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 A80691A2C0B; Thu, 15 Oct 2026 05:37:48 +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=1792042669; cv=none; b=acqyWRD+8RamYmRdb1KkLgBtNUAVhLJsSCmoI/BKC9Jua9PfG21q2aHb2yS87zYhQrxmNcT1Sm+3UrxHoq4sSSSu9Z0TymT5krkSJmoDzX7F6w6cRDxDpCmVbocHghG+fS/ceGGsQyLfAtEfcToyWNm87An+/55ULO9inySM3zA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792042669; c=relaxed/simple; bh=eRPofMYnBCfCl542RM3WrRFosCu/RBhbPhw4M22mzUE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qweq7lxCwdX6iyTzIunEKPcXtnffD1BRezw+b/y3nM4AOKApuc03OS8QpqfkmpGmxioiY4C56CNzfeOyRhUShAPIb/6W22mrbiDsKuzjUEoCunKnqaQ+dN65DbZUIdZdtQaYGT1N7B1C5dvWUCNlHxgc+aT0q57pei/133qRej8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QiRcjtXI; 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="QiRcjtXI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CF5A1F000C4; Thu, 15 Oct 2026 05:37:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792042668; bh=zYg5CWGxSdeKDaRo/A92SDbKDroOZH6PvO8iZ+HbgnE=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=QiRcjtXIJJ5isGPGSe4B+BDrnpUv4N5ymd1+fa/t3BDzibiUB2MR9tcsG+VEDcIFC MOC+z80peHijYscreZj2JsazByj17f8+XTq8thETxT20inFsHjdvD60RQjVejyyTio ENyr2fNhspoIlnCeVSk4DDuDE5Epuu1oK7UY4tuBmWpWNCzvde6uBiB/h2N/oyL4gA n81iACpYmocayG4zGkp1Ujd54qd8MsMhR1Y/Nxy4yKAG3AhU4hLKBoJPLKS6bmJcys 0jAoSU+Y2oe8QUueeFmIgxFkrQ/H0i44RHsR8u86FrUc6MiIN5v1LxnUKSbW1SJwQT epTSizKeF34Jg== Message-ID: Date: Thu, 15 Oct 2026 07:37:45 +0200 Precedence: bulk X-Mailing-List: linux-ide@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4] ata: libahci: re-enable FBS after error handling on a port multiplier To: Kyrylo Biryuk , linux-ide@vger.kernel.org Cc: cassel@kernel.org, linux-kernel@vger.kernel.org References: <20261012103917.389-1-illofspeed@gmail.com> From: Damien Le Moal Content-Language: en-US Organization: Western Digital Research In-Reply-To: <20261012103917.389-1-illofspeed@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2026/10/12 12:39, Kyrylo Biryuk wrote: > ahci_do_softreset() disables FBS before resetting a device behind a port > multiplier, as required by AHCI 1.2 section 9.3.9, and re-enables it only > when that softreset succeeds. If it fails, for example because a > hot-plugged drive is still spinning up ("softreset failed (device not > ready)"), EH escalates to a hardreset of the PMP link, and nothing turns > FBS back on: only ahci_pmp_attach() does, which runs at the next boot. > The port keeps working with command-based switching until then. > > Seen on a Marvell 88SE9235 (1b4b:9235) with Marvell 88SM9705 port > multipliers (1b4b:9705, in a Synology DX1222 expansion unit): after > hot-plugging a drive, the kernel logged "FBS is disabled" followed by > "softreset failed (device not ready)" and a PMP hardreset, and never > "FBS is enabled" again (twice, on two different ports). > > At the end of ahci_error_handler(), re-enable FBS if a PMP is still > attached and FBS is supported but disabled. > > Fixes: 89dafa20f3da ("ahci: disabled FBS prior to issuing software reset") > Assisted-by: LLM > Signed-off-by: Kyrylo Biryuk Looks good. Reviewed-by: Damien Le Moal -- Damien Le Moal Western Digital Research