4.9-stable review patch. If anyone has any objections, please let me know.
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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@microsoft.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 @@ -38,6 +38,7 @@ 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 @@ -54,10 +55,11 @@ 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; }