On Mon, 21 Apr 2014 08:47:41 -0500, Rob Herring <robherring2@xxxxxxxxx> wrote: > On Fri, Apr 18, 2014 at 6:24 PM, Tony Lindgren <tony@xxxxxxxxxxx> wrote: > > * Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> [140418 16:04]: > >> On Fri, Apr 18, 2014 at 02:58:48PM -0700, Tony Lindgren wrote: > >> > Oh come on, let's stop pretending it's not broken. And it's way worse with > >> > device tree as there's nothing making sure the resources for a driver > >> > are set up before the driver probes. And we've been unable to fix just > >> > this issue alone for about six months now. It's also broken beyond that. > >> > It's called of_platform_bus yet it won't even pass the platform_data > >> > as auxdata to the devices on a sub-bus instantatiated like I2C. > >> > >> Isn't there a much simpler solution to the platform device IRQ problem? > >> > >> Rather than trying to fix it at the point where the resources are > >> created, why not just *not* have DT create the IRQ resources in the > >> first place, and instead have platform_get_irq() (which is the function > >> which should be used to get an IRQ) be the actor to do whatever is > >> necessary to return the IRQ(s) ? > > > > Yeah why not. I don't see why we would need to do all this of_* special > > trickery for much anything beyond parsing the binding. > > That can work, but it will still need something like > of_find_irq_domain() to determine whether to return -EPROBE_DEFER or > not. > > You could also go in the other direction and don't create the device > until the resources can be resolved. Unlike any of the other > solutions, that would work for amba bus as well although we may never > have a case where we need this with the amba bus. This would require > making of_platform_populate be callable multiple times, but there are > already some other reasons for wanting to do that. Specifically, I > would like the core code to call of_platform_populate with default > options and then only platforms with non-default options need a call > to of_platform_populate. No it wouldn't. It would require of_platform_populate to do the right thing internally and know when to create devices from nodes that get flagged by calling of_platform_populate(). > >> Yes, I know we have some drivers which use platform_get_resources() with > >> IORESOURCE_IRQ, but they should really use the right accessor. And those > >> who just dereference the resource array directly... get what's coming > >> (though of course they have to be fixed.) > > > > $ git grep IORESOURCE_IRQ drivers/ | grep platform_get_resource | wc -l > > 179 > > Certainly, this is worthwhile clean-up no matter what the solution. Yes, and it works no matter what the data source is; platform_data, dt, acpi, and works on any platform. g. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
