From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) (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 4F8653126D0 for ; Tue, 9 Jun 2026 06:26:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780986413; cv=none; b=WKzqeys1OdCQZ/qRS7w9eSlFXmGv3W6Xz+0Z20xoPYBw5F4+GwCr1++fGYRAz/CBPFD/oCasUJWiI1gtjaOszKpN4IghvBOQUePZ6PJoc3M4KiW6dzb5puL7ba4cMMB9cBo2YAikkIkwV+ftsqvAuU8cMSmEEb5ke4GFOZn2F7s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780986413; c=relaxed/simple; bh=UXvgZ5i39WFb+rtXwEcMt3I1NdMkQHw8ky5ZKPRvCR0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jcFHwCpmAVHVekNMgD9y8g8Bo8Ic1kUbyAdyVQ8hfqrH1hvlzg00II+rqvn8HwqrjNDxhdgaKQT9k/9VaFYM5GOvm7gBIFn1t1k4+xv/Lu3MHznOlbg7672hq9Mxn3qnVfthUNLGPiuS7N5kBRMQ/F2uBbnmdEjP4klIUNBiYVo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=hAcwtJDC; arc=none smtp.client-ip=95.215.58.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="hAcwtJDC" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1780986398; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QgWAksApTGvLxjW8jDqRXxXlqcSTxmsvhz5k9DI0lic=; b=hAcwtJDCWZFRSYLTEPue3KI/vBKMw7McXz6aBCAwYSHGbCZ8691Hb8Q9SEjvRfQxb72Tta DvZFdo/ENYvZXhMqWs/CaNmhp2HC/ZidkwGpdCsM2noviPsBOF++1vKdv+wycU7cucS29B gJe3i3hLPUY6TqgCUx2oYjH058D/AcI= From: Kaitao Cheng To: Andy Shevchenko , Muchun Song , Philipp Reisner , Lars Ellenberg , =?UTF-8?q?Christoph=20B=C3=B6hmwalder?= , Jens Axboe , Takashi Sakamoto , Andrzej Hajda , Neil Armstrong , Robert Foss , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , Christian Koenig , Huang Rui , Eddie James , Mark Brown , Maxime Coquelin , Alexandre Torgue , Laxman Dewangan , Thierry Reding , Jonathan Hunter , Sowjanya Komatineni , Davidlohr Bueso , "Paul E . McKenney" , Josh Triplett , Peter Zijlstra , Ingo Molnar , Will Deacon , Boqun Feng , Liam Girdwood , Jaroslav Kysela , Takashi Iwai Cc: Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Matthew Auld , Matthew Brost , Waiman Long , drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, linux1394-devel@lists.sourceforge.net, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-spi@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-tegra@vger.kernel.org, linux-sound@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , Randy Dunlap , Christian Brauner , David Howells , Luca Ceresoli , Kaitao Cheng , Kaitao Cheng Subject: [PATCH v2 03/14] drm/bridge: Open-code bridge chain list walks Date: Tue, 9 Jun 2026 14:25:15 +0800 Message-ID: <20260609062526.94907-1-kaitao.cheng@linux.dev> In-Reply-To: <20260609061347.93688-1-kaitao.cheng@linux.dev> References: <20260609061347.93688-1-kaitao.cheng@linux.dev> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Kaitao Cheng A later change will make list_for_each_entry_from() and list_for_each_entry_reverse() cache the next or previous element before entering the loop body. The bridge enable and disable ordering code adjusts its cursor to skip ranges that have already been handled. Keep those walks open-coded so the loop step observes the cursor selected by the body. This preserves the existing bridge ordering semantics and prepares the code for the list iterator update. Signed-off-by: Kaitao Cheng --- drivers/gpu/drm/drm_bridge.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index d6f512b73389..a538aabc4e0b 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -868,7 +868,8 @@ void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge, encoder = bridge->encoder; - list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + for (; !list_entry_is_head(bridge, &encoder->bridge_chain, chain_node); + bridge = list_next_entry(bridge, chain_node)) { limit = NULL; if (!list_is_last(&bridge->chain_node, &encoder->bridge_chain)) { @@ -962,7 +963,9 @@ void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge, encoder = bridge->encoder; - list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { + for (iter = list_last_entry(&encoder->bridge_chain, typeof(*iter), chain_node); + !list_entry_is_head(iter, &encoder->bridge_chain, chain_node); + iter = list_prev_entry(iter, chain_node)) { if (iter->pre_enable_prev_first) { next = iter; limit = bridge; -- 2.43.0