[PATCH 3/8] scsi: hisi_sas: Do not modify upper fields of PROG_PHY_LINK_RATE reg

[John Garry]

From: Luo Jiaxing <luojiaxing@xxxxxxxxxx>

When we update register of PROG_PHY_LINK_RATE to set linkrate for a phy,
we used a hard-coded initial value instead of getting the current value
from register. We had assumed that this register would not be modified,
but in fact it was partially modified in new version of hardware. So
hard-coded value we used change default value of register to a wrong
setting and make SAS controller can not change linkrate for phy at new
version of hardware.

So we delete hard-coded value and always read the latest value of register
before we update part of it.

Signed-off-by: Luo Jiaxing <luojiaxing@xxxxxxxxxx>
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 05b60cdf6b24..b7d94f2e49ae 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -191,6 +191,8 @@
 #define PHY_CFG_PHY_RST_OFF		3
 #define PHY_CFG_PHY_RST_MSK		(0x1 << PHY_CFG_PHY_RST_OFF)
 #define PROG_PHY_LINK_RATE		(PORT_BASE + 0x8)
+#define CFG_PROG_PHY_LINK_RATE_OFF	0
+#define CFG_PROG_PHY_LINK_RATE_MSK	(0xff << CFG_PROG_PHY_LINK_RATE_OFF)
 #define CFG_PROG_OOB_PHY_LINK_RATE_OFF	8
 #define CFG_PROG_OOB_PHY_LINK_RATE_MSK	(0xf << CFG_PROG_OOB_PHY_LINK_RATE_OFF)
 #define PHY_CTRL			(PORT_BASE + 0x14)
@@ -598,20 +600,19 @@ static void init_reg_v3_hw(struct hisi_hba *hisi_hba)
 	hisi_sas_write32(hisi_hba, HYPER_STREAM_ID_EN_CFG, 1);
 
 	for (i = 0; i < hisi_hba->n_phy; i++) {
+		enum sas_linkrate max;
 		struct hisi_sas_phy *phy = &hisi_hba->phy[i];
 		struct asd_sas_phy *sas_phy = &phy->sas_phy;
-		u32 prog_phy_link_rate = 0x800;
+		u32 prog_phy_link_rate = hisi_sas_phy_read32(hisi_hba, i,
+							   PROG_PHY_LINK_RATE);
 
+		prog_phy_link_rate &= ~CFG_PROG_PHY_LINK_RATE_MSK;
 		if (!sas_phy->phy || (sas_phy->phy->maximum_linkrate <
-				SAS_LINK_RATE_1_5_GBPS)) {
-			prog_phy_link_rate = 0x855;
-		} else {
-			enum sas_linkrate max = sas_phy->phy->maximum_linkrate;
-
-			prog_phy_link_rate =
-				hisi_sas_get_prog_phy_linkrate_mask(max) |
-				0x800;
-		}
+				SAS_LINK_RATE_1_5_GBPS))
+			max = SAS_LINK_RATE_12_0_GBPS;
+		else
+			max = sas_phy->phy->maximum_linkrate;
+		prog_phy_link_rate |= hisi_sas_get_prog_phy_linkrate_mask(max);
 		hisi_sas_phy_write32(hisi_hba, i, PROG_PHY_LINK_RATE,
 			prog_phy_link_rate);
 		hisi_sas_phy_write32(hisi_hba, i, SERDES_CFG, 0xffc00);
@@ -2501,8 +2502,10 @@ static void phy_set_linkrate_v3_hw(struct hisi_hba *hisi_hba, int phy_no,
 		struct sas_phy_linkrates *r)
 {
 	enum sas_linkrate max = r->maximum_linkrate;
-	u32 prog_phy_link_rate = 0x800;
+	u32 prog_phy_link_rate = hisi_sas_phy_read32(hisi_hba, phy_no,
+						     PROG_PHY_LINK_RATE);
 
+	prog_phy_link_rate &= ~CFG_PROG_PHY_LINK_RATE_MSK;
 	prog_phy_link_rate |= hisi_sas_get_prog_phy_linkrate_mask(max);
 	hisi_sas_phy_write32(hisi_hba, phy_no, PROG_PHY_LINK_RATE,
 			     prog_phy_link_rate);
-- 
2.26.2