--- drivers/ata/libata-scsi.c

+++ drivers/ata/libata-scsi.c

@@ -1099,13 +1099,13 @@ static int ata_scsi_dev_config(struct sc

/* configure max sectors */

blk_queue_max_sectors(sdev->request_queue, dev->max_sectors);

+ sdev->sector_size = ATA_SECT_SIZE;

+

if (dev->class == ATA_DEV_ATAPI) {

struct request_queue *q = sdev->request_queue;

void *buf;

- /* set the min alignment and padding */

- blk_queue_update_dma_alignment(sdev->request_queue,

- ATA_DMA_PAD_SZ - 1);

+ /* set DMA padding */

blk_queue_update_dma_pad(sdev->request_queue,

ATA_DMA_PAD_SZ - 1);

@@ -1119,12 +1119,24 @@ static int ata_scsi_dev_config(struct sc

blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN);

} else {

- /* ATA devices must be sector aligned */

- blk_queue_update_dma_alignment(sdev->request_queue,

- ATA_SECT_SIZE - 1);

sdev->manage_start_stop = 1;

}

+ /*

+ * ata_pio_sectors() expects buffer for each sector to not cross

+ * page boundary. Enforce it by requiring buffers to be sector

+ * aligned, which works iff sector_size is not larger than

+ * PAGE_SIZE. ATAPI devices also need the alignment as

+ * IDENTIFY_PACKET is executed as ATA_PROT_PIO.

+ */

+ if (sdev->sector_size > PAGE_SIZE)

+ ata_dev_printk(dev, KERN_WARNING,

+ "sector_size=%u > PAGE_SIZE, PIO may malfunction\n",

+ sdev->sector_size);

+

+ blk_queue_update_dma_alignment(sdev->request_queue,

+ sdev->sector_size - 1);

+

if (dev->flags & ATA_DFLAG_AN)

set_bit(SDEV_EVT_MEDIA_CHANGE, sdev->supported_events);