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 4C8D52374C; Tue, 18 Jun 2024 15:28:38 +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=1718724518; cv=none; b=Cs7Bi/s2yBRCCCGAqzTZddADe/L4LaEbbS3NXwwV2ujQXbXZJtPNmyx15kgrxKlvdpZpqC2L9E/T1K53zY2qqsgRSjKdElkfUnsF2t4mcfYM51d49NCt+JpVkVxUwzt7d3FTUeYxj/KK4HmXEthOJuPO1KEKdo0yKGFZO4Plooo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718724518; c=relaxed/simple; bh=du4uYRUyBre9GJwIUBABF9CFXaOVppE+rA63dxQj/GA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=p3eZxxrN/mFHgx8yPdEYLqEAfABblr2rw8+S1+tgAR0hEs9Ik9268nsZa1+m+yE8l9f/OOQ2W5M7xfHTRwjTTi1DEBcepYakVCZNCWrQLOrDZRHK9N6PpKbtVJ6NE5mQVNdYqQ51v3wEfJ8aEtrVy4+11N3tJhcqQMSwawBys80= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GuXU8WD4; 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="GuXU8WD4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 549BFC4AF1D; Tue, 18 Jun 2024 15:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718724517; bh=du4uYRUyBre9GJwIUBABF9CFXaOVppE+rA63dxQj/GA=; h=From:To:Cc:Subject:Date:From; b=GuXU8WD4ncpWVPQNdyAljUrihqX9fP+D4i3pcFGb3IKduXOYnEXWHgzeokqQeHHpn N1Uiv3c+Ltk4SzI65+XCFLqdBY1Sd62A1k3mAb7Fv8A7wsgcg721ss2s9b1zjXsqeH EJQt/9W3DJdcFffBlbyW8QqZ2dXFAPXTP4YbCVU4iV50oxnepN8uTvucKgRS1y4O6n Df+qfUKZrblXwfoGPw44hdOgiqhpwhuuDszIHi4BiGqXSrty1BlNG/CMk4CiFN9LHX PYV/nxLa0muWF6ZhpoM3QMAqZ8ZrO/TFBaKdUCc5N1vZRQE5RmCOt5skfHHHoOy4S5 3bWFGzkyb+xnQ== From: Niklas Cassel To: Damien Le Moal , Niklas Cassel , Mario Limonciello , Mika Westerberg , Jian-Hong Pan Cc: stable@vger.kernel.org, linux-ide@vger.kernel.org Subject: [PATCH v2] ata: ahci: Do not enable LPM if no LPM states are supported by the HBA Date: Tue, 18 Jun 2024 17:28:29 +0200 Message-ID: <20240618152828.2686771-2-cassel@kernel.org> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-ide@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2384; i=cassel@kernel.org; h=from:subject; bh=du4uYRUyBre9GJwIUBABF9CFXaOVppE+rA63dxQj/GA=; b=owGbwMvMwCV2MsVw8cxjvkWMp9WSGNIKl8+Z4JxYGP/5UPfB5+eeO3zind8bXdlSJGa5ckLtt ENv/jzy7ShlYRDjYpAVU2Tx/eGyv7jbfcpxxTs2MHNYmUCGMHBxCsBE1v9j+Cuc5RB90GpvgtTx 5+FX26d8e6XNPyHsTnTmzcYFLhN/vV/G8D9q2+smT8F75TN0rui3ndi+y7b495wbAfdSburd7tx 4k4MJAA== X-Developer-Key: i=cassel@kernel.org; a=openpgp; fpr=5ADE635C0E631CBBD5BE065A352FE6582ED9B5DA Content-Transfer-Encoding: 8bit LPM consists of HIPM (host initiated power management) and DIPM (device initiated power management). ata_eh_set_lpm() will only enable HIPM if both the HBA and the device supports it. However, DIPM will be enabled as long as the device supports it. The HBA will later reject the device's request to enter a power state that it does not support (Slumber/Partial/DevSleep) (DevSleep is never initiated by the device). For a HBA that doesn't support any LPM states, simply don't set a LPM policy such that all the HIPM/DIPM probing/enabling will be skipped. Not enabling HIPM or DIPM in the first place is safer than relying on the device following the AHCI specification and respecting the NAK. (There are comments in the code that some devices misbehave when receiving a NAK.) Performing this check in ahci_update_initial_lpm_policy() also has the advantage that a HBA that doesn't support any LPM states will take the exact same code paths as a port that is external/hot plug capable. Side note: the port in ata_port_dbg() has not been given a unique id yet, but this is not overly important as the debug print is disabled unless explicitly enabled using dynamic debug. A follow-up series will make sure that the unique id assignment will be done earlier. For now, the important thing is that the function returns before setting the LPM policy. Fixes: 7627a0edef54 ("ata: ahci: Drop low power policy board type") Cc: stable@vger.kernel.org Signed-off-by: Niklas Cassel --- Changes since v1: Add debug print as suggested by Mika. drivers/ata/ahci.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 07d66d2c5f0d..5eb38fbbbecd 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1735,6 +1735,14 @@ static void ahci_update_initial_lpm_policy(struct ata_port *ap) if (ap->pflags & ATA_PFLAG_EXTERNAL) return; + /* If no LPM states are supported by the HBA, do not bother with LPM */ + if ((ap->host->flags & ATA_HOST_NO_PART) && + (ap->host->flags & ATA_HOST_NO_SSC) && + (ap->host->flags & ATA_HOST_NO_DEVSLP)) { + ata_port_dbg(ap, "no LPM states supported, not enabling LPM\n"); + return; + } + /* user modified policy via module param */ if (mobile_lpm_policy != -1) { policy = mobile_lpm_policy; -- 2.45.2