megaraid_sas: Do not use PAGE_SIZE for max_sectors

commit 357ae967ad66e357f78b5cfb5ab6ca07fb4a7758 upstream.

Do not use PAGE_SIZE marco to calculate max_sectors per I/O
request. Driver code assumes PAGE_SIZE will be always 4096 which can
lead to wrongly calculated value if PAGE_SIZE is not 4096. This issue
was reported in Ubuntu Bugzilla Bug #1475166.

Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index 049c22f..458fb34 100644 (file)
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -300,6 +300,8 @@ enum MR_EVT_ARGS {
        MR_EVT_ARGS_GENERIC,
 };
 
+
+#define SGE_BUFFER_SIZE        4096
 /*
  * define constants for device list query options
  */

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index e45c865..47023b4 100644 (file)
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -3636,7 +3636,7 @@ static int megasas_init_fw(struct megasas_instance *instance)
        }
 
        instance->max_sectors_per_req = instance->max_num_sge *
-                                               PAGE_SIZE / 512;
+                                               SGE_BUFFER_SIZE / 512;
        if (tmp_sectors && (instance->max_sectors_per_req > tmp_sectors))
                instance->max_sectors_per_req = tmp_sectors;