Re: [PATCH V5 11/13] mmc: block: Add CQE support

Adrian Hunter
2017-08-31T12:07:03Z

On 31/08/17 13:23, Christoph Hellwig wrote:
> On Sun, Aug 20, 2017 at 02:13:03PM +0200, Linus Walleij wrote:
>> So adding a new (in effect) invasive block driver needs to at least
>> be CC:ed to the block maintainers so we don't sneak anything like
>> that in under the radar.
>
> Yes.
>
>> And this semaphoring and threading is just as confusing as ever and now
>> we have two of them. (Sorry, I'm grumpy.)
>
> But your are grumpy for a good reason. The MMC driver is a pain
> to understand for even a seasons block layer developer.
>
>> What we need is an MMC stack where it is clear where blocks come in
>> and out and how they are processed by the block layer, but now we
>> already have a scary Rube Goldberg-machine and it is not getting better.
>> If people have different feelings they can tell me off right now.
>
> Agreed.
>
>>
>> I have my hopes up that we can get the code lesser and more readable
>> with MQ, as I tried to illustrate in my attempts, which are indeed lame
>> because they don't work because of misc and SDIO use cases, but
>> I'm honestly doing my best. Currently with other clean-ups to get a
>> clean surface to do that.
>>
>> As it stands, the MQ migration work size is in some spots doubled or
>> more than doubled after this commit :(
>
> I don't think we should merge this.
>

OK, let's merge the blk-mq version then. Here it is in V7: