From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 16E561FF7C8 for ; Thu, 3 Sep 2026 17:19:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788455951; cv=none; b=ZdnFwYFWFZR0ZCytW8qTDPh5J3Jitrfk3I0HPF+11dD9bV/EhgGk2FBsGJMPYp0w3zUsqiqyLJZv21zTwIq5gDlS4F36M+vSNzkMVRjbIDUUaK33DExhXk+g2aZ7UX6aEh3MBpmOkz+Qzb0M+bXRZYIHs/zuVlItJMY5HmB1gkc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788455951; c=relaxed/simple; bh=QHxVQTSv4bcEr0VSUiqCmdmDu9gDesUNAGGtXT6tdpw=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=Y6Asb3QxRp7qBqvzb3/TibqvHVgsrwIuB0jeDW6ATPUZ6xO9YXMOxXrNrvdz5wTvwbBCA2biF06jskpO20O7M4nxt1/7uSEAIrynEGlr6C3yMsMVa2BFGJhN1tCn2VdKB2yweDqqx5+oXjrpvjBpkGu1DKzKi0MSO2gLRp9/NB8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HCGVdaRr; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HCGVdaRr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7F061F000E9; Thu, 3 Sep 2026 17:19:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788455949; bh=nL+SX72WA1oBs/j59kUk9NFUID+ez4eEFxsL/H/fj2Y=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=HCGVdaRr6aJd+y6ZY05k6EGVS3Pu8gsbwgR2c3BpwHCaCN6KD+b9KVT74Ht+MhkYR xWX2ehIdclSKPHefVvbAbV2kCcdGeb26qT1EmCMhX23pyXs4E87hD3SSOKGGP2joXv cpqodrvkfmzB1HgXroamd12di+dK/Sfz/PQ89rhRVjX4EsIZ/QEVWwtmhK4lrgZ0hY jFa+VpzTNlBYaNiZnGmz0bjj9DrMI9CUXs/eT7JeKHuKPOf7iOtwv7zodhT3mR6xuH yUHLAr7NEn2Nd2HmFK2DlCGSFqhEZ0diJ2uBudO2zcFjpNiUNqLAuxU+l1yzilsAVZ VcsjLYLOp+TiQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 1/4] ACPI: PM: Drop parent state update from acpi_device_get_power() Reply-To: sashiko-reviews@lists.linux.dev To: "Rafael J. Wysocki" Cc: linux-pci@vger.kernel.org In-Reply-To: <5147279.31r3eYUQgx@rafael.j.wysocki> References: <6044499.DvuYhMxLoT@rafael.j.wysocki> <5147279.31r3eYUQgx@rafael.j.wysocki> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 03 Sep 2026 17:19:09 +0000 Message-Id: <20260903171909.A7F061F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > From: "Rafael J. Wysocki" >=20 > The parent state update in acpi_device_get_power(), that occurs when the > child device turns out to be in D0 and the parent's power state is still > unknown, is highly questionable because it may cause the reference > counters of the power resources used by the parent in D0 (if any) to > underflow when the parent goes into a low-power state later. Moreover, > there is no reason to do it on reads from the real_power_state sysfs > attribute of the child. >=20 > That check had been added by commit 8f7412a792bc ("ACPI / PM: Infer > parent power state from child if unknown, v2") before starting to > handle the "missing _PSC and no power resources" case directly in > acpi_bus_init_power(), as of commit b3785492268f ("ACPI / PM: Do not > power manage devices in unknown initial states"). It is not necessary > any more and commit b3785492268f should have removed it. >=20 > Drop it now. >=20 > Fixes: b3785492268f ("ACPI / PM: Do not power manage devices in unknown i= nitial states") > Signed-off-by: Rafael J. Wysocki Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/6044499.DvuYhMxLoT@= rafael.j.wysocki?part=3D1