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-rw-r--r--drivers/scsi/sata_svw.c43
1 files changed, 24 insertions, 19 deletions
diff --git a/drivers/scsi/sata_svw.c b/drivers/scsi/sata_svw.c
index 858e07185dbd..19d3bb3b0fb6 100644
--- a/drivers/scsi/sata_svw.c
+++ b/drivers/scsi/sata_svw.c
@@ -13,21 +13,26 @@
13 * This driver probably works with non-Apple versions of the 13 * This driver probably works with non-Apple versions of the
14 * Broadcom chipset... 14 * Broadcom chipset...
15 * 15 *
16 * The contents of this file are subject to the Open
17 * Software License version 1.1 that can be found at
18 * http://www.opensource.org/licenses/osl-1.1.txt and is included herein
19 * by reference.
20 * 16 *
21 * Alternatively, the contents of this file may be used under the terms 17 * This program is free software; you can redistribute it and/or modify
22 * of the GNU General Public License version 2 (the "GPL") as distributed 18 * it under the terms of the GNU General Public License as published by
23 * in the kernel source COPYING file, in which case the provisions of 19 * the Free Software Foundation; either version 2, or (at your option)
24 * the GPL are applicable instead of the above. If you wish to allow 20 * any later version.
25 * the use of your version of this file only under the terms of the 21 *
26 * GPL and not to allow others to use your version of this file under 22 * This program is distributed in the hope that it will be useful,
27 * the OSL, indicate your decision by deleting the provisions above and 23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
28 * replace them with the notice and other provisions required by the GPL. 24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
29 * If you do not delete the provisions above, a recipient may use your 25 * GNU General Public License for more details.
30 * version of this file under either the OSL or the GPL. 26 *
27 * You should have received a copy of the GNU General Public License
28 * along with this program; see the file COPYING. If not, write to
29 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
30 *
31 *
32 * libata documentation is available via 'make {ps|pdf}docs',
33 * as Documentation/DocBook/libata.*
34 *
35 * Hardware documentation available under NDA.
31 * 36 *
32 */ 37 */
33 38
@@ -195,18 +200,18 @@ static void k2_bmdma_start_mmio (struct ata_queued_cmd *qc)
195 /* start host DMA transaction */ 200 /* start host DMA transaction */
196 dmactl = readb(mmio + ATA_DMA_CMD); 201 dmactl = readb(mmio + ATA_DMA_CMD);
197 writeb(dmactl | ATA_DMA_START, mmio + ATA_DMA_CMD); 202 writeb(dmactl | ATA_DMA_START, mmio + ATA_DMA_CMD);
198 /* There is a race condition in certain SATA controllers that can 203 /* There is a race condition in certain SATA controllers that can
199 be seen when the r/w command is given to the controller before the 204 be seen when the r/w command is given to the controller before the
200 host DMA is started. On a Read command, the controller would initiate 205 host DMA is started. On a Read command, the controller would initiate
201 the command to the drive even before it sees the DMA start. When there 206 the command to the drive even before it sees the DMA start. When there
202 are very fast drives connected to the controller, or when the data request 207 are very fast drives connected to the controller, or when the data request
203 hits in the drive cache, there is the possibility that the drive returns a part 208 hits in the drive cache, there is the possibility that the drive returns a part
204 or all of the requested data to the controller before the DMA start is issued. 209 or all of the requested data to the controller before the DMA start is issued.
205 In this case, the controller would become confused as to what to do with the data. 210 In this case, the controller would become confused as to what to do with the data.
206 In the worst case when all the data is returned back to the controller, the 211 In the worst case when all the data is returned back to the controller, the
207 controller could hang. In other cases it could return partial data returning 212 controller could hang. In other cases it could return partial data returning
208 in data corruption. This problem has been seen in PPC systems and can also appear 213 in data corruption. This problem has been seen in PPC systems and can also appear
209 on an system with very fast disks, where the SATA controller is sitting behind a 214 on an system with very fast disks, where the SATA controller is sitting behind a
210 number of bridges, and hence there is significant latency between the r/w command 215 number of bridges, and hence there is significant latency between the r/w command
211 and the start command. */ 216 and the start command. */
212 /* issue r/w command if the access is to ATA*/ 217 /* issue r/w command if the access is to ATA*/
@@ -214,7 +219,7 @@ static void k2_bmdma_start_mmio (struct ata_queued_cmd *qc)
214 ap->ops->exec_command(ap, &qc->tf); 219 ap->ops->exec_command(ap, &qc->tf);
215} 220}
216 221
217 222
218static u8 k2_stat_check_status(struct ata_port *ap) 223static u8 k2_stat_check_status(struct ata_port *ap)
219{ 224{
220 return readl((void *) ap->ioaddr.status_addr); 225 return readl((void *) ap->ioaddr.status_addr);