1 files changed, 27 insertions, 25 deletions

diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index 1eda11abeb1e..2b889d91e673 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -51,6 +51,7 @@
  * Grep for inline FIXME comments below.
  */
 
+#include <linux/blkdev.h>
 #include <linux/compiler.h>
 #include <linux/delay.h>
 #include <linux/device.h>
@@ -127,17 +128,21 @@ MODULE_PARM_DESC(serialize_io, "Serialize requests coming from SCSI drivers "
                  "(default = Y, faster but buggy = N)");
 
 /*
- * Bump up max_sectors if you'd like to support very large sized
- * transfers. Please note that some older sbp2 bridge chips are broken for
- * transfers greater or equal to 128KB.  Default is a value of 255
- * sectors, or just under 128KB (at 512 byte sector size). I can note that
- * the Oxsemi sbp2 chipsets have no problems supporting very large
- * transfer sizes.
+ * Adjust max_sectors if you'd like to influence how many sectors each SCSI
+ * command can transfer at most. Please note that some older SBP-2 bridge
+ * chips are broken for transfers greater or equal to 128KB, therefore
+ * max_sectors used to be a safe 255 sectors for many years. We now have a
+ * default of 0 here which means that we let the SCSI stack choose a limit.
+ *
+ * The SBP2_WORKAROUND_128K_MAX_TRANS flag, if set either in the workarounds
+ * module parameter or in the sbp2_workarounds_table[], will override the
+ * value of max_sectors. We should use sbp2_workarounds_table[] to cover any
+ * bridge chip which becomes known to need the 255 sectors limit.
  */
-static int sbp2_max_sectors = SBP2_MAX_SECTORS;
+static int sbp2_max_sectors;
 module_param_named(max_sectors, sbp2_max_sectors, int, 0444);
 MODULE_PARM_DESC(max_sectors, "Change max sectors per I/O supported "
-                 "(default = " __stringify(SBP2_MAX_SECTORS) ")");
+                 "(default = 0 = use SCSI stack's default)");
 
 /*
  * Exclusive login to sbp2 device? In most cases, the sbp2 driver should
@@ -1451,7 +1456,7 @@ static void sbp2_prep_command_orb_sg(struct sbp2_command_orb *orb,
                                      struct sbp2_fwhost_info *hi,
                                      struct sbp2_command_info *cmd,
                                      unsigned int scsi_use_sg,
-                                     struct scatterlist *sgpnt,
+                                     struct scatterlist *sg,
                                      u32 orb_direction,
                                      enum dma_data_direction dma_dir)
 {
@@ -1461,12 +1466,12 @@ static void sbp2_prep_command_orb_sg(struct sbp2_command_orb *orb,
 
         /* special case if only one element (and less than 64KB in size) */
         if ((scsi_use_sg == 1) &&
-            (sgpnt[0].length <= SBP2_MAX_SG_ELEMENT_LENGTH)) {
+            (sg_dma_len(sg) <= SBP2_MAX_SG_ELEMENT_LENGTH)) {
 
-                cmd->dma_size = sgpnt[0].length;
+                cmd->dma_size = sg_dma_len(sg);
                 cmd->dma_type = CMD_DMA_PAGE;
                 cmd->cmd_dma = dma_map_page(hi->host->device.parent,
-                                            sg_page(&sgpnt[0]), sgpnt[0].offset,
+                                            sg_page(sg), sg->offset,
                                             cmd->dma_size, cmd->dma_dir);
 
                 orb->data_descriptor_lo = cmd->cmd_dma;
@@ -1477,11 +1482,11 @@ static void sbp2_prep_command_orb_sg(struct sbp2_command_orb *orb,
                                                 &cmd->scatter_gather_element[0];
                 u32 sg_count, sg_len;
                 dma_addr_t sg_addr;
-                int i, count = dma_map_sg(hi->host->device.parent, sgpnt,
+                int i, count = dma_map_sg(hi->host->device.parent, sg,
                                           scsi_use_sg, dma_dir);
 
                 cmd->dma_size = scsi_use_sg;
-                cmd->sge_buffer = sgpnt;
+                cmd->sge_buffer = sg;
 
                 /* use page tables (s/g) */
                 orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);
@@ -1489,9 +1494,9 @@ static void sbp2_prep_command_orb_sg(struct sbp2_command_orb *orb,
 
                 /* loop through and fill out our SBP-2 page tables
                  * (and split up anything too large) */
-                for (i = 0, sg_count = 0 ; i < count; i++, sgpnt++) {
-                        sg_len = sg_dma_len(sgpnt);
-                        sg_addr = sg_dma_address(sgpnt);
+                for (i = 0, sg_count = 0; i < count; i++, sg = sg_next(sg)) {
+                        sg_len = sg_dma_len(sg);
+                        sg_addr = sg_dma_address(sg);
                         while (sg_len) {
                                 sg_element[sg_count].segment_base_lo = sg_addr;
                                 if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
@@ -1521,11 +1526,10 @@ static void sbp2_create_command_orb(struct sbp2_lu *lu,
                                     unchar *scsi_cmd,
                                     unsigned int scsi_use_sg,
                                     unsigned int scsi_request_bufflen,
-                                    void *scsi_request_buffer,
+                                    struct scatterlist *sg,
                                     enum dma_data_direction dma_dir)
 {
         struct sbp2_fwhost_info *hi = lu->hi;
-        struct scatterlist *sgpnt = (struct scatterlist *)scsi_request_buffer;
         struct sbp2_command_orb *orb = &cmd->command_orb;
         u32 orb_direction;
 
@@ -1560,7 +1564,7 @@ static void sbp2_create_command_orb(struct sbp2_lu *lu,
                 orb->data_descriptor_lo = 0x0;
                 orb->misc |= ORB_SET_DIRECTION(1);
         } else
-                sbp2_prep_command_orb_sg(orb, hi, cmd, scsi_use_sg, sgpnt,
+                sbp2_prep_command_orb_sg(orb, hi, cmd, scsi_use_sg, sg,
                                          orb_direction, dma_dir);
 
         sbp2util_cpu_to_be32_buffer(orb, sizeof(*orb));
@@ -1650,7 +1654,6 @@ static int sbp2_send_command(struct sbp2_lu *lu, struct scsi_cmnd *SCpnt,
                              void (*done)(struct scsi_cmnd *))
 {
         unchar *scsi_cmd = (unchar *)SCpnt->cmnd;
-        unsigned int request_bufflen = scsi_bufflen(SCpnt);
         struct sbp2_command_info *cmd;
 
         cmd = sbp2util_allocate_command_orb(lu, SCpnt, done);
@@ -1658,7 +1661,7 @@ static int sbp2_send_command(struct sbp2_lu *lu, struct scsi_cmnd *SCpnt,
                 return -EIO;
 
         sbp2_create_command_orb(lu, cmd, scsi_cmd, scsi_sg_count(SCpnt),
-                                request_bufflen, scsi_sglist(SCpnt),
+                                scsi_bufflen(SCpnt), scsi_sglist(SCpnt),
                                 SCpnt->sc_data_direction);
         sbp2_link_orb_command(lu, cmd);
 
@@ -1987,6 +1990,8 @@ static int sbp2scsi_slave_configure(struct scsi_device *sdev)
                 sdev->skip_ms_page_8 = 1;
         if (lu->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
                 sdev->fix_capacity = 1;
+        if (lu->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
+                blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
         return 0;
 }
 
@@ -2093,9 +2098,6 @@ static int sbp2_module_init(void)
                 sbp2_shost_template.cmd_per_lun = 1;
         }
 
-        if (sbp2_default_workarounds & SBP2_WORKAROUND_128K_MAX_TRANS &&
-            (sbp2_max_sectors * 512) > (128 * 1024))
-                sbp2_max_sectors = 128 * 1024 / 512;
         sbp2_shost_template.max_sectors = sbp2_max_sectors;
 
         hpsb_register_highlevel(&sbp2_highlevel);