From: Vincent Whitchurch vincent.whitchurch@axis.com
[ 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@axis.com Reviewed-by: Simon Horman simon.horman@corigine.com Link: https://lore.kernel.org/r/20230721-stmmac-tx-workaround-v1-1-9411cbd5ee07@ax... Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 df41eac54058f..03ceb6a940732 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c @@ -240,13 +240,15 @@ void stmmac_dwmac4_set_mac_addr(void __iomem *ioaddr, const 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,