From: Florian Fainelli <f.fainelli@gmail.com>
Date: Sat, 5 Oct 2019 15:05:18 -0700
Subject: net: dsa: b53: Do not clear existing mirrored port mask
Git-commit: c763ac436b668d7417f0979430ec0312ede4093d
Patch-mainline: 5.4-rc4
References: networking-stable-19_11_05

Clearing the existing bitmask of mirrored ports essentially prevents us
from capturing more than one port at any given time. This is clearly
wrong, do not clear the bitmask prior to setting up the new port.

Reported-by: Hubert Feurstein <h.feurstein@gmail.com>
Fixes: ed3af5fd08eb ("net: dsa: b53: Add support for port mirroring")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/net/dsa/b53/b53_common.c |    1 -
 1 file changed, 1 deletion(-)

--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1495,7 +1495,6 @@ int b53_mirror_add(struct dsa_switch *ds
 		loc = B53_EG_MIR_CTL;
 
 	b53_read16(dev, B53_MGMT_PAGE, loc, &reg);
-	reg &= ~MIRROR_MASK;
 	reg |= BIT(port);
 	b53_write16(dev, B53_MGMT_PAGE, loc, reg);