[WARNING] pxamci: 'pxa2xx-mci.0' does not have a release() function.

[Russell King - ARM Linux]

On Fri, Oct 23, 2009 at 11:50:28AM +0200, Antonio Ospite wrote:
> On Thu, 22 Oct 2009 23:57:58 +0100
> Russell King - ARM Linux <linux at arm.linux.org.uk> wrote:
> 
> > On Fri, Oct 23, 2009 at 12:36:31AM +0200, Antonio Ospite wrote:
> > > Hi,
> > > 
> > > I get this warning on shutdown. How to fix it properly?
> > > 
> > > FYI, in my setup pxa2xx_spi is the parent for pxamci, set using
> > > this patch:
> > > http://git.openezx.org/openezx.git?a=commitdiff;h=0ffd85ad8faea3456d4ecf5f63ae65aca26fff21
> > 
> > This sounds like it's the cause of the problem - from the backtrace, it
> > looks like SPI expects the children of the SPI device to be its own
> > responsibility to maintain.
> > 
> > Hence, because you've made pxamci a child of SPI, SPI is trying to
> > unregister and release the pxamci device.
> 
> A little more background: we need pxamci to be a child of SPI because
> our PMIC is connected via SPI, and a PMIC regulator is used for mmc
> powering; enforcing this hierarchy is needed to make pxamci suspend and
> resume properly.

I don't think this is the right solution - and I don't know what the
right solution would be given that the interfaces I suspect you need
aren't public.

I don't think you can reverse the order of SPI and MMC initialization
because that'd mean MMC could try to use SPI before it exists.

Maybe the right answer is for SPI to stop thinking it owns all child
devices, and only unregister devices which it owns (iow, are of some
SPI bus-type.)

Adding Greg for comment.

> The board init does:
> 	spi_pd = platform_device_alloc("pxa2xx-spi", 1);
> 	spi_pd->dev.platform_data = &ezx_spi_masterinfo;
> 	platform_device_add(spi_pd);
> 	spi_register_board_info(ARRAY_AND_SIZE(a780_spi_boardinfo));
> 
> 	pxa_set_mci_parent(&spi_pd->dev);
> 	pxa_set_mci_info(&ezx_mci_platform_data);
> 
> Now, do you suggest to adapt pxamci so it supports the case when
> another driver wants to release it? I am not sure how to do that, tho.

Definitely not.