diff mbox series

[net-next,v3] net: ethernet: ti: am65-cpsw: VLAN-aware CPSW only if !DSA

Message ID 20250110125737.546184-1-alexander.sverdlin@siemens.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series [net-next,v3] net: ethernet: ti: am65-cpsw: VLAN-aware CPSW only if !DSA | expand

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Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: edumazet@google.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 22 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest fail net-next-2025-01-10--18-00 (tests: 647)

Commit Message

A. Sverdlin Jan. 10, 2025, 12:57 p.m. UTC 
From: Alexander Sverdlin <alexander.sverdlin@siemens.com>

Only configure VLAN-aware CPSW mode if no port is used as DSA CPU port.
VLAN-aware mode interferes with some DSA tagging schemes and makes stacking
DSA switches downstream of CPSW impossible. Previous attempts to address
the issue linked below.

Link: https://lore.kernel.org/netdev/20240227082815.2073826-1-s-vadapalli@ti.com/
Link: https://lore.kernel.org/linux-arm-kernel/4699400.vD3TdgH1nR@localhost/
Co-developed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
---
v3: Moved the AM65_CPSW_CTL_VLAN_AWARE deassertion into
    am65_cpsw_nuss_ndo_slave_open()
v2: Thanks to Siddharth it does look much clearer now (conditionally clear
    AM65_CPSW_CTL_VLAN_AWARE instead of setting)

 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index 5465bf872734..9e52928ebfd4 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -32,6 +32,7 @@ 
 #include <linux/dma/ti-cppi5.h>
 #include <linux/dma/k3-udma-glue.h>
 #include <net/page_pool/helpers.h>
+#include <net/dsa.h>
 #include <net/switchdev.h>
 
 #include "cpsw_ale.h"
@@ -1014,6 +1015,15 @@  static int am65_cpsw_nuss_ndo_slave_open(struct net_device *ndev)
 
 	common->usage_count++;
 
+	/* VLAN aware CPSW mode is incompatible with some DSA tagging schemes.
+	 * Therefore disable VLAN_AWARE mode if any of the ports is a DSA Port.
+	 */
+	if (netdev_uses_dsa(ndev)) {
+		reg = readl(common->cpsw_base + AM65_CPSW_REG_CTL);
+		reg &= ~AM65_CPSW_CTL_VLAN_AWARE;
+		writel(reg, common->cpsw_base + AM65_CPSW_REG_CTL);
+	}
+
 	am65_cpsw_port_set_sl_mac(port, ndev->dev_addr);
 	am65_cpsw_port_enable_dscp_map(port);