Messages in this thread | | | Date | Fri, 08 May 2015 22:38:09 +0200 | From | Noralf Trønnes <> | Subject | Re: [PATCH 2/3 v8] mailbox: Enable BCM2835 mailbox support |
| |
Den 08.05.2015 10:33, skrev Alexander Stein: > On Thursday 07 May 2015, 12:54:20 wrote Eric Anholt: >> Noralf Trønnes <noralf@tronnes.org> writes: >> >>> Den 05.05.2015 22:27, skrev Eric Anholt: >>>> From: Lubomir Rintel <lkundrak@v3.sk> >>>> >>>> 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.
I can only find one place where power_on_latency_ns is set, arch/arm/mach-imx/gpc.c: static struct pu_domain imx6q_pu_domain = { .base = { .name = "PU", .power_off = imx6q_pm_pu_power_off, .power_on = imx6q_pm_pu_power_on, .power_off_latency_ns = 25000, .power_on_latency_ns = 2000000, }, };
power_on_latency_ns is not set by the core, so it defaults to zero. So in the default case, genpd_power_on() will always issue a warning on the first power on.
I would say that power_on_latency_ns is a characteristic of the power domain, like enable_time for regulators.
Noralf.
| |