* Re: [PATCH] platform/raspberrypi: vchiq: register bus at subsys_initcall
2026-10-13 13:14 ` [PATCH] platform/raspberrypi: vchiq: register bus at subsys_initcall Martin Wetterwald
@ 2026-10-13 16:27 ` Jai Luthra
2026-10-15 21:25 ` Gaston Gonzalez
1 sibling, 0 replies; 3+ messages in thread
From: Jai Luthra @ 2026-10-13 16:27 UTC (permalink / raw)
To: Florian Fainelli, Martin Wetterwald
Cc: Broadcom internal kernel review list, Greg Kroah-Hartman,
Stefan Wahren, Phil Elwell, Laurent Pinchart, Umang Jain,
Kees Cook, linux-rpi-kernel, linux-arm-kernel, linux-staging,
linux-kernel, regressions, Martin Wetterwald
Hi Martin,
Thanks for the quick fix.
Quoting Martin Wetterwald (2026-10-13 18:44:35)
> Since the VCHIQ interface was moved out of staging, its bus is no longer
> guaranteed to be registered before its client drivers. bcm2835-audio,
> still in drivers/staging, registers at device_initcall level and now
> runs first:
>
> Driver 'bcm2835-audio' was unable to register with bus_type
> 'vchiq-bus' because the bus was not initialized.
>
> Register the bus and the platform driver at subsys_initcall so the bus
> exists before any client driver, independently of link order. The
> platform driver probe already returns -EPROBE_DEFER while the firmware
> is not ready, so probing earlier is safe. When built as modules, this is
> equivalent to module_init() and nothing changes.
>
> Tested on Raspberry Pi 1B rev2, 1B+, 2B, 3B and 4B with VCHIQ and
> bcm2835-audio both builtin and both as modules.
>
> Fixes: aa125180c673 ("platform/raspberrypi: Destage VCHIQ interface")
> Reported-by: Martin Wetterwald <martin@wetterwald.eu>
> Link: https://lore.kernel.org/r/CAFERDQ0FpdVvA5VJxOyRAE_pgxnPVmFx1tkZio5R272j6Bs4tg@mail.gmail.com/
> Closes: https://lore.kernel.org/r/CAFERDQ0FpdVvA5VJxOyRAE_pgxnPVmFx1tkZio5R272j6Bs4tg@mail.gmail.com/
> Signed-off-by: Martin Wetterwald <martin@wetterwald.eu>
Reviewed-by: Jai Luthra <jai.luthra@ideasonboard.com>
Thanks,
Jai
> ---
> drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c b/drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c
> index e78641703252..d35f5ac5c2e2 100644
> --- a/drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c
> +++ b/drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c
> @@ -1462,7 +1462,7 @@ static int __init vchiq_driver_init(void)
>
> return ret;
> }
> -module_init(vchiq_driver_init);
> +subsys_initcall(vchiq_driver_init);
>
> static void __exit vchiq_driver_exit(void)
> {
> --
> 2.55.0
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] platform/raspberrypi: vchiq: register bus at subsys_initcall
2026-10-13 13:14 ` [PATCH] platform/raspberrypi: vchiq: register bus at subsys_initcall Martin Wetterwald
2026-10-13 16:27 ` Jai Luthra
@ 2026-10-15 21:25 ` Gaston Gonzalez
1 sibling, 0 replies; 3+ messages in thread
From: Gaston Gonzalez @ 2026-10-15 21:25 UTC (permalink / raw)
To: Martin Wetterwald, Florian Fainelli
Cc: Broadcom internal kernel review list, Jai Luthra,
Greg Kroah-Hartman, Stefan Wahren, Phil Elwell, Laurent Pinchart,
Umang Jain, Kees Cook, linux-rpi-kernel, linux-arm-kernel,
linux-staging, linux-kernel, regressions
On Tue Oct 13, 2026 at 10:14 AM -03, Martin Wetterwald wrote:
> Since the VCHIQ interface was moved out of staging, its bus is no longer
> guaranteed to be registered before its client drivers. bcm2835-audio,
> still in drivers/staging, registers at device_initcall level and now
> runs first:
>
> Driver 'bcm2835-audio' was unable to register with bus_type
> 'vchiq-bus' because the bus was not initialized.
>
> Register the bus and the platform driver at subsys_initcall so the bus
> exists before any client driver, independently of link order. The
> platform driver probe already returns -EPROBE_DEFER while the firmware
> is not ready, so probing earlier is safe. When built as modules, this is
> equivalent to module_init() and nothing changes.
>
> Tested on Raspberry Pi 1B rev2, 1B+, 2B, 3B and 4B with VCHIQ and
> bcm2835-audio both builtin and both as modules.
>
> Fixes: aa125180c673 ("platform/raspberrypi: Destage VCHIQ interface")
> Reported-by: Martin Wetterwald <martin@wetterwald.eu>
> Link: https://lore.kernel.org/r/CAFERDQ0FpdVvA5VJxOyRAE_pgxnPVmFx1tkZio5R272j6Bs4tg@mail.gmail.com/
> Closes: https://lore.kernel.org/r/CAFERDQ0FpdVvA5VJxOyRAE_pgxnPVmFx1tkZio5R272j6Bs4tg@mail.gmail.com/
> Signed-off-by: Martin Wetterwald <martin@wetterwald.eu>
> ---
> drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c b/drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c
> index e78641703252..d35f5ac5c2e2 100644
> --- a/drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c
> +++ b/drivers/platform/raspberrypi/vchiq-interface/vchiq_arm.c
> @@ -1462,7 +1462,7 @@ static int __init vchiq_driver_init(void)
>
> return ret;
> }
> -module_init(vchiq_driver_init);
> +subsys_initcall(vchiq_driver_init);
>
> static void __exit vchiq_driver_exit(void)
> {
Hi,
For Raspberry Pi Zero v1.3:
Tested-by: Gaston Gonzalez <gascoar@gmail.com>
Test setup:
- Branch: patch manually applied in staging-next over commit ec1ecf4f23c5
- Setup: RPi Zero v1.3 connected to a HDMI monitor
- OS: standard raspbian with the desktop environment enabled
- Driver built both as a module and built-in.
- The following command was run to test the sound: 'speaker-test -t wav -c 2'
- Result: Both HDMI audio channels worked correctly
I’d be happy to run any additional tests if needed.
Regards,
Gaston
^ permalink raw reply [flat|nested] 3+ messages in thread