[PATCH net-next v4 12/13] net: macb: set MACB_CAPS_USRIO_DISABLED if no usrio config is provided

[Conor Dooley <conor@kernel.org>]

From: Théo Lebrun <theo.lebrun@bootlin.com>

bp->usrio is copied directly from dt_conf->usrio in macb_probe().

If dt_conf->usrio is NULL, we do not want to land in USRIO write
codepaths which dereference bp->usrio. Inherit automatically
MACB_CAPS_USRIO_DISABLED to avoid those.

This means a macb_config that wants to disable usrio can simply drop
its .usrio field, rather than add the disabled capability explicitly.

Nit: drop the dt_conf NULL check because the pointer is always valid.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index b11ef703575b0..1a6cdc223625f 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -4319,8 +4319,10 @@ static void macb_configure_caps(struct macb *bp,
 {
 	u32 dcfg;
 
-	if (dt_conf)
-		bp->caps = dt_conf->caps;
+	bp->caps = dt_conf->caps;
+
+	if (!dt_conf->usrio)
+		bp->caps |= MACB_CAPS_USRIO_DISABLED;
 
 	if (hw_is_gem(bp->regs, bp->native_io)) {
 		bp->caps |= MACB_CAPS_MACB_IS_GEM;
-- 
2.51.0