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 6059E35971 for ; Tue, 4 Nov 2025 06:46:50 +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=1762238811; cv=none; b=HOVwMRMqKghhDPM824nSOgWkCmTaZWed88LfQXbUzWz6vS/ByWAusfnZgho+x4p2XwPrI44i7kcrA0IW8sgc/GOwHzIHCt5u+Ui4ul/p/DSCkUlo+fGCwOnp912DGrvZhjS89hkKNYY0pnQWesyj/2PbMzfOd8z+RBKzSztcQL0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762238811; c=relaxed/simple; bh=eX3fIp/uaqJ5lCpgInWlyfHk9Lz/9PExRsF2X6i0tcc=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=J+h23IvpRe2AveO/IaYLJIp71/mMENG/gVX1JDh6EeFLmPZh0NgMr8zkyXWANSxH8HRmaV6Z18XGIw1AtTlN+4BnERQUBaECGW7wkDIPWBjarPtciUnKHsUTlk08ApZZPg4WO5kJMC1iZ9GxJeSh25C93VK7vZYivOr+dz4iNwg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MyuMPcdZ; 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="MyuMPcdZ" Received: by smtp.kernel.org (Postfix) with ESMTPS id EEE44C4CEF7 for ; Tue, 4 Nov 2025 06:46:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762238810; bh=eX3fIp/uaqJ5lCpgInWlyfHk9Lz/9PExRsF2X6i0tcc=; h=From:To:Subject:Date:In-Reply-To:References:From; b=MyuMPcdZu39DgB54V9+kXeE/1SWQxzkownRTA6bi8y/DuUD+XXvi551UcmUcjSB6S IHtLzP1OnKerM0R7BmmKP/8Z9GmaGO65v4cTf24DT75y1OH0lJQee8K/ayr4tdsvtQ wTUK8o+uUOPcNFRQyMHsmLAvHkO4MqIWxreBvoygFtk76QODsdmcJU9jVNUMeZjVKg E+d0a4r1xlA1nn8mqAjx18G68Fa9U30cbk8zqdfHUIkcX1kHXs51N2GzcG3AAeQz0e MAngl8cqg2P2NXSs+BMAEUARLvsnCaep3UoIyjQCMkctgTQPNJCiPYeqUS8rda1q2x 3haAbazhuvyVA== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id E8006C41612; Tue, 4 Nov 2025 06:46:49 +0000 (UTC) From: bugzilla-daemon@kernel.org To: linux-pm@vger.kernel.org Subject: [Bug 220715] [REGRESSION] AMD P-State fails with "_CPC object is not present" on AMD Zen 4 between 6.10 and 6.11 Date: Tue, 04 Nov 2025 06:46:49 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Power Management X-Bugzilla-Component: cpufreq X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: gautham.shenoy@gmail.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: linux-pm@vger.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D220715 Gautham R. Shenoy (gautham.shenoy@gmail.com) changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |gautham.shenoy@gmail.com --- Comment #16 from Gautham R. Shenoy (gautham.shenoy@gmail.com) --- I think Mario is on the right track in that the issue is because of failure= to detect something on a CPU that is present but not online. My hunch is that it is in amd_detect_prefcore() which checks if the number = of distinct highest_perf values in the system is greater than 1, but uses for_each_present_cpu() which fails when the system is booted with `nosmt=3Dforce`. The commit that introduces this code is 279f838a61f9 ("x8= 6/amd: Detect preferred cores in amd_get_boost_ratio_numerator()") which got merge= d in the upstream kernel 6.12. @Chris, if you don't mind, can you please try the following patch: diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c index 7047124490f6..d7c8ef1e354d 100644 --- a/arch/x86/kernel/acpi/cppc.c +++ b/arch/x86/kernel/acpi/cppc.c @@ -196,7 +196,7 @@ int amd_detect_prefcore(bool *detected) break; } - for_each_present_cpu(cpu) { + for_each_online_cpu(cpu) { u32 tmp; int ret; --=20 You may reply to this email to add a comment. You are receiving this mail because: You are the assignee for the bug.=