From: Jan Sokolowski <jan.sokolowski@intel.com>
Date: Mon, 9 Oct 2017 13:08:28 -0700
Subject: IB/hfi1: Fix serdes loopback set-up
Patch-mainline: v4.15-rc1
Git-commit: 242b494bf22be4056df1493664b00b5d0b238e53
References: bsc#1096793 FATE#325050

Change serdes mode setting to use MISC_CONFIG_BITS in
VERIFY_CAP_LOCAL_LINK_WIDTH register. This method of
setting up serdes loopback is universally compatible
across all firmware versions.

Reviewed-by: Jakub Byczkowski <jakub.byczkowski@intel.com>
Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/hfi1/chip.c |   42 ++++++++++++--------------------------
 drivers/infiniband/hw/hfi1/chip.h |    3 ++
 2 files changed, 17 insertions(+), 28 deletions(-)

--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -9190,25 +9190,6 @@ static int do_quick_linkup(struct hfi1_d
 }
 
 /*
- * Set the SerDes to internal loopback mode.
- * Returns 0 on success, -errno on error.
- */
-static int set_serdes_loopback_mode(struct hfi1_devdata *dd)
-{
-	int ret;
-
-	ret = set_physical_link_state(dd, PLS_INTERNAL_SERDES_LOOPBACK);
-	if (ret == HCMD_SUCCESS)
-		return 0;
-	dd_dev_err(dd,
-		   "Set physical link state to SerDes Loopback failed with return %d\n",
-		   ret);
-	if (ret >= 0)
-		ret = -EINVAL;
-	return ret;
-}
-
-/*
  * Do all special steps to set up loopback.
  */
 static int init_loopback(struct hfi1_devdata *dd)
@@ -9233,13 +9214,11 @@ static int init_loopback(struct hfi1_dev
 		return 0;
 	}
 
-	/* handle serdes loopback */
-	if (loopback == LOOPBACK_SERDES) {
-		/* internal serdes loopack needs quick linkup on RTL */
-		if (dd->icode == ICODE_RTL_SILICON)
-			quick_linkup = 1;
-		return set_serdes_loopback_mode(dd);
-	}
+	/*
+	 * SerDes loopback init sequence is handled in set_local_link_attributes
+	 */
+	if (loopback == LOOPBACK_SERDES)
+		return 0;
 
 	/* LCB loopback - handled at poll time */
 	if (loopback == LOOPBACK_LCB) {
@@ -9298,7 +9277,7 @@ static int set_local_link_attributes(str
 	u8 tx_polarity_inversion;
 	u8 rx_polarity_inversion;
 	int ret;
-
+	u32 misc_bits = 0;
 	/* reset our fabric serdes to clear any lingering problems */
 	fabric_serdes_reset(dd);
 
@@ -9344,7 +9323,14 @@ static int set_local_link_attributes(str
 	if (ret != HCMD_SUCCESS)
 		goto set_local_link_attributes_fail;
 
-	ret = write_vc_local_link_width(dd, 0, 0,
+	/*
+	 * SerDes loopback init sequence requires
+	 * setting bit 0 of MISC_CONFIG_BITS
+	 */
+	if (loopback == LOOPBACK_SERDES)
+		misc_bits |= 1 << LOOPBACK_SERDES_CONFIG_BIT_MASK_SHIFT;
+
+	ret = write_vc_local_link_width(dd, misc_bits, 0,
 					opa_to_vc_link_widths(
 						ppd->link_width_enabled));
 	if (ret != HCMD_SUCCESS)
--- a/drivers/infiniband/hw/hfi1/chip.h
+++ b/drivers/infiniband/hw/hfi1/chip.h
@@ -583,6 +583,9 @@ enum {
 #define LOOPBACK_LCB	2
 #define LOOPBACK_CABLE	3	/* external cable */
 
+/* set up serdes bit in MISC_CONFIG_BITS */
+#define LOOPBACK_SERDES_CONFIG_BIT_MASK_SHIFT 0
+
 /* read and write hardware registers */
 u64 read_csr(const struct hfi1_devdata *dd, u32 offset);
 void write_csr(const struct hfi1_devdata *dd, u32 offset, u64 value);