Re: [PATCH v3 net-next 01/11] net: stmmac: prepare dma op mode config for multiple queues

From: Andy Shevchenko
Date: Mon May 08 2017 - 07:34:32 EST


On Mon, May 8, 2017 at 1:42 PM, Joao Pinto <Joao.Pinto@xxxxxxxxxxxx> wrote:
> Ãs 11:12 AM de 5/8/2017, Andy Shevchenko escreveu:
>> On Mon, May 8, 2017 at 12:54 PM, Joao Pinto <Joao.Pinto@xxxxxxxxxxxx> wrote:
>>> Ãs 10:36 AM de 5/8/2017, Andy Shevchenko escreveu:

>>>> JFYI: With today's linux-next when _kexec:ed_ kernel boots I tried and
>>>> got the following:

>>> Are you using the same version of Ethernet IP, 10/100?
>>
>> I'm running on Intel Galileo Gen2 board (v4.11 by the way works fine
>> with direct boot from SD card)
>>
>>> Could you please verify if the crash you are experiencing is this place?
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__git.kernel.org_pub_scm_linux_kernel_git_torvalds_linux.git_tree_drivers_net_ethernet_stmicro_stmmac_stmmac-5Fmain.c-23n2956&d=DwIFaQ&c=DPL6_X_6JkXFx7AXWqB0tg&r=s2fO0hii0OGNOv9qQy_HRXy-xAJUD1NNoEcc3io_kx0&m=UF269QZ9ExFRw1XXpgdvO2QeTCLEp-GquRe8OqZwRf0&s=yZu3uME5PK-3nJlxz-H-HfHh3Shjzg0je5If_jSXVb4&e=
>>>
>>> I would say that for rather old IPs, the napi is not capable of giving a valid
>>> queue number. Could you please print the queue index returned by this line?
>>>
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__git.kernel.org_pub_scm_linux_kernel_git_torvalds_linux.git_tree_drivers_net_ethernet_stmicro_stmmac_stmmac-5Fmain.c-23n2948&d=DwIFaQ&c=DPL6_X_6JkXFx7AXWqB0tg&r=s2fO0hii0OGNOv9qQy_HRXy-xAJUD1NNoEcc3io_kx0&m=UF269QZ9ExFRw1XXpgdvO2QeTCLEp-GquRe8OqZwRf0&s=p_TgHODJum23I2N4AldR4oIaOPffSDpk9agmbRMQgoM&e=
>>
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> @@ -2953,7 +2953,9 @@ static netdev_tx_t stmmac_xmit(struct sk_buff
>> *skb, struct net_device *dev)
>> unsigned int enh_desc;
>> unsigned int des;
>>
>> + pr_info("%s <<< 1: priv %p, queue: %u\n", __func__, priv, queue);
>> tx_q = &priv->tx_queue[queue];
>> + pr_info("%s <<< 2: priv %p, queue: %u tx_q: %p\n", __func__,
>> priv, queue, tx_q);
>>
>>
>> [ 101.591040] stmmac_xmit <<< 1: priv cdd1c4c0, queue: 7
>> [ 101.596377] stmmac_xmit <<< 2: priv cdd1c4c0, queue: 7 tx_q: cdd1caac

> I assume that the queue index is always 7 right? By return 7, the napi interface
> 'thinks' that your setup is using 8 TX queues which I assume it is not and thats
> the problem causing your board to malfuntion.
>
> Could you please check the values of the 'real' tx and rx queues count in this line?
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c#n4107
>
> For default they are =1, so napi should be assuming 1RX and 1TX, and so you
> should be getting queue index =0 in reception and transmission.
>
> In terms of reception, could you print the queue index that stmmac_poll is using
> here:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c#n3468

+ pr_info("%s <<< %u\n", __func__, rx_q->queue_index);
work_done = stmmac_rx(priv, budget, rx_q->queue_index);
if (work_done < budget) {
napi_complete_done(napi, work_done);

/* Configure real RX and TX queues */
netif_set_real_num_rx_queues(ndev, priv->plat->rx_queues_to_use);
netif_set_real_num_tx_queues(ndev, priv->plat->tx_queues_to_use);
+ pr_info("%s <<< %hhu %hhu\n", __func__,
priv->plat->rx_queues_to_use, priv->plat->tx_queues_to_use);


[ 44.374161] stmmac_dvr_probe <<< 0 0

[ 109.014763] stmmac_xmit <<< 1: priv cdcea4c0, queue: 2
[ 109.020099] stmmac_xmit <<< 2: priv cdcea4c0, queue: 2 tx_q: cdcea9e4

That's all, no poll activated.

--
With Best Regards,
Andy Shevchenko