From: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
[ Upstream commit 284779dbf4e98753458708783af8c35630674a21 ]
commit a3a57bf07de23fe1ff779e0fdf710aa581c3ff73 ("net: stmmac: work
around sporadic tx issue on link-up") worked around a problem with TX
sometimes not working after a link-up by avoiding a redundant write to
MAC_CTRL_REG (aka GMAC_CONFIG), since the IP appeared to have problems
with handling multiple writes to that register in some cases.
That commit however only added the work around to dwmac_lib.c (apart
from the common code in stmmac_main.c), but my systems with version
4.21a of the IP exhibit the same problem, so add the work around to
dwmac4_lib.c too.
Fixes: a3a57bf07de2 ("net: stmmac: work around sporadic tx issue on link-up")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230721-stmmac-tx-workaround-v1-1-9411cbd5ee07@xxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c
index 9292a1fab7d32..7011c08d2e012 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c
@@ -207,13 +207,15 @@ void stmmac_dwmac4_set_mac_addr(void __iomem *ioaddr, u8 addr[6],
void stmmac_dwmac4_set_mac(void __iomem *ioaddr, bool enable)
{
u32 value = readl(ioaddr + GMAC_CONFIG);
+ u32 old_val = value;
if (enable)
value |= GMAC_CONFIG_RE | GMAC_CONFIG_TE;
else
value &= ~(GMAC_CONFIG_TE | GMAC_CONFIG_RE);
- writel(value, ioaddr + GMAC_CONFIG);
+ if (value != old_val)
+ writel(value, ioaddr + GMAC_CONFIG);
}
void stmmac_dwmac4_get_mac_addr(void __iomem *ioaddr, unsigned char *addr,
--
2.39.2
