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

Christoph Hellwig
2017-08-31T10:23:24Z

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.