Subject: Re: Gianfar driver failing on MPC8641D based board

From: Martyn Welch <[email-masked]>
Date: Fri, 26 Feb 2010 12:06:15 +0000

Anton Vorontsov wrote:
> On Thu, Feb 25, 2010 at 07:53:30PM -0500, Paul Gortmaker wrote:
> [...]
>   
>> I was able to reproduce it on an 8641D and bisected it down to this:
>>
>> -----------
>> commit a3bc1f11e9b867a4f49505ecac486a33af248b2e
>> Author: Anton Vorontsov <[email-masked]>
>> Date:   Tue Nov 10 14:11:10 2009 +0000
>>
>>     gianfar: Revive SKB recycling
>>     
>
> Thanks for the bisect. I have a guess why tx hangs in
> SMP case. Could anyone try the patch down below?
>   

Yup, no problem. I'm afraid it doesn't resolve the problem for me.

> [...]
>   
>> ...which probably explains why you weren't seeing it on non-SMP.
>> I'd imagine it would show up on any of the e500mc boards too.
>>     
>
> Yeah.. Pity, I don't have SMP boards anymore. I'll try
> to get one though.
>
>
> diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
> index 8bd3c9f..3ff3bd0 100644
> --- a/drivers/net/gianfar.c
> +++ b/drivers/net/gianfar.c
> @@ -2614,6 +2614,8 @@ static int gfar_poll(struct napi_struct *napi, int budget)
>  			tx_queue = priv->tx_queue[rx_queue->qindex];
>  
>  			tx_cleaned += gfar_clean_tx_ring(tx_queue);
> +			if (!tx_cleaned && !tx_queue->num_txbdfree)
> +				tx_cleaned += 1; /* don't complete napi */
>  			rx_cleaned_per_queue = gfar_clean_rx_ring(rx_queue,
>  							budget_per_queue);
>  			rx_cleaned += rx_cleaned_per_queue;
>   

-- 
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