staging/rdma/hfi1: Add one-time LCB reset

Add one-time LCB reset on driver load to pre-emptively work
around any LCB power cycle issues.
Reviewed-by: NEaswar Hariharan <easwar.hariharan@intel.com>
Signed-off-by: NDean Luick <dean.luick@intel.com>
Signed-off-by: NJubin John <jubin.john@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rdma/hfi1/chip.c

@@ -5896,6 +5896,23 @@ void init_qsfp(struct hfi1_pportdata *ppd)
 	}
 }
 
+/*
+ * Do a one-time initialize of the LCB block.
+ */
+static void init_lcb(struct hfi1_devdata *dd)
+{
+	/* the DC has been reset earlier in the driver load */
+
+	/* set LCB for cclk loopback on the port */
+	write_csr(dd, DC_LCB_CFG_TX_FIFOS_RESET, 0x01);
+	write_csr(dd, DC_LCB_CFG_LANE_WIDTH, 0x00);
+	write_csr(dd, DC_LCB_CFG_REINIT_AS_SLAVE, 0x00);
+	write_csr(dd, DC_LCB_CFG_CNT_FOR_SKIP_STALL, 0x110);
+	write_csr(dd, DC_LCB_CFG_CLK_CNTR, 0x08);
+	write_csr(dd, DC_LCB_CFG_LOOPBACK, 0x02);
+	write_csr(dd, DC_LCB_CFG_TX_FIFOS_RESET, 0x00);
+}
+
 int bringup_serdes(struct hfi1_pportdata *ppd)
 {
 	struct hfi1_devdata *dd = ppd->dd;
@@ -5917,6 +5934,9 @@ int bringup_serdes(struct hfi1_pportdata *ppd)
 	/* Set linkinit_reason on power up per OPA spec */
 	ppd->linkinit_reason = OPA_LINKINIT_REASON_LINKUP;
 
+	/* one-time init of the LCB */
+	init_lcb(dd);
+
 	if (loopback) {
 		ret = init_loopback(dd);
 		if (ret < 0)

drivers/staging/rdma/hfi1/chip_registers.h

@@ -318,6 +318,9 @@
 #define DC_LCB_CFG_TX_FIFOS_RADR_RST_VAL_SHIFT 0
 #define DC_LCB_CFG_TX_FIFOS_RESET (DC_LCB_CSRS + 0x000000000008)
 #define DC_LCB_CFG_TX_FIFOS_RESET_VAL_SHIFT 0
+#define DC_LCB_CFG_REINIT_AS_SLAVE (DC_LCB_CSRS + 0x000000000030)
+#define DC_LCB_CFG_CNT_FOR_SKIP_STALL (DC_LCB_CSRS + 0x000000000040)
+#define DC_LCB_CFG_CLK_CNTR (DC_LCB_CSRS + 0x000000000110)
 #define DC_LCB_ERR_CLR (DC_LCB_CSRS + 0x000000000308)
 #define DC_LCB_ERR_EN (DC_LCB_CSRS + 0x000000000310)
 #define DC_LCB_ERR_FLG (DC_LCB_CSRS + 0x000000000300)