lkml.org 
[lkml]   [2018]   [Feb]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL for 4.14 039/110] net: stmmac: Fix TX timestamp calculation
Date
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>
---
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;
}
--
2.11.0
\
 
 \ /
  Last update: 2018-02-03 19:52    [W:0.232 / U:6.808 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site