From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 D2E29302753 for ; Tue, 16 Jun 2026 21:10:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781644240; cv=none; b=Aqe7vWilcffOWidE6tfTe40DshfOAWZZRN3LEFIzttZ7Nm2a5IrTJiRQiX0yOyNubKfdSlEb7QMbGpIm+XmM8XtVUrP82lyvNDRaeCVIvJ6BOOXmcR6uhCL2zXs25/GjbsbA5TD5bF7aAklTJsYjUVADUIBTK3P20g10Dq//HZE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781644240; c=relaxed/simple; bh=J7gYEeWCxB1tJhgelNOaDUWno2W5LahEOqzwNzbFLVk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=O29jK3yj8hZ+eWolTKgyfsuK3SvWWCBQIwHkBNj/wMF7hpavkdAO0p+ySND8TqRDzbjtoQfAHFdUskGKRVxh9IKQm8JKcv/rYAcqgl7z90eB2jQ52K+T+zjvhJxo2ItM0PRxl/OPxVYAu+6HR9J+sJE5rFSyRDtuSgSGwqgL354= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=ODg3mbbd; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=G5s7GpCG; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ODg3mbbd"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="G5s7GpCG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1781644237; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BjvCrBMszrMJ2Knwf+augk31h+3piL8f3cGGXhlSVYM=; b=ODg3mbbd8D0kDxGLw4g/KwHw2TYN3XaDCPSIRdjPcz9QLi4tMoG1zEtpMbd1ryk2TlbvpT OtIcHYtfELcAxVmzDENUXHhFOikAT9NSdBKtsr2O2QyOxNcNSovCbUIvOMMexuD+1EZy1d 7R/qPDIgtX35WEEgZ5VYnO2VuBY6Yj0= Received: from mail-qv1-f72.google.com (mail-qv1-f72.google.com [209.85.219.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-661-9kwWLsG6OCOMCdMNaMvDpA-1; Tue, 16 Jun 2026 17:10:35 -0400 X-MC-Unique: 9kwWLsG6OCOMCdMNaMvDpA-1 X-Mimecast-MFC-AGG-ID: 9kwWLsG6OCOMCdMNaMvDpA_1781644235 Received: by mail-qv1-f72.google.com with SMTP id 6a1803df08f44-8cecf8bb835so79046356d6.1 for ; Tue, 16 Jun 2026 14:10:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1781644235; x=1782249035; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=BjvCrBMszrMJ2Knwf+augk31h+3piL8f3cGGXhlSVYM=; b=G5s7GpCG+dw9eXWgstN+KV0XzL5z0UJWsadAsGoM1yG3ptifnxkZrNpeZDh1iVqoH0 3HsLMUEVOjxQy5O1cn3ETM1kRpxU6FWPvXQYqDdkpLvAeu8IYaIZgzQVX4qZ6W16we3F kiAUy/14rGM6bXPKSvexUr8UerQOpEXLIuDwAF+gAuXS/5LPEBJkG403GEw9fSan35i9 7SQz/HniBtT9MgX6DJ5qn7VcOCTlHTixaHmSe+61mSK+JzjIdZNlQxMfvKGk3gs0XNHW NU7sP6M5sCX/s7TezKKdNvGnMrwm6zH2b/8oM4kvPgM7ivHpyfmHbHpO36pOHBGgFudb 42gg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781644235; x=1782249035; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-gg:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=BjvCrBMszrMJ2Knwf+augk31h+3piL8f3cGGXhlSVYM=; b=i6KiqXWqcChqC2+76laidEbDy8I10wssfmObG5O/8pRtcAesyRC2ajX8QS4E6v59Bx MGMSziKUHA4gZ7I9TxSnMX5uqsim9OcJ9XViNT1ivLprSaGpN6UcRI7OduRMKaBhHKdi XSPUPwSOF77fSIyVqLYvdxs4jM3IW62qkUNHTQpVwf2/SgN4bUnbMjEOL/gs3EaKGs2Y 0MFL+/2JvCmKt7fKJfBfk5Mpq0I/AGH0ixNwxKhD6HUMn0lfJlHMcg4pnnkeVj5WDMfE qu9iZciLC4zo1e7y/ELl0W7OlGPNJ52ftg5m4TKgjutW0B3XHVpLc55rtKAwhmGRP5Vo dmKw== X-Forwarded-Encrypted: i=1; AFNElJ+ILVFLG9IurG7l0WSYLgdeneu8L5TEyYKoZq/YhAQ5LKiQh9s7qAk7y8s4je/KJUXw/RhR7rgY2VmLAtE=@vger.kernel.org X-Gm-Message-State: AOJu0Yx5foBBICbNu+iLZTfCchE92LDl4KrISFIWtdjzu5Th5klaQ3kN OCa12R9BjtY4/4LYKUx8Bu3jrLGh8KGWQqQh3q4CTvKviRf5yACogZk/f0zZwit7LzVtwVq4m9u SiU9f70v5FApSq1rdva8rsRCxw0jPjaunMATpGDBcHe2J7+Mpy+1emowqtG/HiLOUvg== X-Gm-Gg: Acq92OGwqPqtaiknm+kY2c46gUlZdgim/y9nUy3bxGmCAuYai+eZWzUyEAMH0ykOO9K IHbMpvszJJLK/Ev9Fbv06Dk11+t3Z7LEii+6WOR1Dg8mLuxaipqs9NULn4eMjEFrTn2XsVstxIX M3Pr6x/xnrJZUqtP2MihmAbkvPvwugdKV3eMhSmxclC8/x8b2Pp9aUpJ3r9whZ3NGtj9uyIXTeT 6aIQAX4UgkTppKWlM+NzBfl0pZuLZ6nXyuWpU59TOnhRB5NYSDhFgYkGM14VFkVNzLuhPkRgOuC eEbDMx3V1D7vA6WnQrgq184HzQeMT8ME4CVFUcZE6T+UM7RaOYx2vki3qwClhWnqhLxQvH9BDUx gK6UaoMoMVW4KaaKZ77si9Z9RjbaeNVMnUAK00LOpArrswg5eh41Br731hGBhow== X-Received: by 2002:a05:6214:dc1:b0:8ca:ee3:6ea9 with SMTP id 6a1803df08f44-8db83137b85mr14869136d6.20.1781644235104; Tue, 16 Jun 2026 14:10:35 -0700 (PDT) X-Received: by 2002:a05:6214:dc1:b0:8ca:ee3:6ea9 with SMTP id 6a1803df08f44-8db83137b85mr14864746d6.20.1781644231926; Tue, 16 Jun 2026 14:10:31 -0700 (PDT) Received: from [192.168.1.15] (c-73-183-52-120.hsd1.pa.comcast.net. [73.183.52.120]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8d9f122b21bsm43742846d6.4.2026.06.16.14.10.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jun 2026 14:10:31 -0700 (PDT) From: Brian Masney Date: Tue, 16 Jun 2026 17:09:47 -0400 Subject: [PATCH v2 5/5] clk: implement sync_state support 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: 8bit Message-Id: <20260616-clk-sync-state-v2-5-15f82c64d95c@redhat.com> References: <20260616-clk-sync-state-v2-0-15f82c64d95c@redhat.com> In-Reply-To: <20260616-clk-sync-state-v2-0-15f82c64d95c@redhat.com> To: Saravana Kannan , Abel Vesa , Maxime Ripard , Michael Turquette , Stephen Boyd , Russell King , Bjorn Andersson , Hans de Goede , Konrad Dybcio , Dmitry Baryshkov Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Brian Masney , Jens Glathe X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=8302; i=bmasney@redhat.com; s=20250903; h=from:subject:message-id; bh=J7gYEeWCxB1tJhgelNOaDUWno2W5LahEOqzwNzbFLVk=; b=owGbwMvMwCW2/dJd9di6A+2Mp9WSGLIMd+9ZZTSpv2+qfIN0QZzpS14dZQV2jxQ77bXvuKafv s0R9a+po5SFQYyLQVZMkWVJrlFBROoq23t3NFlg5rAygQxh4OIUgImcDGRk6DvyRl26aAfTX/uf hovu3I5muH/KqP/qwZ0OUyK+n1+u95ORYfH/Mju+FU+ShENM+0/UxaecNVjopqhtKL/7j8c8du/ vjAA= X-Developer-Key: i=bmasney@redhat.com; a=openpgp; fpr=A46D32705865AA3DDEDC2904B7D2DD275D7EC087 The existing support for disabling unused clks runs in the late initcall stage, and it has been known for a long time that this is broken since it runs too early in the boot up process. It doesn't work for kernel modules, and it also doesn't work if all of the consumers haven't fully probed yet. Folks have long recommended to boot certain platforms with clk_ignore_unused to work around issues with disabling unused clks. Let's go ahead and add a framework-level sync_state callback for the clk subsystem. If a driver doesn't have a sync_state callback configured, which is the 99+% use case today, then let's set it up to use the clk_sync_state() introduced in this commit so that no driver changes are needed. At the time of this writing, there are currently only 7 clk drivers that implement sync_state, and all are Qualcomm SoCs where they interact with the interconnect framework via icc_sync_state(). A shared helper has been created for this platform that calls clk_sync_state(). It is expected that any new clk drivers that want to implement their own sync_state will also need to call clk_sync_state() at the end of their custom sync_state callback. There will be several stages of disabling unused clks: - The first phase will be executed at late_initcall and it will only disable unused clks that do not have a struct dev. - The sync_state callback will be invoked for each clk driver once all consumers have probed. This is based on previous attempts by Saravana Kannan and Abel Vesa that are linked below. This change was tested on a Thinkpad x13s laptop. [ 0.308051] clk: Disabling unused clocks not associated with a device [ 6.541069] qcom_aoss_qmp c300000.power-management: clk: Disabling unused clocks [ 6.843310] qcom-qmp-pcie-phy 1c24000.phy: clk: Disabling unused clocks [ 7.604556] qcom-qmp-pcie-phy 1c14000.phy: clk: Disabling unused clocks [ 8.446161] qcom-qmp-usb-phy 88f1000.phy: clk: Disabling unused clocks [ 8.446293] qcom-qmp-usb-phy 88ef000.phy: clk: Disabling unused clocks [ 8.546067] qcom-qmp-combo-phy 88eb000.phy: clk: Disabling unused clocks [ 8.546203] qcom-qmp-combo-phy 8903000.phy: clk: Disabling unused clocks [ 8.546254] qcom-edp-phy aec5a00.phy: clk: Disabling unused clocks [ 15.436834] qcom-cpufreq-hw 18591000.cpufreq: clk: Disabling unused clocks [ 15.436953] clk-rpmh 18200000.rsc:clock-controller: clk: Disabling unused clocks [ 15.723348] qcom-qmp-pcie-phy 1c06000.phy: clk: Disabling unused clocks [ 21.063241] q6prm-lpass-clock 3000000.remoteproc:glink-edge:gpr:service@2:clock-controller: clk: Disabling unused clocks [ 21.081996] va_macro 3370000.codec: clk: Disabling unused clocks [ 21.092740] rx_macro 3200000.rxmacro: clk: Disabling unused clocks [ 21.118261] wsa_macro 3240000.codec: clk: Disabling unused clocks [ 21.128758] tx_macro 3220000.txmacro: clk: Disabling unused clocks Tested-by: Jens Glathe Signed-off-by: Brian Masney Link: https://www.youtube.com/watch?v=tXYzM8yLIQA Link: https://lore.kernel.org/all/20210407034456.516204-1-saravanak@google.com/ Link: https://lore.kernel.org/all/20221227204528.1899863-1-abel.vesa@linaro.org/ --- drivers/clk/clk.c | 72 +++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 59 insertions(+), 13 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 9cb2b42d1be4..7a15cceec620 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1442,14 +1442,39 @@ static void clk_core_disable_unprepare(struct clk_core *core) clk_core_unprepare_lock(core); } -static void __init clk_unprepare_unused_subtree(struct clk_core *core) +/* + * Returns true if @core should be skipped during an unused-clock sweep for + * @dev. When @dev is NULL the sweep is the global late_initcall pass; when + * @dev is non-NULL the sweep is a per-device sync_state pass. + */ +static bool clk_core_skip_unused(struct clk_core *core, struct device *dev) +{ + /* + * At late_initcall, skip clocks that belong to a device — they will be + * handled at sync_state time. + */ + if (!dev && core->dev) + return true; + + /* When called from sync_state, only process clocks for this device. */ + if (dev && core->dev != dev) + return true; + + return false; +} + +static void clk_unprepare_unused_subtree(struct clk_core *core, + struct device *dev) { struct clk_core *child; lockdep_assert_held(&prepare_lock); hlist_for_each_entry(child, &core->children, child_node) - clk_unprepare_unused_subtree(child); + clk_unprepare_unused_subtree(child, dev); + + if (clk_core_skip_unused(core, dev)) + return; if (core->prepare_count) return; @@ -1467,7 +1492,8 @@ static void __init clk_unprepare_unused_subtree(struct clk_core *core) } } -static void __init clk_disable_unused_subtree(struct clk_core *core) +static void clk_disable_unused_subtree(struct clk_core *core, + struct device *dev) { struct clk_core *child; unsigned long flags; @@ -1475,7 +1501,10 @@ static void __init clk_disable_unused_subtree(struct clk_core *core) lockdep_assert_held(&prepare_lock); hlist_for_each_entry(child, &core->children, child_node) - clk_disable_unused_subtree(child); + clk_disable_unused_subtree(child, dev); + + if (clk_core_skip_unused(core, dev)) + return; if (core->flags & CLK_OPS_PARENT_ENABLE) clk_core_prepare_enable(core->parent); @@ -1508,7 +1537,7 @@ static void __init clk_disable_unused_subtree(struct clk_core *core) clk_core_disable_unprepare(core->parent); } -static bool clk_ignore_unused __initdata; +static bool clk_ignore_unused; static int __init clk_ignore_unused_setup(char *__unused) { clk_ignore_unused = true; @@ -1516,7 +1545,7 @@ static int __init clk_ignore_unused_setup(char *__unused) } __setup("clk_ignore_unused", clk_ignore_unused_setup); -static int __init clk_disable_unused(void) +static int __clk_disable_unused(struct device *dev) { struct clk_core *core; int ret; @@ -1526,7 +1555,10 @@ static int __init clk_disable_unused(void) return 0; } - pr_info("clk: Disabling unused clocks\n"); + if (dev) + dev_info(dev, "clk: Disabling unused clocks\n"); + else + pr_info("clk: Disabling unused clocks not associated with a device\n"); ret = clk_pm_runtime_get_all(); if (ret) @@ -1538,16 +1570,16 @@ static int __init clk_disable_unused(void) clk_prepare_lock(); hlist_for_each_entry(core, &clk_root_list, child_node) - clk_disable_unused_subtree(core); + clk_disable_unused_subtree(core, dev); hlist_for_each_entry(core, &clk_orphan_list, child_node) - clk_disable_unused_subtree(core); + clk_disable_unused_subtree(core, dev); hlist_for_each_entry(core, &clk_root_list, child_node) - clk_unprepare_unused_subtree(core); + clk_unprepare_unused_subtree(core, dev); hlist_for_each_entry(core, &clk_orphan_list, child_node) - clk_unprepare_unused_subtree(core); + clk_unprepare_unused_subtree(core, dev); clk_prepare_unlock(); @@ -1555,11 +1587,16 @@ static int __init clk_disable_unused(void) return 0; } + +static int __init clk_disable_unused(void) +{ + return __clk_disable_unused(NULL); +} late_initcall_sync(clk_disable_unused); void clk_sync_state(struct device *dev) { - /* Will fill in */ + __clk_disable_unused(dev); } EXPORT_SYMBOL_GPL(clk_sync_state); @@ -4345,8 +4382,17 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) core->dev = dev; clk_pm_runtime_init(core); core->of_node = np; - if (dev && dev->driver) + if (dev && dev->driver) { core->owner = dev->driver->owner; + + /* + * If a clk provider sets their own sync_state, then it needs to + * also call clk_sync_state(). dev_set_drv_sync_state() won't + * overwrite the sync_state callback, and this call will fail + * with -EBUSY. + */ + dev_set_drv_sync_state(dev, clk_sync_state); + } core->hw = hw; core->flags = init->flags; core->num_parents = init->num_parents; -- 2.54.0