udev and pci devices

udev and pci devices

[Holger Hans Peter Freyther]

Hi all,

we stumbled across an issue of udev and busybox/modprobe. udev detects a PCI
device and according to udevadm test it is selecting:

udev_rules_apply_to_event: RUN '/sbin/modprobe -bv $env{MODALIAS}'
/lib/udev/rules.d/80-drivers.rules:5
udev_rules_apply_to_event: RUN '/sbin/modprobe $env{MODALIAS}'
/etc/udev/rules.d/local.rules:31


but as the busybox modprobe does not support the 'b' option it just fails
before executing the other rules. There are some possible fixes to it.

1.)
  - remove the local.rules rule for loading the module
  - build busybox with CONFIG_FEATURE_MODPROBE_BLACKLIST for -b support

2.)
  - remove the 80-drivers.rules and let the modprobe just be executed by the
    other udev rules.

comments?

	holger

Re: udev and pci devices

[Richard Purdie]

On Fri, 2011-09-16 at 02:19 +0200, Holger Hans Peter Freyther wrote:
> Hi all,
> 
> we stumbled across an issue of udev and busybox/modprobe. udev detects a PCI
> device and according to udevadm test it is selecting:
> 
> udev_rules_apply_to_event: RUN '/sbin/modprobe -bv $env{MODALIAS}'
> /lib/udev/rules.d/80-drivers.rules:5
> udev_rules_apply_to_event: RUN '/sbin/modprobe $env{MODALIAS}'
> /etc/udev/rules.d/local.rules:31
> 
> 
> but as the busybox modprobe does not support the 'b' option it just fails
> before executing the other rules. There are some possible fixes to it.
> 
> 1.)
>   - remove the local.rules rule for loading the module
>   - build busybox with CONFIG_FEATURE_MODPROBE_BLACKLIST for -b support

This sounds like the correct thing to do I think since the
80-driver.rules file is coming from upstream, the local.rules piece is
our extras piece.

Cheers,

Richard

Re: udev and pci devices

[Holger Hans Peter Freyther]

On 09/16/2011 02:19 AM, Holger Hans Peter Freyther wrote:
> Hi all,
> 
> we stumbled across an issue of udev and busybox/modprobe. udev detects a PCI
> device and according to udevadm test it is selecting:

ping? any interest in having module loading for PCI devices working?

Re: udev and pci devices

[Holger Hans Peter Freyther]

On 10/01/2011 08:34 PM, Holger Hans Peter Freyther wrote:

> ping? any interest in having module loading for PCI devices working?

no interest?

Re: udev and pci devices

[Mark Hatle]

On 10/12/11 2:41 PM, Holger Hans Peter Freyther wrote:
> On 10/01/2011 08:34 PM, Holger Hans Peter Freyther wrote:
> 
>> ping? any interest in having module loading for PCI devices working?
> 
> no interest?

I think up to this point most of the udev support has focused on typical hotplug
items, specifically USB.

In my experience things like PCI devices are better setup statically based on
the system being created.  (Note, I'm not sure if we have an easy way to do that
at this point or not..)

--Mark

Re: udev and pci devices

[Khem Raj]

On Fri, Sep 16, 2011 at 5:35 AM, Richard Purdie
<richard.purdie@linuxfoundation.org> wrote:
> On Fri, 2011-09-16 at 02:19 +0200, Holger Hans Peter Freyther wrote:
>> Hi all,
>>
>> we stumbled across an issue of udev and busybox/modprobe. udev detects a PCI
>> device and according to udevadm test it is selecting:
>>
>> udev_rules_apply_to_event: RUN '/sbin/modprobe -bv $env{MODALIAS}'
>> /lib/udev/rules.d/80-drivers.rules:5
>> udev_rules_apply_to_event: RUN '/sbin/modprobe $env{MODALIAS}'
>> /etc/udev/rules.d/local.rules:31
>>
>>
>> but as the busybox modprobe does not support the 'b' option it just fails
>> before executing the other rules. There are some possible fixes to it.
>>
>> 1.)
>>   - remove the local.rules rule for loading the module
>>   - build busybox with CONFIG_FEATURE_MODPROBE_BLACKLIST for -b support
>
> This sounds like the correct thing to do I think since the
> 80-driver.rules file is coming from upstream, the local.rules piece is
> our extras piece.

Seems fine to me however
How much size does CONFIG_FEATURE_MODPROBE_BLACKLIST add to busybox
Is there some existing knob that could be used to enable/disable this feature
>
> Cheers,
>
> Richard
>
> _______________________________________________
> poky mailing list
> poky@yoctoproject.org
> https://lists.yoctoproject.org/listinfo/poky
>

Re: udev and pci devices

[Holger Hans Peter Freyther]

On 10/12/2011 09:47 PM, Mark Hatle wrote:

> In my experience things like PCI devices are better setup statically based on
> the system being created.  (Note, I'm not sure if we have an easy way to do that
> at this point or not..)

With statically you mean putting module_autoload_NAME = "name" in the out of
tree kernel module recipe? This will not 'scale' for us (e.g. one system image
but n-different ethernet NICs we can put in our hardware)

cheers
	holger