Re: [net,PATCH] net: ks8851: Reinstate disabling of BHs around IRQ handler

Marek Vasut
2026-04-08T21:21:20Z

On 4/8/26 9:15 PM, Nicolai Buchwitz wrote:
> On 8.4.2026 17:41, Marek Vasut wrote:
>> On 4/8/26 12:54 PM, Nicolai Buchwitz wrote:
>>
>> Hello Nicolai,
>>
>> thank you for testing on the SPI variant, that helped a lot.
>>
>>> In order to make this work I would propose something like this (which
>>> works in my SPI setup):
>>>
>>> --- a/drivers/net/ethernet/micrel/ks8851_par.c
>>> +++ b/drivers/net/ethernet/micrel/ks8851_par.c
>>> @@ -60,12 +60,14 @@ static void ks8851_lock_par(struct ks8851_net
>>> *ks, unsigned long *flags)
>>>   {
>>>       struct ks8851_net_par *ksp = to_ks8851_par(ks);
>>>
>>> +    local_bh_disable();
>>>       spin_lock_irqsave(&ksp->lock, *flags);
>>>   }
>>>
>>>   static void ks8851_unlock_par(struct ks8851_net *ks, unsigned long
>>> *flags)
>>>   {
>>>       struct ks8851_net_par *ksp = to_ks8851_par(ks);
>>>
>>>       spin_unlock_irqrestore(&ksp->lock, *flags);
>>> +    local_bh_enable();
>>>   }
>>>
>>> Tested-by: Nicolai Buchwitz <nb@tipi-net.de>  # KS8851 SPI, non-RT
>>> (regression + proposed fix)
>>
>> Are you also able to test the KS8851 driver with PREEMPT_RT enabled
>> and heavy iperf3 traffic on the SPI variant ? Does that trigger any
>> issues ? I ran 'iperf3 -s' on the KS8851 end and 'iperf3 -c
>> 192.168.1.300 -t 0 --bidir' on the host PC side.
>
> Successfully tested with both PREEMPT_RT and non-RT kernels using the
> iperf3 command above - no issues observed. Both builds included the fix
> from my previous message.
> If there is anything else worth testing on the KS8851 SPI variant,
> please let me know.
Thank you for that. Could you please add the TB to v2 too ?