[SCSI] megaraid_sas: check max_sgl reported by FW for setting max_sectors_per_req

1. Setting the max_sectors_per_req based on max SGL supported by the
   FW. Prior versions calculated this value from controller info's
   max_sectors_1, max_sectors_2. For certain controllers/FW, this was
   resulting in a value greater than max SGL supported by the FW. Now
   we take the min of max sgl from FW and max_sectors calculation.

2. Increased MFI_POLL_TIMEOUT_SECS to 60 seconds from 10. FW may take
   a max of 60 seconds to respond to the INIT cmd.

Signed-off-by: Bo Yang <bo.yang@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

2 files changed, 10 insertions, 6 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 9aee2544798c..7eefbe0681d6 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -1890,6 +1890,7 @@ static int megasas_init_mfi(struct megasas_instance *instance)
         u32 reply_q_sz;
         u32 max_sectors_1;
         u32 max_sectors_2;
+        u32 tmp_sectors;
         struct megasas_register_set __iomem *reg_set;
         struct megasas_ctrl_info *ctrl_info;
         /*
@@ -1982,17 +1983,20 @@ static int megasas_init_mfi(struct megasas_instance *instance)
          * Note that older firmwares ( < FW ver 30) didn't report information
          * to calculate max_sectors_1. So the number ended up as zero always.
          */
+        tmp_sectors = 0;
         if (ctrl_info && !megasas_get_ctrl_info(instance, ctrl_info)) {
 
                 max_sectors_1 = (1 << ctrl_info->stripe_sz_ops.min) *
                     ctrl_info->max_strips_per_io;
                 max_sectors_2 = ctrl_info->max_request_size;
 
-                instance->max_sectors_per_req = (max_sectors_1 < max_sectors_2)
-                    ? max_sectors_1 : max_sectors_2;
-        } else
-                instance->max_sectors_per_req = instance->max_num_sge *
-                    PAGE_SIZE / 512;
+                tmp_sectors = min_t(u32, max_sectors_1 , max_sectors_2);
+        }
+
+        instance->max_sectors_per_req = instance->max_num_sge *
+                                                PAGE_SIZE / 512;
+        if (tmp_sectors && (instance->max_sectors_per_req > tmp_sectors))
+                instance->max_sectors_per_req = tmp_sectors;
 
         kfree(ctrl_info);
 
diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index f4ab30094621..9739023a222c 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -571,7 +571,7 @@ struct megasas_ctrl_info {
 #define IS_DMA64                                (sizeof(dma_addr_t) == 8)
 
 #define MFI_OB_INTR_STATUS_MASK                 0x00000002
-#define MFI_POLL_TIMEOUT_SECS                   10
+#define MFI_POLL_TIMEOUT_SECS                   60
 
 #define MFI_REPLY_1078_MESSAGE_INTERRUPT        0x80000000