[PATCH] vchiq driver

[Stefan Wahren]

Hi Steven,

Am 12.08.22 um 22:57 schrieb Steven A. Falco:
> On 8/12/22 04:31 PM, Stefan Wahren wrote:
>> Hi Steven,
>>
>> Am 12.08.22 um 19:13 schrieb Steven A. Falco:
>>> I am using Fedora Linux on a Raspberry Pi 4B.  When I use the 
>>> kernel-provided device tree, I have a /dev/vchiq node, but if I 
>>> instead use the firmware-provided device tree, this node is not 
>>> created.
>> not sure which kernel is meant, but it's not the mainline kernel.
>
> I'm running Fedora Rawhide, which has kernel 5.19.0-65.fc37.aarch64.  
> I thought that kernel was current, but I can see that I was wrong. :-)

sorry, i was wrong. I checked this. The wrong vchiq compatible is 
accidentally enabled on the Raspberry Pi 4 & Co. Thanks for reporting 
this issue

         mailbox at 7e00b840 {
             compatible = "brcm,bcm2835-vchiq";
             reg = <0x7e00b840 0x3c>;
             interrupts = <0x00 0x22 0x04>;
         };

@Florian, @Arnd

What do you think about how to handle this? The vchiq driver is in 
staging and Greg is not very happy about new features like bcm2711 
support until the TODOs are finished.

Replacing the compatible with the proper one would fix the device tree, 
but would stop probing of the driver for the few brave mainline users 
(regression from user point of view).

Should we add "brcm,bcm2711-vchiq" to compatibles even the driver 
doesn't supported it yet or better keep as it is?

Best regards