idpf: don't skip over ethtool tcp-data-split setting

[PATCH net] idpf: don't skip over ethtool tcp-data-split setting

Posted by Michal Schmidt 1 year, 7 months ago

Disabling tcp-data-split on idpf silently fails:
  # ethtool -G $NETDEV tcp-data-split off
  # ethtool -g $NETDEV | grep 'TCP data split'
  TCP data split:        on

But it works if you also change 'tx' or 'rx':
  # ethtool -G $NETDEV tcp-data-split off tx 256
  # ethtool -g $NETDEV | grep 'TCP data split'
  TCP data split:        off

The bug is in idpf_set_ringparam, where it takes a shortcut out if the
TX and RX sizes are not changing. Fix it by checking also if the
tcp-data-split setting remains unchanged. Only then can the soft reset
be skipped.

Fixes: 9b1aa3ef2328 ("idpf: add get/set for Ethtool's header split ringparam")
Reported-by: Xu Du <xudu@redhat.com>
Closes: https://issues.redhat.com/browse/RHEL-36182
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
---
 drivers/net/ethernet/intel/idpf/idpf_ethtool.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_ethtool.c b/drivers/net/ethernet/intel/idpf/idpf_ethtool.c
index 986d429d1175..6972d728431c 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_ethtool.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_ethtool.c
@@ -376,7 +376,8 @@ static int idpf_set_ringparam(struct net_device *netdev,
 			    new_tx_count);
 
 	if (new_tx_count == vport->txq_desc_count &&
-	    new_rx_count == vport->rxq_desc_count)
+	    new_rx_count == vport->rxq_desc_count &&
+	    kring->tcp_data_split == idpf_vport_get_hsplit(vport))
 		goto unlock_mutex;
 
 	if (!idpf_vport_set_hsplit(vport, kring->tcp_data_split)) {
-- 
2.44.0

Re: [PATCH net] idpf: don't skip over ethtool tcp-data-split setting

Posted by Alexander Lobakin 1 year, 7 months ago

From: Michal Schmidt <mschmidt@redhat.com>
Date: Wed, 15 May 2024 11:24:14 +0200

> Disabling tcp-data-split on idpf silently fails:
>   # ethtool -G $NETDEV tcp-data-split off
>   # ethtool -g $NETDEV | grep 'TCP data split'
>   TCP data split:        on
> 
> But it works if you also change 'tx' or 'rx':
>   # ethtool -G $NETDEV tcp-data-split off tx 256
>   # ethtool -g $NETDEV | grep 'TCP data split'
>   TCP data split:        off

Oh crap >_< I'm sorry, thanks for the fix!

> 
> The bug is in idpf_set_ringparam, where it takes a shortcut out if the
> TX and RX sizes are not changing. Fix it by checking also if the
> tcp-data-split setting remains unchanged. Only then can the soft reset
> be skipped.
> 
> Fixes: 9b1aa3ef2328 ("idpf: add get/set for Ethtool's header split ringparam")
> Reported-by: Xu Du <xudu@redhat.com>
> Closes: https://issues.redhat.com/browse/RHEL-36182
> Signed-off-by: Michal Schmidt <mschmidt@redhat.com>

Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>

> ---
>  drivers/net/ethernet/intel/idpf/idpf_ethtool.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/intel/idpf/idpf_ethtool.c b/drivers/net/ethernet/intel/idpf/idpf_ethtool.c
> index 986d429d1175..6972d728431c 100644
> --- a/drivers/net/ethernet/intel/idpf/idpf_ethtool.c
> +++ b/drivers/net/ethernet/intel/idpf/idpf_ethtool.c
> @@ -376,7 +376,8 @@ static int idpf_set_ringparam(struct net_device *netdev,
>  			    new_tx_count);
>  
>  	if (new_tx_count == vport->txq_desc_count &&
> -	    new_rx_count == vport->rxq_desc_count)
> +	    new_rx_count == vport->rxq_desc_count &&
> +	    kring->tcp_data_split == idpf_vport_get_hsplit(vport))
>  		goto unlock_mutex;
>  
>  	if (!idpf_vport_set_hsplit(vport, kring->tcp_data_split)) {

Olek