From 9b477f00c55f8476728dc87079ee52a37ec4e406 Mon Sep 17 00:00:00 2001
From: Fredrik Hallenberg <megahallon@gmail.com>
Date: Mon, 18 Dec 2017 23:33:59 +0100
Subject: [PATCH 10/21] net: stmmac: Fix TX timestamp calculation
Git-commit: 200922c93f008e03ddc804c6dacdf26ca1ba86d7
Patch-mainline: v4.15-rc5
References: git-fixes
When using GMAC4 the value written in PTP_SSIR should be shifted however
the shifted value is also used in subsequent calculations which results
in a bad timestamp value.
Signed-off-by: Fredrik Hallenberg <megahallon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index bcbc992edf11..41d528fbebb4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -34,6 +34,7 @@ static u32 stmmac_config_sub_second_increment(void __iomem *ioaddr,
{
u32 value = readl(ioaddr + PTP_TCR);
unsigned long data;
+ u32 reg_value;
/* For GMAC3.x, 4.x versions, convert the ptp_clock to nano second
* formula = (1/ptp_clock) * 1000000000
@@ -50,10 +51,11 @@ static u32 stmmac_config_sub_second_increment(void __iomem *ioaddr,
data &= PTP_SSIR_SSINC_MASK;
+ reg_value = data;
if (gmac4)
- data = data << GMAC4_PTP_SSIR_SSINC_SHIFT;
+ reg_value <<= GMAC4_PTP_SSIR_SSINC_SHIFT;
- writel(data, ioaddr + PTP_SSIR);
+ writel(reg_value, ioaddr + PTP_SSIR);
return data;
}
--
2.16.4