diff mbox series

[net] nfp: flower: remove headroom from max MTU calculation

Message ID 20180509071858.11124-1-jakub.kicinski@netronome.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series [net] nfp: flower: remove headroom from max MTU calculation | expand

Commit Message

Jakub Kicinski May 9, 2018, 7:18 a.m. UTC 
From: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>

Since commit 29a5dcae2790 ("nfp: flower: offload phys port MTU change") we
take encapsulation headroom into account when calculating the max allowed
MTU.  This is unnecessary as the max MTU advertised by firmware should have
already accounted for encap headroom.

Subtracting headroom twice brings the max MTU below what's necessary for
some deployments.

Fixes: 29a5dcae2790 ("nfp: flower: offload phys port MTU change")
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 .../net/ethernet/netronome/nfp/flower/main.c  | 19 -------------------
 1 file changed, 19 deletions(-)

Comments

David Miller May 10, 2018, 7:28 p.m. UTC | #1 
From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Wed,  9 May 2018 00:18:58 -0700

> From: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
> 
> Since commit 29a5dcae2790 ("nfp: flower: offload phys port MTU change") we
> take encapsulation headroom into account when calculating the max allowed
> MTU.  This is unnecessary as the max MTU advertised by firmware should have
> already accounted for encap headroom.
> 
> Subtracting headroom twice brings the max MTU below what's necessary for
> some deployments.
> 
> Fixes: 29a5dcae2790 ("nfp: flower: offload phys port MTU change")
> Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
> Reviewed-by: John Hurley <john.hurley@netronome.com>
> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>

Applied.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/netronome/nfp/flower/main.c b/drivers/net/ethernet/netronome/nfp/flower/main.c
index a997e34bcec2..84e3b9f5abb1 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/main.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/main.c
@@ -52,8 +52,6 @@ 
 
 #define NFP_FLOWER_ALLOWED_VER 0x0001000000010000UL
 
-#define NFP_FLOWER_FRAME_HEADROOM	158
-
 static const char *nfp_flower_extra_cap(struct nfp_app *app, struct nfp_net *nn)
 {
 	return "FLOWER";
@@ -559,22 +557,6 @@  static void nfp_flower_clean(struct nfp_app *app)
 	app->priv = NULL;
 }
 
-static int
-nfp_flower_check_mtu(struct nfp_app *app, struct net_device *netdev,
-		     int new_mtu)
-{
-	/* The flower fw reserves NFP_FLOWER_FRAME_HEADROOM bytes of the
-	 * supported max MTU to allow for appending tunnel headers. To prevent
-	 * unexpected behaviour this needs to be accounted for.
-	 */
-	if (new_mtu > netdev->max_mtu - NFP_FLOWER_FRAME_HEADROOM) {
-		nfp_err(app->cpp, "New MTU (%d) is not valid\n", new_mtu);
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
 static bool nfp_flower_check_ack(struct nfp_flower_priv *app_priv)
 {
 	bool ret;
@@ -656,7 +638,6 @@  const struct nfp_app_type app_flower = {
 	.init		= nfp_flower_init,
 	.clean		= nfp_flower_clean,
 
-	.check_mtu	= nfp_flower_check_mtu,
 	.repr_change_mtu  = nfp_flower_repr_change_mtu,
 
 	.vnic_alloc	= nfp_flower_vnic_alloc,