[PATCH net 2/2] net: bcmasp: fix tx_spb_ring_full() checking same slot cnt times

[Danesh Petigara <danesh.petigara@broadcom.com>]

From: Justin Chen <justin.chen@broadcom.com>

The loop initialised next_index from intf->tx_spb_index on every
iteration, so incr_ring() always produced the same result and only
one slot was ever tested.  Move the initialisation before the loop
so each iteration advances next_index and the function correctly
checks that cnt consecutive descriptor slots are available before
allowing a new transmission.

Fixes: 490cb412007d ("net: bcmasp: Add support for ASP2.0 Ethernet controller")
Signed-off-by: Justin Chen <justin.chen@broadcom.com>
Assisted-by: Claude:claude-sonnet-4-6 vscode
Signed-off-by: Danesh Petigara <danesh.petigara@broadcom.com>
---
 drivers/net/ethernet/broadcom/asp2/bcmasp_intf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/asp2/bcmasp_intf.c b/drivers/net/ethernet/broadcom/asp2/bcmasp_intf.c
index 2bd035f74fa2..f2176ef3a127 100644
--- a/drivers/net/ethernet/broadcom/asp2/bcmasp_intf.c
+++ b/drivers/net/ethernet/broadcom/asp2/bcmasp_intf.c
@@ -148,8 +148,9 @@ static int tx_spb_ring_full(struct bcmasp_intf *intf, int cnt)
 	int next_index, i;
 
 	/* Check if we have enough room for cnt descriptors */
+	next_index = intf->tx_spb_index;
 	for (i = 0; i < cnt; i++) {
-		next_index = incr_ring(intf->tx_spb_index, DESC_RING_COUNT);
+		next_index = incr_ring(next_index, DESC_RING_COUNT);
 		if (next_index == intf->tx_spb_clean_index)
 			return 1;
 	}
-- 
2.54.0