Re: [PATCH v4 1/2] crypto: engine - support for parallel requests

[Horia GeantÄ]

On 3/12/2020 5:26 AM, Herbert Xu wrote:
> On Mon, Mar 09, 2020 at 12:51:32AM +0200, Iuliana Prodan wrote:
>>
>>  	ret = enginectx->op.do_one_request(engine, async_req);
>> -	if (ret) {
>> -		dev_err(engine->dev, "Failed to do one request from queue: %d\n", ret);
>> -		goto req_err;
>> +	can_enq_more = ret;
>> +	if (can_enq_more < 0) {
>> +		dev_err(engine->dev, "Failed to do one request from queue: %d\n",
>> +			ret);
>> +		goto req_err_1;
>> +	}
> 
> So this now includes the case of the hardware queue being full
> and the request needs to be queued until space opens up again.
I see no difference when compared with existing implementation:
in both cases failing the transfer from SW queue to HW queue means
losing the request irrespective of the error code returned by .do_one_request.

This doesn't mean it shouldn't be fixed.

> In this case, we should not do dev_err.  So you need to be able
> to distinguish between the hardware queue being full vs. a real
> fatal error on the request (e.g., out-of-memory or some hardware
> failure).
> 
Yes, in case of -ENOSPC (HW queue full) the request should be put back
in the SW queue.

Thanks,
Horia