Re: [PATCH 2/2] mmc: core: Turn mmc_alloc|free_host() into static functions

[Ulf Hansson]

On Wed, Sep 16, 2026 at 9:43 AM Johan Hovold <johan@xxxxxxxxxx> wrote:
>
> On Tue, Sep 15, 2026 at 03:20:46PM +0200, Ulf Hansson wrote:
> > From: Ulf Hansson <ulfh@xxxxxxxxxx>
> >
> > As there are no longer any users of these functions, let's make them
> > internal to the mmc core.
>
> Why would you want to do that? The devres helpers should just be simple
> wrappers around these and sometimes devres just isn't a good fit.

At the moment there seems to be no need for them. I would rather keep
API/interfaces as simple as possible, so I prefer to remove them at
this point.

If we see a need for them, we can always add them back.

>
> Especially with the work cancellations present in mmc_free_host() (which
> I have pointed out elsewhere should not be there), a driver may need to
> free the host before tearing down other non-devres managed resources
> during unbind.

Can you please point me to such an example so I can try to understand better?

>
> This may even be needed for greybus which currently destroys the
> connection before freeing the host.

I looked closer at gb_sdio_remove() (the greybus sdio driver's
->remove() callback) and I think the problem isn't about freeing the
host.

Instead it seems like the call to mmc_remove_host() is done too late.
To me it looks like when the mmc core tries to power off the card
gracefully, through mmc_remove_host() the driver has already moved
into a state where it no longer accepts any requests.

>
> I suggest you just keep the non-devres interface around (after updating
> the prototype).
>
> > While at it, let's also flip the order of the
> > in-parameters to mmc_alloc_host() to be consistent with devm_alloc_host().
>
> Johan

Kind regards
Uffe