[SCSI] aic79xx: SLOWCRC fix

This patch introduces the SLOWCRC handling for certain buggy chipsets.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/scsi/aic7xxx/aic79xx_osm.c b/drivers/scsi/aic7xxx/aic79xx_osm.c
index 2567e29960bd..815c06312c88 100644
--- a/drivers/scsi/aic7xxx/aic79xx_osm.c
+++ b/drivers/scsi/aic7xxx/aic79xx_osm.c
@@ -314,6 +314,21 @@ static uint32_t aic79xx_seltime;
  */
 uint32_t aic79xx_periodic_otag;
 
+/* Some storage boxes are using an LSI chip which has a bug making it
+ * impossible to use aic79xx Rev B chip in 320 speeds.  The following
+ * storage boxes have been reported to be buggy:
+ * EonStor 3U 16-Bay: U16U-G3A3
+ * EonStor 2U 12-Bay: U12U-G3A3
+ * SentinelRAID: 2500F R5 / R6
+ * SentinelRAID: 2500F R1
+ * SentinelRAID: 2500F/1500F
+ * SentinelRAID: 150F
+ * 
+ * To get around this LSI bug, you can set your board to 160 mode
+ * or you can enable the SLOWCRC bit.
+ */
+uint32_t aic79xx_slowcrc;
+
 /*
  * Module information and settable options.
  */
@@ -343,6 +358,7 @@ MODULE_PARM_DESC(aic79xx,
 "       amplitude:<int>         Set the signal amplitude (0-7).\n"
 "       seltime:<int>           Selection Timeout:\n"
 "                               (0/256ms,1/128ms,2/64ms,3/32ms)\n"
+"       slowcrc                 Turn on the SLOWCRC bit (Rev B only)\n"          
 "\n"
 "       Sample /etc/modprobe.conf line:\n"
 "               Enable verbose logging\n"
@@ -1003,6 +1019,7 @@ aic79xx_setup(char *s)
                 { "slewrate", NULL },
                 { "precomp", NULL },
                 { "amplitude", NULL },
+                { "slowcrc", &aic79xx_slowcrc },
         };
 
         end = strchr(s, '\0');