[PATCH net-next v3 10/14] net: dsa: b53: prevent BRCM_HDR access on older devices
From: Álvaro Fernández Rojas <hidden>
Date: 2025-06-12 08:38:05
Also in:
lkml
Subsystem:
broadcom b53/sf2 ethernet switch driver, networking drivers, networking [dsa], the rest · Maintainers:
Florian Fainelli, Jonas Gorski, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Vladimir Oltean, Linus Torvalds
Older switches don't implement BRCM_HDR register so we should avoid
reading or writing it.
Fixes: b409a9efa183 ("net: dsa: b53: Move Broadcom header setup to b53")
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Álvaro Fernández Rojas <redacted>
---
drivers/net/dsa/b53/b53_common.c | 5 +++++
1 file changed, 5 insertions(+)
v3: add changes requested by Jonas:
- Check for legacy tag protocols instead of is5325().
v2: no changes
diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index 1ecadcd84a283..d082e5a851ab5 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c@@ -730,6 +730,11 @@ void b53_brcm_hdr_setup(struct dsa_switch *ds, int port) hdr_ctl |= GC_FRM_MGMT_PORT_M; b53_write8(dev, B53_MGMT_PAGE, B53_GLOBAL_CONFIG, hdr_ctl); + /* B53_BRCM_HDR not present on devices with legacy tags */ + if (dev->tag_protocol == DSA_TAG_PROTO_BRCM_LEGACY || + dev->tag_protocol == DSA_TAG_PROTO_BRCM_LEGACY_FCS) + return; + /* Enable Broadcom tags for IMP port */ b53_read8(dev, B53_MGMT_PAGE, B53_BRCM_HDR, &hdr_ctl); if (tag_en)
--
2.39.5