6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paul Barker <paul.barker.ct@xxxxxxxxxxxxxx>
[ Upstream commit e7e441a4100e4bc90b52f80494a28a9667993975 ]
When tx_max_frame_size was added to struct ravb_hw_info, no value was
set in ravb_rzv2m_hw_info so the default value of zero was used.
The maximum MTU is set by subtracting from tx_max_frame_size to allow
space for headers and frame checksums. As ndev->max_mtu is unsigned,
this subtraction wraps around leading to a ridiculously large positive
value that is obviously incorrect.
Before tx_max_frame_size was introduced, the maximum MTU was based on
rx_max_frame_size. So, we can restore the correct maximum MTU by copying
the rx_max_frame_size value into tx_max_frame_size for RZ/V2M.
Fixes: 1d63864299ca ("net: ravb: Fix maximum TX frame size for GbEth devices")
Signed-off-by: Paul Barker <paul.barker.ct@xxxxxxxxxxxxxx>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Reviewed-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
Link: https://patch.msgid.link/20250109113706.1409149-1-paul.barker.ct@xxxxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/renesas/ravb_main.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 907af4651c553..6f6b0566c65bc 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2756,6 +2756,7 @@ static const struct ravb_hw_info ravb_rzv2m_hw_info = {
.net_features = NETIF_F_RXCSUM,
.stats_len = ARRAY_SIZE(ravb_gstrings_stats),
.tccr_mask = TCCR_TSRQ0 | TCCR_TSRQ1 | TCCR_TSRQ2 | TCCR_TSRQ3,
+ .tx_max_frame_size = SZ_2K,
.rx_max_frame_size = SZ_2K,
.rx_buffer_size = SZ_2K +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
--
2.39.5
