[SCSI] mvsas: expander write performance enhancement
with 1 expander, connect 8 HDD, the write performance will be
improved by 80%.
Signed-off-by: Xiangliang Yu <yuxiangl@marvell.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/mvsas/mv_94xx.c b/drivers/scsi/mvsas/mv_94xx.c
index 016d3d4..130d803 100644
--- a/drivers/scsi/mvsas/mv_94xx.c
+++ b/drivers/scsi/mvsas/mv_94xx.c
@@ -510,6 +510,15 @@
tmp |= CINT_PHY_MASK;
mw32(MVS_INT_MASK, tmp);
+ /* tune STP performance */
+ tmp = 0x003F003F;
+ mvs_cw32(mvi, CMD_PL_TIMER, tmp);
+
+ /* This can improve expander large block size seq write performance */
+ tmp = mvs_cr32(mvi, CMD_PORT_LAYER_TIMER1);
+ tmp |= 0xFFFF007F;
+ mvs_cw32(mvi, CMD_PORT_LAYER_TIMER1, tmp);
+
/* change the connection open-close behavior (bit 9)
* set bit8 to 1 for performance tuning */
tmp = mvs_cr32(mvi, CMD_SL_MODE0);