From nobody Thu Nov 28 20:46:27 2024 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 25C3279FE; Sun, 29 Sep 2024 06:10:28 +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=1727590228; cv=none; b=ZILSuIHCKxemV0VyrqR0ZBUQj9Ip5Gko9fZpGhrf0/XApsPae3C5Vh+HPKoc4zpLzi77dbIMVwQr+uvr254kZBYFaaWfP/zl0U+0hYdCsSqCS/lvj16sZOdC7hOp4FlQkbzLXtO7a6CU9wMx0uCFlTwZOBXgdq2TdUmAgNJ7RXE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727590228; c=relaxed/simple; bh=7Fuox0/hODh+msXZV7oOranhdZQ4QHJP/cN1MxKp+98=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=aoid8FhFaghA8XPL1nRsx4MASuVuopGfNAsVwqbT0fjK2VD/U9PN33aqDTYhSdc37C6fZcOf/wCUzxIrvpqm68OxZ2qxgch1MHyrhPMJdsLdCQuF1Wum7Wfo5sI2g4l8LejwRqOpTZYfULlaYITObP03R1ER0qYu7eW6sezw0Fs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YjM3FtzD; 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="YjM3FtzD" Received: by smtp.kernel.org (Postfix) with ESMTPS id D7BCFC4CECE; Sun, 29 Sep 2024 06:10:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727590227; bh=7Fuox0/hODh+msXZV7oOranhdZQ4QHJP/cN1MxKp+98=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=YjM3FtzDabtKeBCpaRoyYb8f9EAXxa87YUUXVMu0J28eMjE6b7WunAaFPX5n/XZlI RtsXmQ+RxyHdVyTxXBczKq9K+FwfObVrJuqnWE6CcYsWRUMFLukEh0u9zD9xtqdq27 WSfBRokO/AkF1FBUbxbfaBWApVAI7pEKSer+hECXsvBCwvwnBQPLpMX271QZXYlG+Y w+esBgxFOuQNDOqGu+KNskrG/P/8KJ3YkVpSrWtWEriFG2VqsZ1CaU0yOJZHcoIHVB 9tnlc8nmqqn+759ZqIYfCqlfwB45xZv1pqx8QAvs93sShqD0cVb5VIEdes378sfwF1 mNLt16AvvpM2w== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1133CF6495; Sun, 29 Sep 2024 06:10:27 +0000 (UTC) From: Chuan Liu via B4 Relay Date: Sun, 29 Sep 2024 14:10:05 +0800 Subject: [PATCH 1/2] clk: Fix the CLK_IGNORE_UNUSED failure issue 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: quoted-printable Message-Id: <20240929-fix_glitch_free-v1-1-22f9c36b7edf@amlogic.com> References: <20240929-fix_glitch_free-v1-0-22f9c36b7edf@amlogic.com> In-Reply-To: <20240929-fix_glitch_free-v1-0-22f9c36b7edf@amlogic.com> To: Michael Turquette , Stephen Boyd , Neil Armstrong , Jerome Brunet , Kevin Hilman , Martin Blumenstingl Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Chuan Liu X-Mailer: b4 0.14.1 X-Developer-Signature: v=1; a=ed25519-sha256; t=1727590225; l=3496; i=chuan.liu@amlogic.com; s=20240902; h=from:subject:message-id; bh=j5nGks4RjMSPPYGFi+WoyylasN/sh7VgSzlGbwQyCJI=; b=QtvHpMbFuOIo/UK7CYtXIo11eZTGd+CWmoLcQrFkTWX/ZNF71z6QjhvRubudSx/KOMxNYM3TQ rCW5pbw2T0bCkhikgDPU6TxTQ7bPJUSAs/vbPKX2cfp1JR8FR89SO4f X-Developer-Key: i=chuan.liu@amlogic.com; a=ed25519; pk=fnKDB+81SoWGKW2GJNFkKy/ULvsDmJZRGBE7pR5Xcpo= X-Endpoint-Received: by B4 Relay for chuan.liu@amlogic.com/20240902 with auth_id=203 X-Original-From: Chuan Liu Reply-To: chuan.liu@amlogic.com From: Chuan Liu When the clk_disable_unused_subtree() function disables an unused clock, if CLK_OPS_PARENT_ENABLE is configured on the clock, clk_core_prepare_enable() and clk_core_disable_unprepare() are called directly, and these two functions do not determine CLK_IGNORE_UNUSED, This causes the clock to be disabled even if CLK_IGNORE_UNUSED is configured when clk_core_disable_unprepare() is called. Two new functions clk_disable_unprepare_unused() and clk_prepare_enable_unused() are added to resolve the preceding situation. The CLK_IGNORE_UNUSED judgment logic is added to these two functions. To prevent clock configuration CLK_IGNORE_UNUSED from possible failure. Change-Id: I56943e17b86436254f07d9b8cdbc35599328d519 Signed-off-by: Chuan Liu --- drivers/clk/clk.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++= ++-- 1 file changed, 65 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 285ed1ad8a37..5d3316699b57 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -94,6 +94,7 @@ struct clk_core { struct hlist_node debug_node; #endif struct kref ref; + bool ignore_enabled; }; =20 #define CREATE_TRACE_POINTS @@ -1479,6 +1480,68 @@ static void __init clk_unprepare_unused_subtree(stru= ct clk_core *core) } } =20 +static void __init clk_disable_unprepare_unused(struct clk_core *core) +{ + unsigned long flags; + + lockdep_assert_held(&prepare_lock); + + if (!core) + return; + + if ((core->enable_count =3D=3D 0) && core->ops->disable && + !core->ignore_enabled) { + flags =3D clk_enable_lock(); + core->ops->disable(core->hw); + clk_enable_unlock(flags); + } + + if ((core->prepare_count =3D=3D 0) && core->ops->unprepare && + !core->ignore_enabled) + core->ops->unprepare(core->hw); + + core->ignore_enabled =3D false; + + clk_disable_unprepare_unused(core->parent); +} + +static int __init clk_prepare_enable_unused(struct clk_core *core) +{ + int ret =3D 0; + unsigned long flags; + + lockdep_assert_held(&prepare_lock); + + if (!core) + return 0; + + ret =3D clk_prepare_enable_unused(core->parent); + if (ret) + return ret; + + if ((core->flags & CLK_IGNORE_UNUSED) && clk_core_is_enabled(core)) + core->ignore_enabled =3D true; + + if ((core->prepare_count =3D=3D 0) && core->ops->prepare) { + ret =3D core->ops->prepare(core->hw); + if (ret) + goto disable_unprepare; + } + + if ((core->enable_count =3D=3D 0) && core->ops->enable) { + flags =3D clk_enable_lock(); + ret =3D core->ops->enable(core->hw); + clk_enable_unlock(flags); + if (ret) + goto disable_unprepare; + } + + return 0; +disable_unprepare: + clk_disable_unprepare_unused(core->parent); + return ret; +} + static void __init clk_disable_unused_subtree(struct clk_core *core) { struct clk_core *child; @@ -1490,7 +1553,7 @@ static void __init clk_disable_unused_subtree(struct = clk_core *core) clk_disable_unused_subtree(child); =20 if (core->flags & CLK_OPS_PARENT_ENABLE) - clk_core_prepare_enable(core->parent); + clk_prepare_enable_unused(core->parent); =20 flags =3D clk_enable_lock(); =20 @@ -1517,7 +1580,7 @@ static void __init clk_disable_unused_subtree(struct = clk_core *core) unlock_out: clk_enable_unlock(flags); if (core->flags & CLK_OPS_PARENT_ENABLE) - clk_core_disable_unprepare(core->parent); + clk_disable_unprepare_unused(core->parent); } =20 static bool clk_ignore_unused __initdata; --=20 2.42.0