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 01431494A00 for ; Wed, 13 May 2026 15:14:12 +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=1778685253; cv=none; b=aHViWVeERm4g2KYU4nIkEGBX9ruwZAe1gkylYDo6tpA8jv0TxNKql+uTBgehXPpBXzte9EAJpiOiuXXSSo4pwHQXST6tl8P6NOB3ofo9Jh4TVKjfQtLmqImcXyjASbmPE74PzxyNz3uQNqg6s56aj4lEmPLHH98nN6GT2JXhamI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778685253; c=relaxed/simple; bh=QL1hgyowVfja/vcJIALXSKCDzjwmNt42m3BowKG8WeQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t3Bh1JliCfNHSXjeS8v3DPiesUWIT35Y+iK8h/RMitngb6R+GBbmKjEFhTFPNeG++RrYb/Dxx9wtSvnxB3+2j4K1ihGrVdup56EmD7/FnozVbxhECGZ9vBxdB/TnAW6um0W5Cu8ZGTV+MtuXBWBARk2Yt7KTI52mDcnqOJjhB0A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AaJw5sJV; 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="AaJw5sJV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3025AC19425; Wed, 13 May 2026 15:14:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778685252; bh=QL1hgyowVfja/vcJIALXSKCDzjwmNt42m3BowKG8WeQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AaJw5sJVaOCRaU2hB4vvcQajcqQjX7ruecf55JaFFubL0BZnwjFDDM8GOB2+2nAVt FJTPB83Qaw8AniTQKZJvBqbCFhEaSi7xjyYZXtQcaMhqfQhJJwYdXcml+Z3uQrFru3 hGUs3ZQcPc2By2WRNj6sd/hgXoNiKp+4CQlRMcEdsgcbM+Opee6V5F9nmVBSYVd2eh GPrCSfkKeXyQU/ju9+HRqZDUYjHLYb9S1TunPqSotTh6plMP7dNRSejVaMtjJmGKMU 7JhpbrpbdrLN+/GZNr2fRDgLw7gJ1pOyfMhGQmDZG1qfBPrl7pQhLoxhdjT7qxOYjh xul/W9GXQaFuQ== From: Niklas Cassel To: Tommy Kelly , Damien Le Moal , Niklas Cassel , John Garry , "Martin K. Petersen" Cc: linux-ide@vger.kernel.org Subject: [PATCH v4 2/4] ata: libata-scsi: do not use the deferred QC feature for ATA_DEFER_PORT Date: Wed, 13 May 2026 17:14:01 +0200 Message-ID: <20260513151359.1075403-8-cassel@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260513151359.1075403-6-cassel@kernel.org> References: <20260513151359.1075403-6-cassel@kernel.org> 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=1567; i=cassel@kernel.org; h=from:subject; bh=QL1hgyowVfja/vcJIALXSKCDzjwmNt42m3BowKG8WeQ=; b=owGbwMvMwCV2MsVw8cxjvkWMp9WSGLJYppq7PlbM0Fq6gOfF3uPrcoJeVP3jqLzVU8r6VXweh /fNErN9HaUsDGJcDLJiiiy+P1z2F3e7TzmueMcGZg4rE8gQBi5OAZjIX0FGhj3PuXafd3/++J/p 9/JeofMrWXx8lOY67ePYbGXS2th2ZRsjw4OwaRWZsplp1o+YJA53vDTPWZaQOOtMwix2J+0FiyV 5OAE= X-Developer-Key: i=cassel@kernel.org; a=openpgp; fpr=5ADE635C0E631CBBD5BE065A352FE6582ED9B5DA Content-Transfer-Encoding: 8bit The deferred QC feature was meant to handle mixed NCQ and non-NCQ commands, i.e. for return value ATA_DEFER_LINK. ATA_DEFER_PORT is returned by PATA drivers, but also certain SATA drivers like sata_mv and sata_sil24 that uses ap->excl_link to workaround hardware bugs in these HBAs. Regardless of the reason, using the deferred QC feature for ATA_DEFER_PORT is always wrong, and will break the ap->excl_link usage of the SATA drivers that rely on that feature. Modify ata_scsi_qc_issue() to only use the deferred QC feature when mixing NCQ and non-NCQ commands, i.e. ATA_DEFER_LINK. Fixes: 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation") Signed-off-by: Niklas Cassel --- drivers/ata/libata-scsi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index b9064dd4390c..22642a0e6b84 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -1789,11 +1789,11 @@ static int ata_scsi_qc_issue(struct ata_port *ap, struct ata_queued_cmd *qc) goto defer_qc; case ATA_DEFER_PORT: ret = SCSI_MLQUEUE_HOST_BUSY; - goto defer_qc; + goto free_qc; default: WARN_ON_ONCE(1); ret = SCSI_MLQUEUE_HOST_BUSY; - goto defer_qc; + goto free_qc; } issue_qc: @@ -1813,6 +1813,7 @@ static int ata_scsi_qc_issue(struct ata_port *ap, struct ata_queued_cmd *qc) return 0; } +free_qc: /* Force a requeue of the command to defer its execution. */ ata_qc_free(qc); -- 2.54.0