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 97850352FFA; Tue, 26 Aug 2025 14:34:31 +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=1756218871; cv=none; b=DDpoWUIMcJldRnpWOpql2MTKVhCjBBoZgO2d4tadiSTyn+kjaS59hvq2klI+0PDfMbRVyfrL64dhjeBf13jUnQrJxZschco9WPmO7te+8O8dZB4ou1lZOqHP9kqjZPYPSS+gMbTPm2K0uMAdhgxXdTTaqZqK643lDBCOva6Ka/c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756218871; c=relaxed/simple; bh=QC8xSLP21Oy1VYvZdHB4FYd1KxcXENXhMcxX1aiZKT0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ftb4WTiNvFZn0pW/WbXbw+439Uv97OxCfbVjm1H+9eWFlk7vEKlUVGpjdncfZULbEA4NMTNCE9/sKNf1ZUqUkFB91LCxFkfNyFA5uG0M9C+yEXFkxzuaUl3Bo+sBDAZKt4+AMU5rdILUcv9fB0aliEH2LzAjm4QwhuR712isHLM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FNUD90GA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FNUD90GA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27119C4CEF1; Tue, 26 Aug 2025 14:34:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756218871; bh=QC8xSLP21Oy1VYvZdHB4FYd1KxcXENXhMcxX1aiZKT0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FNUD90GAxCGx4FFdOp6WFy76KCGu/sGUVtDAqycB+8cXXggSTMEliRLaNxdekD4ho YSKZ2TlVjOHwxR+aX7Tt3QPDLBYBx76cLSxRpc+i95RvU3x8q0lJiYsswfVAGwXqKI mM83G7fQfUGwi87kUDv8c2SRP2YrWwiKJR2ZKWGY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiayi Li , "Rafael J. Wysocki" Subject: [PATCH 5.4 166/403] ACPI: processor: perflib: Fix initial _PPC limit application Date: Tue, 26 Aug 2025 13:08:12 +0200 Message-ID: <20250826110911.476000622@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110905.607690791@linuxfoundation.org> References: <20250826110905.607690791@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiayi Li commit d33bd88ac0ebb49e7f7c8f29a8c7ee9eae85d765 upstream. If the BIOS sets a _PPC frequency limit upfront, it will fail to take effect due to a call ordering issue. Namely, freq_qos_update_request() is called before freq_qos_add_request() for the given request causing the constraint update to be ignored. The call sequence in question is as follows: cpufreq_policy_online() acpi_cpufreq_cpu_init() acpi_processor_register_performance() acpi_processor_get_performance_info() acpi_processor_get_platform_limit() freq_qos_update_request(&perflib_req) <- inactive QoS request blocking_notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_CREATE_POLICY) acpi_processor_notifier() acpi_processor_ppc_init() freq_qos_add_request(&perflib_req) <- QoS request activation Address this by adding an acpi_processor_get_platform_limit() call to acpi_processor_ppc_init(), after the perflib_req activation via freq_qos_add_request(), which causes the initial _PPC limit to be picked up as appropriate. However, also ensure that the _PPC limit will not be picked up in the cases when the cpufreq driver does not call acpi_processor_register_performance() by adding a pr->performance check to the related_cpus loop in acpi_processor_ppc_init(). Fixes: d15ce412737a ("ACPI: cpufreq: Switch to QoS requests instead of cpufreq notifier") Signed-off-by: Jiayi Li Link: https://patch.msgid.link/20250721032606.3459369-1-lijiayi@kylinos.cn [ rjw: Consolidate pr-related checks in acpi_processor_ppc_init() ] [ rjw: Subject and changelog adjustments ] Cc: 5.4+ # 5.4+: 2d8b39a62a5d ACPI: processor: Avoid NULL pointer dereferences at init time Cc: 5.4+ # 5.4+: 3000ce3c52f8 cpufreq: Use per-policy frequency QoS Cc: 5.4+ # 5.4+: a1bb46c36ce3 ACPI: processor: Add QoS requests for all CPUs Cc: 5.4+ # 5.4+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/processor_perflib.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -176,11 +176,14 @@ void acpi_processor_ppc_init(struct cpuf { unsigned int cpu; + if (ignore_ppc == 1) + return; + for_each_cpu(cpu, policy->related_cpus) { struct acpi_processor *pr = per_cpu(processors, cpu); int ret; - if (!pr) + if (!pr || !pr->performance) continue; /* @@ -196,6 +199,11 @@ void acpi_processor_ppc_init(struct cpuf if (ret < 0) pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu, ret); + + ret = acpi_processor_get_platform_limit(pr); + if (ret) + pr_err("Failed to update freq constraint for CPU%d (%d)\n", + cpu, ret); } }