From 847265678ec5731db38fd928a365539a8581e31d Mon Sep 17 00:00:00 2001 From: Vincent Whitchurch Date: Fri, 21 Jul 2023 15:39:20 +0200 Subject: net: stmmac: Apply redundant write work around on 4.xx too [ 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 Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230721-stmmac-tx-workaround-v1-1-9411cbd5ee07@axis.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/net/ethernet') diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_lib.c index d1c605777985..7c26394f665e 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, 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, -- cgit v1.2.3