[PATCH v3 16/16] arm_mpam: detect and enable MPAM-Fb PCC support

Andre Przywara andre.przywara at arm.com
Tue Jul 21 07:54:38 PDT 2026


Hi Niyas,

On 7/14/26 14:32, Niyas Sait wrote:
> On 10/07/2026 15:45, Andre Przywara wrote:
>> +    cur->pcc_cl.dev = dev;
>> +    cur->pcc_cl.rx_callback = mpam_pcc_rx_callback;
>> +    cur->pcc_cl.tx_block = true;
>> +    cur->pcc_cl.tx_tout = 1000; /* 1s */
> 
> Should this timeout be based on nominal latency reported in PCC table 
> instead of being hard coded to 1s here? May be some multiple of nominal 
> latency reported

I originally thought that this would be handled by the PCC code, but 
that just parses the value, and puts it in the pcc_mbox_chan struct. 
Which we only get access to *after* we request the channel in the next 
line here.
But it's only mbox_send_message() that uses the value, so I think we can 
populate that value later on still. And yeah, some multiple of the 
nominal latency sounds reasonable.

Cheers,
Andre




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