diff mbox series

[net,v3,1/2] net: ravb: Fix maximum TX frame size for GbEth devices

Message ID 20240918081839.259-2-paul.barker.ct@bp.renesas.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series Fix maximum TX/RX frame sizes in ravb driver | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 11 of 11 maintainers
netdev/build_clang success Errors and warnings before: 16 this patch: 16
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 Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 16 this patch: 16
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 43 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 success net-next-2024-09-19--09-00 (tests: 764)

Commit Message

Paul Barker Sept. 18, 2024, 8:18 a.m. UTC 
The datasheets for all SoCs using the GbEth IP specify a maximum
transmission frame size of 1.5 kByte. I've confirmed through internal
discussions that support for 1522 byte frames has been validated, which
allows us to support the default MTU of 1500 bytes after reserving space
for the Ethernet header, frame checksums and an optional VLAN tag.

Fixes: 2e95e08ac009 ("ravb: Add rx_max_buf_size to struct ravb_hw_info")
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
---
 drivers/net/ethernet/renesas/ravb.h      | 1 +
 drivers/net/ethernet/renesas/ravb_main.c | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

Comments

Simon Horman Sept. 19, 2024, 7:24 a.m. UTC | #1 
On Wed, Sep 18, 2024 at 09:18:38AM +0100, Paul Barker wrote:
> The datasheets for all SoCs using the GbEth IP specify a maximum
> transmission frame size of 1.5 kByte. I've confirmed through internal
> discussions that support for 1522 byte frames has been validated, which
> allows us to support the default MTU of 1500 bytes after reserving space
> for the Ethernet header, frame checksums and an optional VLAN tag.
> 
> Fixes: 2e95e08ac009 ("ravb: Add rx_max_buf_size to struct ravb_hw_info")
> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
> Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>

Reviewed-by: Simon Horman <horms@kernel.org>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index 9893c91af105..a7de5cf6b317 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -1052,6 +1052,7 @@  struct ravb_hw_info {
 	netdev_features_t net_features;
 	int stats_len;
 	u32 tccr_mask;
+	u32 tx_max_frame_size;
 	u32 rx_max_frame_size;
 	u32 rx_buffer_size;
 	u32 rx_desc_size;
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index c7ec23688d56..e73cdba58516 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2674,6 +2674,7 @@  static const struct ravb_hw_info ravb_gen2_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)),
@@ -2696,6 +2697,7 @@  static const struct ravb_hw_info ravb_gen3_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)),
@@ -2721,6 +2723,7 @@  static const struct ravb_hw_info ravb_gen4_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)),
@@ -2770,6 +2773,7 @@  static const struct ravb_hw_info gbeth_hw_info = {
 	.net_features = NETIF_F_RXCSUM | NETIF_F_HW_CSUM,
 	.stats_len = ARRAY_SIZE(ravb_gstrings_stats_gbeth),
 	.tccr_mask = TCCR_TSRQ0,
+	.tx_max_frame_size = 1522,
 	.rx_max_frame_size = SZ_8K,
 	.rx_buffer_size = SZ_2K,
 	.rx_desc_size = sizeof(struct ravb_rx_desc),
@@ -2981,7 +2985,7 @@  static int ravb_probe(struct platform_device *pdev)
 	priv->avb_link_active_low =
 		of_property_read_bool(np, "renesas,ether-link-active-low");
 
-	ndev->max_mtu = info->rx_max_frame_size -
+	ndev->max_mtu = info->tx_max_frame_size -
 		(ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN);
 	ndev->min_mtu = ETH_MIN_MTU;