Re: [PATCH v2] wait while adding MMC host to ensure root mounts

From: Chris Ball
Date: Wed Mar 27 2013 - 07:57:45 EST


Hi,

On Wed, Mar 27 2013, Ulf Hansson wrote:
> I noticed you merged this. I thought the idea was to use the rootwait
> or rootdelay?

That's necessary before the patch, but it would be better if we didn't
have to pass rootwait, all else being equal.

> Moreover, this patch will have bad impact on booting the kernel, since
> every host device that has scheduled a detect work from it's probe
> function will also wait for it to finish. Even if it is the boot
> device of not. If this is needed, I would prefer that a host cap is
> used.

I see, you're worried about a performance regression where every boot
takes longer than it used to while MMC quiesces. That's fair. Do you
think you could tell me how much delay this adds to a boot for you, so
that we can consider whether the usability improvement is worth it?

If the delay's significant, I agree with you and will revert this patch.

Thanks,

- Chris.
--
Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
One Laptop Per Child
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