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

[Nicolai Buchwitz <nb@tipi-net.de>]

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.

> 
> Let me prepare a slightly updated fix and send a V2.

Regards
Nicolai