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 954F93A1E71 for ; Wed, 14 Jan 2026 16:25:11 +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=1768407911; cv=none; b=bbSq9WbQw1ZyjXYiJru+lAK4EWssrwvvhoY9voWsNKW5LiPPWbq/VeXJHcBxSRs4lhtJcanvrjd8hHd6JMDovgTtxSF5c45fAWnZQAayyqVI/YwdQ6dLKcrFxuoaf3yGN0QMW9y73VpXGG+i7UORHH2Rb/qavvEaWrovJN1ngFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768407911; c=relaxed/simple; bh=7axy5Ujtl+85/UQgkxRbuYqk8MNK91eI/THV8lmVkk8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KtZvcT1+kpTsHKOpeyAQF7qDjQiWDljMtbni4gi4rzP36QbiA8doGv+jxQ8gv+9qXq/7PxnEx0h+bJvY/o2bvFxUYfoYXcpzbe342gz+SfZgua/dlCK1GpTY8/WR2i0HLkfSewfeBXbOOF0APbcmtyq+QCu00g8mfCMd51M0+oE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JDugAJTa; 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="JDugAJTa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D01A4C16AAE; Wed, 14 Jan 2026 16:25:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768407911; bh=7axy5Ujtl+85/UQgkxRbuYqk8MNK91eI/THV8lmVkk8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JDugAJTaZTzLAbYIzCe3EQrZe2Wb/SXT8nkJAI5OV+xj1Lpvp0JFk7hJdqRiPeem9 8q0om+hUxE1+gNclr3fbsDxGiMe9V+/i86uJ8APJlqSMWSC1IoYsKzSPoh3bI2aazC qJy+YiEJCWcglueC1VG4gMxwF+dELTJ2lEITxqr1pdeMsBbyZd1nG5sX2v/AwrEnjg CsReAyUluWH6txoAKY33HMoVgZftRbbr4CyRj8JXw/qR1cx6LQb7rfdTVyCW1waxXh U+7BWMFRxpasyuklhzYN1wiGnFciuHyuymsjXo5xRh7JVe44KT259l0H3w2yN1DRUY 7+sqPGZQ1ur1w== Date: Wed, 14 Jan 2026 17:25:05 +0100 From: Niklas Cassel To: Wolf , dlemoal@kernel.org Cc: 1120831@bugs.debian.org, linux-ide@vger.kernel.org Subject: Re: [regression] failed command: READ FPDMA QUEUED after boot for INTEL SSDSC2KG480G8, XCV10120 after 9b8b84879d4a ("block: Increase BLK_DEF_MAX_SECTORS_CAP") Message-ID: References: <176839089913.2398366.61500945766820256@eldamar.lan> Precedence: bulk X-Mailing-List: linux-ide@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hello Wolf, On Wed, Jan 14, 2026 at 03:11:50PM +0000, Wolf wrote: > Here is find-max-sectors.sh output: > > Drive model: > INTEL SSDSC2KG480G8 > > Drive firmware: > XCV10120 > > SATA / AHCI controller: > 00:17.0 SATA controller [0106]: Intel Corporation Cannon Lake Mobile PCH SATA AHCI Controller [8086:a353] (rev 10) > > Drive values before running the test: > /sys/block/sda/queue/max_hw_sectors_kb:32767 > /sys/block/sda/queue/max_sectors_kb:1280 > /sys/block/sda/queue/read_ahead_kb:128 > > Running test with max_sectors 128 KiB > Test: PASS > > Running test with max_sectors 1024 KiB > Test: PASS > > Running test with max_sectors 2048 KiB > Test: PASS > > Running test with max_sectors 3072 KiB > Test: PASS > > Running test with max_sectors 4095 KiB > Test: PASS > > Running test with max_sectors 4096 KiB > Test: PASS It is quite unexpected that 4096 KiB passes. find-max-sectors.sh performs reads. The commands that timed out according to dmesg shared were also reads: Dec 10 18:58:49 kernel: ata1.00: failed command: READ FPDMA QUEUED Dec 10 18:58:49 kernel: ata1.00: cmd 60/00:18:50:4a:4c/20:00:0c:00:00/40 tag 3 ncq dma 4194304 in res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) And also of size 4194304 == 4096 KiB. The script has been able to detect different limits for other "broken" drives, and was used to get the quirk value for e.g. commit 2e9832713631 ("ata: libata-core: Quirk DELLBOSS VD max_sectors"), so I wonder why it is not workin here (why 4 MiB reads passes). Damien, ideas? Kind regards, Niklas