From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpo63.interia.pl (smtpo63.interia.pl [217.74.67.63]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 914062BE7C3 for ; Sun, 14 Dec 2025 15:28:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.74.67.63 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765726101; cv=none; b=a+mS3vBNG/gpoRopp5kKQ3Q0k0DCswgNbmXsjGlufrO9MzeegtBbdZrWianNzO65SD9gw4DOSVzkQR1qt6IMzu5WJ3+R/CNFktTlWnhg+o9lxe058n8MGrV0Bc39Q3le+T7uXw7GGAqzbe2lNpVqAn8XxoYVX43d4YIN7oCbDis= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765726101; c=relaxed/simple; bh=r9jl588+AB2bhKoIUevD21DpcMayOaINrcKPtcIZ7wg=; h=Message-ID:Date:MIME-Version:To:Cc:From:Subject:Content-Type; b=qof50JTxUOunLef/2HFpGFAT/6YCUvujqIe2/CPzlZCLKOe+7xhiuAalq2cHUYRRxKUxxd4s6G8hu30mY6seVs3M+lkgnLbMFRT1JHMwegkBZjAn7utgLnCNlv3YBOszo6UojnKxVrX1oYf5MwJLTfz+uuHuEGxZjZrXuFVLxhY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=interia.pl; spf=pass smtp.mailfrom=interia.pl; dkim=pass (1024-bit key) header.d=interia.pl header.i=@interia.pl header.b=BQheKZaj; arc=none smtp.client-ip=217.74.67.63 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=interia.pl Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=interia.pl Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=interia.pl header.i=@interia.pl header.b="BQheKZaj" Received: from [10.10.11.15] (host-46-174-211-152.podkarpacki.net [46.174.211.152]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by poczta.interia.pl (INTERIA.PL) with ESMTPSA; Sun, 14 Dec 2025 16:26:56 +0100 (CET) Message-ID: <635cb04f-eda3-49ec-b8bc-62f4e8c7926f@interia.pl> Date: Sun, 14 Dec 2025 16:26:55 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: pl To: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Cc: damien.lemoal@opensource.wdc.com From: Bernard Drozd Subject: [REGRESSION] libata: SATA LPM forcibly disabled on Intel Jasper Lake since Linux 6.13 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-IPL-Priority-Group: 0-0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=interia.pl; s=dk; t=1765726017; bh=uvzF3WLusyfFzertzUam0GzBAhZQPkSgxjsiOgCrrk0=; h=Message-ID:Date:MIME-Version:To:From:Subject:Content-Type; b=BQheKZaj4i8JlHVY/tgNM1xQ5pjU3lsMf6jk9OiH1gt4Jy+AEvNWalle5qbtOXBb/ 2U9wDBckBMoXUeop26bZ+I52VKaAaU+zmFTVU3d+7cA7Gra4a92fBdTqRru4Eyp+C9 sh6YwWE15Se80IleeEueOM8FUsc+6HqdAnWLegLE= Hello, I am reporting a power-management regression in libata affecting Intel Jasper Lake platforms, introduced after Linux 6.12. Hardware: - CPU / SoC: Intel Jasper Lake (Elkhart Lake class) - SATA controller: Intel Jasper Lake SATA AHCI Controller (PCI ID 8086:4d03) - Drives tested: SATA SSD + SATA HDD (multiple vendors) - Distribution: Debian 13 (Trixie) - Kernel versions tested:   - 6.12.x  → OK   - 6.17.x  → REGRESSION Problem description: Since kernel >= 6.13, SATA Link Power Management (LPM) is forcibly disabled. The sysfs interface still exists but only reports:   /sys/class/scsi_host/host*/link_power_management_policy = max_performance Attempts to change it fail silently or are ignored: echo 'med_power_with_dipm' > '/sys/class/scsi_host/host0/link_power_management_policy' echo 'med_power_with_dipm' > '/sys/class/scsi_host/host1/link_power_management_policy' This worked correctly on kernel 6.12.x and earlier. Observed effects: - SATA devices never enter partial/slumber - CPU package C-states are limited (system mostly stuck in PC2 (before the change i had C10)) - Idle power consumption increases by ~5 W - powertop shows SATA LPM tunables as permanently "Bad" Relevant dmesg output (6.17.x):   ata1: SATA link power management disabled due to platform quirk   ata2: SATA link power management disabled due to platform quirk This appears to be caused by the libata change disabling LPM on Intel platforms without a per-platform whitelist. Jasper Lake does not exhibit instability with LPM enabled and worked reliably on previous kernels. Expectation: - Either re-enable LPM for Intel Jasper Lake - Or provide a kernel parameter to override the forced LPM disable   (e.g. libata.allow_lpm=1) This regression significantly impacts low-power systems and fanless mini-PCs based on Jasper Lake. Please let me know if additional logs or testing are needed. Best regards, bern