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From:   John Garry <john.garry@huawei.com>
To:     <damien.lemoal@opensource.wdc.com>, <joro@8bytes.org>,
        <will@kernel.org>, <jejb@linux.ibm.com>,
        <martin.petersen@oracle.com>, <hch@lst.de>,
        <m.szyprowski@samsung.com>, <robin.murphy@arm.com>
CC:     <linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-ide@vger.kernel.org>, <iommu@lists.linux-foundation.org>,
        <iommu@lists.linux.dev>, <linux-scsi@vger.kernel.org>,
        <linuxarm@huawei.com>, John Garry <john.garry@huawei.com>
Subject: [PATCH v4 5/5] libata-scsi: Cap ata_device->max_sectors according to shost->max_sectors
Date:   Mon, 27 Jun 2022 23:25:21 +0800
Message-ID: <1656343521-62897-6-git-send-email-john.garry@huawei.com>
In-Reply-To: <1656343521-62897-1-git-send-email-john.garry@huawei.com>
References: <1656343521-62897-1-git-send-email-john.garry@huawei.com>
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ATA devices (struct ata_device) have a max_sectors field which is
configured internally in libata. This is then used to (re)configure the
associated sdev request queue max_sectors value from how it is earlier set
in __scsi_init_queue(). In __scsi_init_queue() the max_sectors value is set
according to shost limits, which includes host DMA mapping limits.

Cap the ata_device max_sectors according to shost->max_sectors to respect
this shost limit.

Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
---
 drivers/ata/libata-scsi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 86dbb1cdfabd..24a43d540d9f 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1060,6 +1060,7 @@ int ata_scsi_dev_config(struct scsi_device *sdev, struct ata_device *dev)
 		dev->flags |= ATA_DFLAG_NO_UNLOAD;
 
 	/* configure max sectors */
+	dev->max_sectors = min(dev->max_sectors, sdev->host->max_sectors);
 	blk_queue_max_hw_sectors(q, dev->max_sectors);
 
 	if (dev->class == ATA_DEV_ATAPI) {
-- 
2.35.3