Re: [PATCH net-next 2/6] atl1c: remove private tx lock

[Francois Romieu]

Florian Westphal  :
> Francois Romieu  wrote:
[...]
> > Play it safe and keep the implicit local_irq_{save / restore} call ?
> > 
> > It may not be needed but it will help avoiding any unexpected regression
> > report pointing at the NETDEV_TX_LOCKED removal change.
> 
> I thought about that but it doesn't prevent the irq handler from
> running on another CPU, so leaving it around seemed like cargo culting
> to me...

I don't mind removing it in a different patch at all. I'd rather see
the commit history underline that it's unrelated to whatever
NETDEV_TX_LOCKED / LLTX change.

> I don't have an atl1c, but the atl1e in my laptop seems to work fine
> with the (similar) change.
> 
> If you disagree I can respin with local_irq_save of course, but, if
> 'playing it safe' is main goal then its simpler to convert
> spin_trylock_irqsave to spin_lock_irqsave.

Your call, really.

-- 
Ueimor

Re: [PATCH net-next 2/6] atl1c: remove private tx lock

[Francois Romieu]

Florian Westphal  :
> Francois Romieu  wrote:
[...]
> > Play it safe and keep the implicit local_irq_{save / restore} call ?
> > 
> > It may not be needed but it will help avoiding any unexpected regression
> > report pointing at the NETDEV_TX_LOCKED removal change.
> 
> I thought about that but it doesn't prevent the irq handler from
> running on another CPU, so leaving it around seemed like cargo culting
> to me...

I don't mind removing it in a different patch at all. I'd rather see
the commit history underline that it's unrelated to whatever
NETDEV_TX_LOCKED / LLTX change.

> I don't have an atl1c, but the atl1e in my laptop seems to work fine
> with the (similar) change.
> 
> If you disagree I can respin with local_irq_save of course, but, if
> 'playing it safe' is main goal then its simpler to convert
> spin_trylock_irqsave to spin_lock_irqsave.

Your call, really.

-- 
Ueimor

Re: [PATCH net-next 2/6] atl1c: remove private tx lock

[Francois Romieu]

Florian Westphal  :
[...]
> diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c 
> b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> index d0084d4..a3200ea 100644
> --- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> +++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
[...]
> @@ -2217,16 +2215,10 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff 
> *skb,
>   }
>  
>   tpd_req = atl1c_cal_tpd_req(skb);
> - if (!spin_trylock_irqsave(>tx_lock, flags)) {
> - if (netif_msg_pktdata(adapter))
> - dev_info(>pdev->dev, "tx locked\n");
> - return NETDEV_TX_LOCKED;
> - }
>  
>   if (atl1c_tpd_avail(adapter, type) < tpd_req) {
>   /* no enough descriptor, just stop queue */
>   netif_stop_queue(netdev);
> - spin_unlock_irqrestore(>tx_lock, flags);
>   return NETDEV_TX_BUSY;
>   }
>

Play it safe and keep the implicit local_irq_{save / restore} call ?

It may not be needed but it will help avoiding any unexpected regression
report pointing at the NETDEV_TX_LOCKED removal change.

-- 
Ueimor

Re: [PATCH net-next 2/6] atl1c: remove private tx lock

[Francois Romieu]

Florian Westphal  :
[...]
> diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c 
> b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> index d0084d4..a3200ea 100644
> --- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> +++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
[...]
> @@ -2217,16 +2215,10 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff 
> *skb,
>   }
>  
>   tpd_req = atl1c_cal_tpd_req(skb);
> - if (!spin_trylock_irqsave(>tx_lock, flags)) {
> - if (netif_msg_pktdata(adapter))
> - dev_info(>pdev->dev, "tx locked\n");
> - return NETDEV_TX_LOCKED;
> - }
>  
>   if (atl1c_tpd_avail(adapter, type) < tpd_req) {
>   /* no enough descriptor, just stop queue */
>   netif_stop_queue(netdev);
> - spin_unlock_irqrestore(>tx_lock, flags);
>   return NETDEV_TX_BUSY;
>   }
>

Play it safe and keep the implicit local_irq_{save / restore} call ?

It may not be needed but it will help avoiding any unexpected regression
report pointing at the NETDEV_TX_LOCKED removal change.

-- 
Ueimor

Re: [PATCH net-next 2/6] atl1c: remove private tx lock

[Florian Westphal]

Francois Romieu  wrote:
> Florian Westphal  :
> [...]
> > diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c 
> > b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> > index d0084d4..a3200ea 100644
> > --- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> > +++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> [...]
> > @@ -2217,16 +2215,10 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff 
> > *skb,
> > }
> >  
> > tpd_req = atl1c_cal_tpd_req(skb);
> > -   if (!spin_trylock_irqsave(>tx_lock, flags)) {
> > -   if (netif_msg_pktdata(adapter))
> > -   dev_info(>pdev->dev, "tx locked\n");
> > -   return NETDEV_TX_LOCKED;
> > -   }
> >  
> > if (atl1c_tpd_avail(adapter, type) < tpd_req) {
> > /* no enough descriptor, just stop queue */
> > netif_stop_queue(netdev);
> > -   spin_unlock_irqrestore(>tx_lock, flags);
> > return NETDEV_TX_BUSY;
> > }
> >
> 
> Play it safe and keep the implicit local_irq_{save / restore} call ?
> 
> It may not be needed but it will help avoiding any unexpected regression
> report pointing at the NETDEV_TX_LOCKED removal change.

I thought about that but it doesn't prevent the irq handler from
running on another CPU, so leaving it around seemed like cargo culting
to me...

I don't have an atl1c, but the atl1e in my laptop seems to work fine
with the (similar) change.

If you disagree I can respin with local_irq_save of course, but, if
'playing it safe' is main goal then its simpler to convert
spin_trylock_irqsave to spin_lock_irqsave.

Re: [PATCH net-next 2/6] atl1c: remove private tx lock

[Florian Westphal]

Francois Romieu  wrote:
> Florian Westphal  :
> [...]
> > diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c 
> > b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> > index d0084d4..a3200ea 100644
> > --- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> > +++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
> [...]
> > @@ -2217,16 +2215,10 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff 
> > *skb,
> > }
> >  
> > tpd_req = atl1c_cal_tpd_req(skb);
> > -   if (!spin_trylock_irqsave(>tx_lock, flags)) {
> > -   if (netif_msg_pktdata(adapter))
> > -   dev_info(>pdev->dev, "tx locked\n");
> > -   return NETDEV_TX_LOCKED;
> > -   }
> >  
> > if (atl1c_tpd_avail(adapter, type) < tpd_req) {
> > /* no enough descriptor, just stop queue */
> > netif_stop_queue(netdev);
> > -   spin_unlock_irqrestore(>tx_lock, flags);
> > return NETDEV_TX_BUSY;
> > }
> >
> 
> Play it safe and keep the implicit local_irq_{save / restore} call ?
> 
> It may not be needed but it will help avoiding any unexpected regression
> report pointing at the NETDEV_TX_LOCKED removal change.

I thought about that but it doesn't prevent the irq handler from
running on another CPU, so leaving it around seemed like cargo culting
to me...

I don't have an atl1c, but the atl1e in my laptop seems to work fine
with the (similar) change.

If you disagree I can respin with local_irq_save of course, but, if
'playing it safe' is main goal then its simpler to convert
spin_trylock_irqsave to spin_lock_irqsave.