This is a note to let you know that I've just added the patch titled

net: stmmac: Fix TX timestamp calculation

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: net-stmmac-fix-tx-timestamp-calculation.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Wed Feb 28 16:23:28 CET 2018

From: Fredrik Hallenberg megahallon@gmail.com Date: Mon, 18 Dec 2017 23:33:59 +0100 Subject: net: stmmac: Fix TX timestamp calculation

From: Fredrik Hallenberg megahallon@gmail.com

[ Upstream commit 200922c93f008e03ddc804c6dacdf26ca1ba86d7 ]

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: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

--- 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_incr { 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_incr

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; }

Patches currently in stable-queue which might be from megahallon@gmail.com are

queue-4.14/net-stmmac-fix-tx-timestamp-calculation.patch queue-4.14/net-stmmac-fix-bad-rx-timestamp-extraction.patch