From 200922c93f008e03ddc804c6dacdf26ca1ba86d7 Mon Sep 17 00:00:00 2001 From: Fredrik Hallenberg Date: Mon, 18 Dec 2017 23:33:59 +0100 Subject: [PATCH] net: stmmac: Fix TX timestamp calculation 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 Signed-off-by: David S. Miller --- 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 721b61655261..08c19ebd5306 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; } -- 2.20.1