[U-Boot] [PATCH 19/20] ahci: Expand HDD Logical Block addressability up to 32 bits

[Simon Glass]

From: Walter Murphy <wmurphy at google.com>

Currently, this driver uses a 28bit interface to AHCI, this
limits the number of blocks addressable to 2^28, or the max
disk size to 512(2^28) or about 137GB. This change allows
supporting drives up to about 2TB.

Testing this is a bit difficult. There is test code that
can be inserted into U-Boot that will write test patterns
into certain unused blocks. These patterns can be manually
checked using 'dd' after boot. Another way is to confirm the
original error that exposed this bug is fixed. IOW: see if
AU (Auto Update) will now work on the drive. Also, check
that there are no warning messages from the 'cgpt' utility.

Signed-off-by: Walter Murphy <wmurphy at chromium.org>
Signed-off-by: Simon Glass <sjg at chromium.org>
---
 drivers/block/ahci.c |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/block/ahci.c b/drivers/block/ahci.c
index 963efec..8c785ae 100644
--- a/drivers/block/ahci.c
+++ b/drivers/block/ahci.c
@@ -707,7 +707,7 @@ static int ata_scsiop_read_write(ccb *pccb, u8 is_write)
 	fis[0] = 0x27;		 /* Host to device FIS. */
 	fis[1] = 1 << 7;	 /* Command FIS. */
 	/* Command byte (read/write). */
-	fis[2] = is_write ? ATA_CMD_WR_DMA : ATA_CMD_RD_DMA;
+	fis[2] = is_write ? ATA_CMD_WRITE_EXT : ATA_CMD_READ_EXT;
 
 	while (blocks) {
 		u16 now_blocks; /* number of blocks per iteration */
@@ -721,11 +721,15 @@ static int ata_scsiop_read_write(ccb *pccb, u8 is_write)
 			return -EIO;
 		}
 
-		/* LBA address, only support LBA28 in this driver */
+		/* LBA48 SATA command but only use 32bit address range within
+		 * that. The next smaller command range (28bit) is too small.
+		 */
 		fis[4] = (lba >> 0) & 0xff;
 		fis[5] = (lba >> 8) & 0xff;
 		fis[6] = (lba >> 16) & 0xff;
-		fis[7] = ((lba >> 24) & 0xf) | 0xe0;
+		fis[7] = 1 << 6; /* device reg: set LBA mode */
+		fis[8] = ((lba >> 24) & 0xff);
+		fis[3] = 0xe0; /* features */
 
 		/* Block (sector) count */
 		fis[12] = (now_blocks >> 0) & 0xff;
@@ -963,7 +967,7 @@ static int ata_io_flush(u8 port)
 	memset(fis, 0, 20);
 	fis[0] = 0x27;		 /* Host to device FIS. */
 	fis[1] = 1 << 7;	 /* Command FIS. */
-	fis[2] = ATA_CMD_FLUSH;
+	fis[2] = ATA_CMD_FLUSH_EXT;
 
 	memcpy((unsigned char *)pp->cmd_tbl, fis, 20);
 	ahci_fill_cmd_slot(pp, cmd_fis_len);
-- 
1.7.7.3