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Subject: Re: [PATCH] net: can: Increase tx queue length
To:     Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com>,
        wg@grandegger.com, mkl@pengutronix.de, davem@davemloft.net
Cc:     linux-can@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <1552140446-31535-1-git-send-email-appana.durga.rao@xilinx.com>
From:   Andre Naujoks <nautsch2@gmail.com>
Message-ID: <cd71079c-664f-b1b6-bb21-ecda639ecbed@gmail.com>
Date:   Sat, 9 Mar 2019 15:22:00 +0100
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On 3/9/19 3:07 PM, Appana Durga Kedareswara rao wrote:
> While stress testing the CAN interface on xilinx axi can
> in loopback mode getting message "write: no buffer space available"
> Increasing device tx queue length resolved the above mentioned issue.

No need to patch the kernel:

$ ip link set <dev-name> txqueuelen 500

does the same thing.

> 
> Signed-off-by: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com>
> ---
> --> Network devices default tx_queue_len is 1000 but for socket
> can device it is 10 any reason for it?? 
>  
>  drivers/net/can/dev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
> index c05e4d5..32bd5be 100644
> --- a/drivers/net/can/dev.c
> +++ b/drivers/net/can/dev.c
> @@ -642,7 +642,7 @@ static void can_setup(struct net_device *dev)
>  	dev->mtu = CAN_MTU;
>  	dev->hard_header_len = 0;
>  	dev->addr_len = 0;
> -	dev->tx_queue_len = 10;
> +	dev->tx_queue_len = 500;
>  
>  	/* New-style flags. */
>  	dev->flags = IFF_NOARP;
>