From nobody Sat Feb 7 17:41:37 2026 Received: from sender4-pp-f119.zoho.com (sender4-pp-f119.zoho.com [136.143.188.119]) (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 7D60D34FF75; Wed, 28 Jan 2026 14:12:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.119 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769609535; cv=pass; b=sNlvT/6FV5/tr9zLMVYyrsDwMGEIfm10hgbzIDfQjJeJRv9iKRtlLh9aR82yZXzzDRwuuEISQR9G/qqeiYVTMj8fE3OW4QLApCrKoxUG32zBWR3cjnywfGH4b+i7L5lKupp18qxpACb9fjwC86WULXeAlkWVG3gMNQbK1+uelNM= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769609535; c=relaxed/simple; bh=IVMZB9Tk9NiTAUjmRFIl99L8zNhrABXDdDcTizSXmiw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=GLxGlGgRcJQOCjpUlue4alfvuFrcrEToUfZQsL+SEAbVyDsQXIeP9iVx/kUcj+eXi7Xk0t7uPW5JCfsg+NJZSCBa+Fz6cY2oz8f/obHPVidDOC0+R6/1IGdKy9/ZlWuTkg8lEtmkgi0v3CCgc34nASIIomo0VM0M4f+5NyDoXH8= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=nicolas.frattaroli@collabora.com header.b=K6YN9xrt; arc=pass smtp.client-ip=136.143.188.119 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=nicolas.frattaroli@collabora.com header.b="K6YN9xrt" ARC-Seal: i=1; a=rsa-sha256; t=1769609502; cv=none; d=zohomail.com; s=zohoarc; b=C2e+E4pPdtRU0uXKZqe0nGXZf0SD6zxByFcRW+JwfXGQnTkXetHKuYPcnJ0MqYB60iGKY+Kuq8UEkdD8kelCKUfOZ0M4ghaLWTq7FOBrpzOZYFlEb8NKF2r56PYF+XvCqiyux3DLMH8lFfyKjEf1sEM0mdGSf5S02U6XEf6krTc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1769609502; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=06r3ry7I70lRQ3WUitTO3gPI56HJOgQVtCUV6n6r200=; b=XeiaJatdZKx0rA2QFkUb/OdlU4exgFCcrssdGOQzKfxH3TlKLmXRqrqOSO4joicpbyRdOy2RH6BF9OJfjVPqBNpKgIJeQKhsAEconTVJZEcGmVC/QQqObSezSKErn49tqmx9X934TdB99Vefa7S8geJIbVlyDV7KZOmWbshr8Aw= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=nicolas.frattaroli@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1769609502; s=zohomail; d=collabora.com; i=nicolas.frattaroli@collabora.com; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:In-Reply-To:References:MIME-Version:Content-Transfer-Encoding:Content-Type:Message-Id:Reply-To; bh=06r3ry7I70lRQ3WUitTO3gPI56HJOgQVtCUV6n6r200=; b=K6YN9xrtYa7BF8aF2GW5pAk0tIphh5M/0YPNQ9IsjnU6gA1m723rjekaC2ThSrBC BsNFXBL3E7Jka14k//5dnNQ0Q3uDKylIbgVlgfVdqEjZhlJNfH/In6iCjaRcU0imMkp 0dxE03fCnQ+EkKwmThtp26djyKpcWOL+IgvZt454= Received: by mx.zohomail.com with SMTPS id 1769609499860744.4033332740098; Wed, 28 Jan 2026 06:11:39 -0800 (PST) From: Nicolas Frattaroli To: AngeloGioacchino Del Regno , Chen-Yu Tsai , Chia-I Wu , Dong Aisheng , Laura Nao , Matthias Brugger , Michael Turquette , =?UTF-8?B?TsOtY29sYXMgRi4gIFIuICBBLg==?= Prado , Yassine Oudjana , Stephen Boyd , Alexander Stein Cc: kernel@collabora.com, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: Re: [PATCH RESEND v3 1/5] clk: Respect CLK_OPS_PARENT_ENABLE during recalc Date: Wed, 28 Jan 2026 15:11:33 +0100 Message-ID: <5791016.31r3eYUQgx@workhorse> In-Reply-To: <6239343.lOV4Wx5bFT@steina-w> References: <20251215-mtk-pll-rpm-v3-0-5afb3191e869@collabora.com> <176913273374.4027.10690199843699119944@lazor> <6239343.lOV4Wx5bFT@steina-w> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On Tuesday, 27 January 2026 15:55:29 Central European Standard Time Alexand= er Stein wrote: > Hello, >=20 > Am Freitag, 23. Januar 2026, 02:45:33 CET schrieb Stephen Boyd: > > Quoting Nicolas Frattaroli (2025-12-15 03:23:58) > > > When CLK_OPS_PARENT_ENABLE was introduced, it guarded various clock > > > operations, such as setting the rate or switching parents. However, > > > another operation that can and often does touch actual hardware state= is > > > recalc_rate, which may also be affected by such a dependency. > > >=20 > > > Add parent enables/disables where the recalc_rate op is called direct= ly. > > >=20 > > > Fixes: fc8726a2c021 ("clk: core: support clocks which requires parent= s enable (part 2)") > > > Fixes: a4b3518d146f ("clk: core: support clocks which requires parent= s enable (part 1)") > > > Reviewed-by: AngeloGioacchino Del Regno > > > Reviewed-by: Chen-Yu Tsai > > > Signed-off-by: Nicolas Frattaroli > > > --- > >=20 > > Applied to clk-next >=20 > Unfortunately this breaks my board TQMa8MPxL+MBa8MPxL on next-20260126. > Last lines on bootlog (earlycon is necessary) > > [ 1.175639] Initialise system trusted keyrings > > [ 1.178907] workingset: timestamp_bits=3D42 max_order=3D19 bucket_or= der=3D0 > > [ 1.185822] NFS: Registering the id_resolver key type > > [ 1.190295] Key type id_resolver registered > > [ 1.194473] Key type id_legacy registered > > [ 1.198515] nfs4filelayout_init: NFSv4 File Layout Driver Registerin= g... > > [ 1.205235] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver > > Registering... [ 1.213235] cryptd: max_cpu_qlen set to 1000 > > [ 1.274689] Key type asymmetric registered > > [ 1.275939] Asymmetric key parser 'x509' registered > > [ 1.280896] Block layer SCSI generic (bsg) driver version 0.4 loaded > > (major 242) [ 1.288278] io scheduler mq-deadline registered > > [ 1.292840] io scheduler kyber registered > > [ 1.299245] ledtrig-cpu: registered to indicate activity on CPUs >=20 > Reverting commit 669917676e93fca5ea3c66fc9539830312bec58e fixes the probl= em. Hi Alexander, sorry for breaking -next. Can you try the following patch to print which clock+parent is causing the hang on your platform? --- diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 1b0f9d567f48..fa1443517768 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1921,13 +1921,21 @@ static unsigned long clk_recalc(struct clk_core *co= re, unsigned long rate =3D parent_rate; =20 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) { - if (core->flags & CLK_OPS_PARENT_ENABLE) + if (core->flags & CLK_OPS_PARENT_ENABLE) { + pr_info("%s: enabling parent %s for %s\n", __func__, + core->parent ? core->parent->name : "(null)", + core->name); clk_core_prepare_enable(core->parent); + } =20 rate =3D core->ops->recalc_rate(core->hw, parent_rate); =20 - if (core->flags & CLK_OPS_PARENT_ENABLE) + if (core->flags & CLK_OPS_PARENT_ENABLE) { + pr_info("%s: disabling parent %s for %s\n", __func__, + core->parent ? core->parent->name : "(null)", + core->name); clk_core_disable_unprepare(core->parent); + } =20 clk_pm_runtime_put(core); } @@ -4038,8 +4046,12 @@ static int __clk_core_init(struct clk_core *core) */ clk_core_update_duty_cycle_nolock(core); =20 - if (core->flags & CLK_OPS_PARENT_ENABLE) + if (core->flags & CLK_OPS_PARENT_ENABLE) { + pr_info("%s: enabling parent %s for %s\n", __func__, + core->parent ? core->parent->name : "(null)", + core->name); clk_core_prepare_enable(core->parent); + } =20 /* * Set clk's rate. The preferred method is to use .recalc_rate. For @@ -4056,8 +4068,12 @@ static int __clk_core_init(struct clk_core *core) rate =3D 0; core->rate =3D core->req_rate =3D rate; =20 - if (core->flags & CLK_OPS_PARENT_ENABLE) + if (core->flags & CLK_OPS_PARENT_ENABLE) { + pr_info("%s: disabling parent %s for %s\n", __func__, + core->parent ? core->parent->name : "(null)", + core->name); clk_core_disable_unprepare(core->parent); + } =20 /* * Enable CLK_IS_CRITICAL clocks so newly added critical clocks --- Thanks for reporting this. Kind regards, Nicolas Frattaroli >=20 > Best regards, > Alexander >