Re: [PATCH V13 04/10] mmc: block: Add CQE support

From: Linus Walleij
Date: Thu Nov 09 2017 - 07:04:49 EST


On Wed, Nov 8, 2017 at 2:20 PM, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> On 08/11/17 11:00, Linus Walleij wrote:

>> This and other bits gives me the feeling CQE is now actually ONLY
>> working on the MQ path.
>
> I was not allowed to support non-mq.

Fair enough.

>> That is good. We only add new functionality on the MQ path,
>> yay!
>>
>> But this fact (only abailable iff MQ==true) should at least be
>> mentioned in the commit message I think?
>
> Why? CQE is MQ only.

So if you read what I say, I think the commit message should
say that CQE is MQ only so that people know that CQE is
MQ only.

>> So why not ditch the old block layer or at least make MQ default?
>
> CQE is MQ only.

Yeah? So why keep it around for everything else?

>> When you keep it like this people have to reconfigure
>> their kernel to enable MQ before they see the benefits of MQ+CQE
>> combined, I think that should rather be the default experience.
>
> Not at all. I guess you are confusing the legacy mmc with CQE. CQE is not
> a layer on top of legacy mmc. It is an alternative to legacy mmc. CQE
> does not sit on top of the legacy mmc blk-mq support. You don't have to
> enable legacy mmc blk-mq support to use CQE.

Now I am confused. I can't parse the last sentence. There is no
such thing as legcay blk-mq?

Yours,
Linus Walleij