Re: Re: [PATCH 2/3 v8] mailbox: Enable BCM2835 mailbox support

From: Alexander Stein
Date: Fri May 08 2015 - 04:34:59 EST


On Thursday 07 May 2015, 12:54:20 wrote Eric Anholt:
> Noralf TrÃnnes <noralf@xxxxxxxxxxx> writes:
>
> > Den 05.05.2015 22:27, skrev Eric Anholt:
> >> From: Lubomir Rintel <lkundrak@xxxxx>
> >>
> >> This mailbox driver provides a single mailbox channel to write 32-bit
> >> values to the VPU and get a 32-bit response. The Raspberry Pi
> >> firmware uses this mailbox channel to implement firmware calls, while
> >> Roku 2 (despite being derived from the same firmware tree) doesn't.
> >>
> >> The driver was originally submitted by Lubomir, based on the
> >> out-of-tree 2708 mailbox driver. Eric Anholt fixed it up for
> >> upstreaming, with the major functional change being that it now has no
> >> notion of multiple channels (since that is a firmware-dependent
> >> concept) and instead the raspberrypi-firmware driver will do that
> >> bit-twiddling in its own messages.
> > ...
> >> +static struct platform_driver bcm2835_mbox_driver = {
> >> + .driver = {
> >> + .name = "bcm2835-mbox",
> >> + .owner = THIS_MODULE,
> >> + .of_match_table = bcm2835_mbox_of_match,
> >> + },
> >> + .probe = bcm2835_mbox_probe,
> >> + .remove = bcm2835_mbox_remove,
> >> +};
> >> +module_platform_driver(bcm2835_mbox_driver);
> >
> > I have tested this driver and the firmware driver booting directly
> > from the VideoCore bootloader (no uboot).
> > The mailbox driver loads too late to turn on USB power:
>
> Yeah, I have a patch on my branches that returns -EPROBE_DEFER when
> trying to get a power domain and not finding the provider. It was
> rejected by the maintainers in favor of a proposed solution whose
> description I didn't quite follow.

Do you have a link for this thread?

> > This silences the warning:
> > struct raspberrypi_power_domain raspberrypi_power_domain_usb = {
> > .base = {
> > .power_on_latency_ns = 600000000,
>
> Oh, nice. Thanks!

Well, Using a timeout for dependencies seems odd to me.

Regards,
Alexander

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