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SubjectRe: [PATCH 13/18] rpmsg: glink: Add rx done command
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Hi,
>> +    /* Take it off the tree of receive intents */
>> +    if (!intent->reuse) {
>> +        spin_lock(&channel->intent_lock);
>> +        idr_remove(&channel->liids, intent->id);
>> +        spin_unlock(&channel->intent_lock);
>> +    }
>> +
>> +    /* Schedule the sending of a rx_done indication */
>> +    spin_lock(&channel->intent_lock);
>> +    list_add_tail(&intent->node, &channel->done_intents);
>> +    spin_unlock(&channel->intent_lock);
>> +
>> +    schedule_work(&channel->intent_work);
>
> Adding one more parallel path will hit performance, if this worker could not get CPU cycles
> or blocked by other RT or HIGH_PRIO worker on global worker pool.
The idea is, by design to have parallel non-blocking paths for rx and tx (that is done as a
part of rx by sending the rx_done command), otherwise trying to send the rx_done
command in the rx isr context is a problem since the tx can wait for the FIFO space and
in worst case, can even lead to a potential deadlock if both the local and remote try
the same. Having said that, instead of queuing this work in to the global queue, this
can be put in to a local glink edge owned queue (or) a threaded isr ?, downstream does the
rx_done in a client specific worker.

Regards,
Sricharan

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