On 12/17/23 5:34 PM, claudiu beznea wrote:
[...]
>>> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>>>
>>> Do not apply the RX CSUM settings to hardware if the interface is down. In
>>> case runtime PM is enabled, and while the interface is down, the IP will be
>>> in reset mode (as for some platforms disabling/enabling the clocks will
>>> switch the IP to standby mode, which will lead to losing registers'
>>
>> To/From perhaps?
>> And just "register".
>>
>>> content) and applying settings in reset mode is not an option. Instead,
>>> cache the RX CSUM settings and apply them in ravb_open().
>>
>> Have this issue actually occurred for you?
>
> Setting RX CSUM while the if is down? No.
>
>>> Commit prepares for the addition of runtime PM.
>>>
>>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>> [...]
>>
>>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>>> index 633346b6cd7c..9ff943dff522 100644
>>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>>> @@ -1868,6 +1868,15 @@ static int ravb_open(struct net_device *ndev)
>>> if (info->gptp || info->ccc_gac)
>>> ravb_ptp_init(ndev, priv->pdev);
>>>
>>> + /* Apply features that might have been changed while the interface
>>> + * was down.
>>> + */
>>> + if (ndev->hw_features & NETIF_F_RXCSUM) {
>>
>> I'm afraid this is a wrong field; we need ndev->features, no?
>
> RX CSUM is not enabled for all ravb aware devices (see struct
> ravb_hw_info::net_hw_features). We should be setting the ECMR only for
> these ones. ravb_hw_info::net_hw_features is set in ndev->hw_features in
> probe(). So here code checks if platforms supports RXCSUM and then below it
> applies what has been requested though ndo_set_features(), if any.
OK. But we don't need this snippet here anyway...
>>> + u32 val = (ndev->features & NETIF_F_RXCSUM) ? ECMR_RCSC : 0;
>>> +
>>> + ravb_modify(ndev, ECMR, ECMR_RCSC, val);
>>> + }
>>> +
>>
>> The ECMR setting is already done in ravb_emac_init_rcar(), no need
>> to duplicate it here, I think...
>
> Ok, it worth being moved there.
No need to move, it's already there...
[...]
>>> @@ -2337,6 +2346,9 @@ static void ravb_set_rx_csum(struct net_device *ndev, bool enable)
>>> struct ravb_private *priv = netdev_priv(ndev);
>>> unsigned long flags;
>>>
>>> + if (!netif_running(ndev))
>>
>> Racy as well...
>
> It's also called with rtnl_mutex locked.
Well, at least the only place that calls the ndo_set_features()
method, __netdev_update_features() calls ASSERT_RTNL() at the start.
However, since we'd have to use the is_opened flag anyway, let's rely
on it instead...
[...]
MBR, Sergey
