Re: [RFC PATCH v2 05/11] ACPI: platform: setup MSI domain for ACPI based platform device

[Hanjun Guo]

On 2016/9/15 23:18, Marc Zyngier wrote:
> On 15/09/16 15:05, Hanjun Guo wrote:
> > Hi Marc,
[...]
> > > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> > > > index 6482d47..ea01a37 100644
> > > > --- a/drivers/base/platform.c
> > > > +++ b/drivers/base/platform.c
> > > > @@ -24,6 +24,7 @@
> > > >   #include <linux/pm_domain.h>
> > > >   #include <linux/idr.h>
> > > >   #include <linux/acpi.h>
> > > > +#include <linux/msi.h>
> > > >   #include <linux/clk/clk-conf.h>
> > > >   #include <linux/limits.h>
> > > >   #include <linux/property.h>
> > > > @@ -500,6 +501,7 @@ struct platform_device *platform_device_register_full(
> > > >   	pdev->dev.parent = pdevinfo->parent;
> > > >   	pdev->dev.fwnode = pdevinfo->fwnode;
> > > >
> > > > +	acpi_configure_msi_domain(&pdev->dev);
> > >
> > > It feels odd to put this in the generic code, while you could perfectly
> > > put the call into acpi_platform.c and keep the firmware stuff away from
> > > the generic code.
> >
> > My feeling is the same, I'm still trying to find a new way to do it,
> > but I can't simply put that in acpi_platform.c, because
> >
> > acpi_create_platform_device()
> >     platform_device_register_full()
> > 	platform_device_alloc()  --> dev is alloced
> >          ...
> >          dev.fwnode  is set
> > 	(I get the msi domain by the fwnode in acpi_configure_msi_domain)
> >          ...
> >          platform_device_add()  --> which the device is probed.
> >
> > For devices like irqchip which needs the dev->msi_domain to be
> > set before it's really probed, because it needs the msi domain
> > to be the parent domain.
> >
> > If I call the function in acpi_create_platform_device() before
> > platform_device_register_full(), we just can't set dev's msi
> > domain, but if call it after platform_device_register_full(),
> > the irqchip like mbigen will not get its parent domain...
> >
> > DT is using another API for platform device probe, so has no
> > problems like I said above, any suggestions to do it right in
> > ACPI?
>
> How about having something that's completely generic and solves
> the problem once and for all? Something like this:
>
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index 6482d47..6f0f90b 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -533,6 +533,9 @@ struct platform_device *platform_device_register_full(
>  			goto err;
>  	}
>
> +	if (pdevinfo->pre_add_cb)
> +		pdevinfo->pre_add_cb(&pdev->dev);
> +
>  	ret = platform_device_add(pdev);
>  	if (ret) {
>  err:
> diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
> index 98c2a7c..44ea133 100644
> --- a/include/linux/platform_device.h
> +++ b/include/linux/platform_device.h
> @@ -74,6 +74,7 @@ struct platform_device_info {
>  		u64 dma_mask;
>
>  		struct property_entry *properties;
> +		void (*pre_add_cb)(struct device *);
>  };
>  extern struct platform_device *platform_device_register_full(
>  		const struct platform_device_info *pdevinfo);
>
> Plug pre_add_cb with your ACPI callback where you can do all the
> processing you want before the device is actually added.

Great, will do, thank you very much!

Hanjun