Re: [PATCH 13/13] bcm2835_cprman: put some peripherals of bcm2835 cprman into the 'misc' category

[Markus Armbruster]

Peter Maydell <peter.maydell@linaro.org> writes:

> On Mon, 16 Nov 2020 at 17:09, Markus Armbruster <armbru@redhat.com> wrote:
>> But TYPE_CPRMAN_PLL is *not* a descendant of TYPE_SYS_BUS_DEVICE, it's a
>> bus-less device:
>>
>>     static const TypeInfo cprman_pll_info = {
>>         .name = TYPE_CPRMAN_PLL,
>> --->    .parent = TYPE_DEVICE,
>>         .instance_size = sizeof(CprmanPllState),
>>         .class_init = pll_class_init,
>>         .instance_init = pll_init,
>>     };
>
> I'm really dubious of devices that directly inherit from
> TYPE_DEVICE, because their reset method won't be automatically
> called. In this case it looks like the TYPE_BCM2835_CPRMAN
> device's reset method manually calls reset on these devices,
> though, so it isn't actually buggy, just confusing.

I guess this is a trap for unwary implementers, aggravated by our usual
dearth of qdev documentation.  I can see ~100 .parent = TYPE_DEVICE
lines.  Checking them all manually won't be fun.  Any automation ideas?

The concept "bus-less device" is sane.  We used not to have it, and the
resulting need for pseudo-busses was annoying enough to make us add
bus-less devices.