+Y=; b=owGbwMvMwCmsHn9OcpHtvjLG02pJDJkv37vLynV47L7Dozkh7+JUBqVbzUtKEo7Kih7fsK4j6 e6/uC39HVNZGIQ5GWTFFFmeyISdXt6+uMrBfuUPmDmsTCBDGLg4BWAieZmM9WWsF++tZdx9fpvt vvStiyfdZ1/73X2ZZeq+x3YFYlfzkp0vHbxx+vHUY0vvyHzolz7OKcnY0PZzbY0+D2PuJ85SpzX v5r17/3B7yrdGg6kb3BpXxbz7Kv9s8qnkA/FXHwrdbrk6m+uoDQA= X-Developer-Key: i=mripard@kernel.org; a=openpgp; fpr=BE5675C37E818C8B5764241C254BCFC56BF6CE8D The general consensus is that reset helpers shouldn't call memset directly because the object it initializes is supposed to have been zeroed out. Remove the memset call from __drm_atomic_helper_bridge_reset() and document the expectation. It should not have any impact on the current code base since there's only two callers: drm_atomic_helper_bridge_reset() and cdns-mhdp8546-core's cdns_mhdp_bridge_atomic_reset(), both allocating the object using kzalloc_obj(). Suggested-by: Thomas Zimmermann Signed-off-by: Maxime Ripard --- drivers/gpu/drm/drm_atomic_state_helper.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c index c7eb3ce8c282..1a6f55329fee 100644 --- a/drivers/gpu/drm/drm_atomic_state_helper.c +++ b/drivers/gpu/drm/drm_atomic_state_helper.c @@ -952,15 +952,16 @@ EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state); * @state: bridge state to initialize * * Initializes the bridge state to default values. This is meant to be called * by the bridge &drm_bridge_funcs.atomic_reset hook for bridges that subclass * the bridge state. + * + * The object @state points to is assumed to have been initialized to zero. */ void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge, struct drm_bridge_state *state) { - memset(state, 0, sizeof(*state)); __drm_atomic_helper_private_obj_create_state(&bridge->base, &state->base); state->bridge = bridge; } EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset); -- 2.53.0