How to correctly load a driver without device tree?

How to correctly load a driver without device tree?

[kipade]

Now, most of kernel device are initialized by its driver according by
what described within device tree block. Here, the dtb was parsed
and used during kernel booting. If so, I want to load a device driver
after kernel booting using insmod, there would be no device tree
block present, so, the device would not be configured correctly.
so, how to make it usable?

Regards,
kipade.
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How to correctly load a driver without device tree?

[Greg KH]

On Wed, Jun 20, 2018 at 02:36:52PM +0800, kipade wrote:
> Now, most of kernel device are initialized by its driver according by
> what described within device tree block. Here, the dtb was parsed
> and used during kernel booting. If so, I want to load a device driver
> after kernel booting using insmod, there would be no device tree
> block present, so, the device would not be configured correctly.
> so, how to make it usable?

Why can you not build it into your kernel?

How to correctly load a driver without device tree?

[kipade]

That's a usb host driver. As I know, the whole usb subsystem
initialization would take up to 2 seconds while booting. In
another word, that will make the system booting time more
longer. So, I have to build all the usb driver as module and
insert them latter, when the system was usable.

On 2018?06?20? 16:01, Greg KH wrote:
> On Wed, Jun 20, 2018 at 02:36:52PM +0800, kipade wrote:
>> Now, most of kernel device are initialized by its driver according by
>> what described within device tree block. Here, the dtb was parsed
>> and used during kernel booting. If so, I want to load a device driver
>> after kernel booting using insmod, there would be no device tree
>> block present, so, the device would not be configured correctly.
>> so, how to make it usable?
> Why can you not build it into your kernel?
>
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

How to correctly load a driver without device tree?

[Gajjar Akash]

Hi there,

If you are using systemd, you can make your own Target like early.target
and load modules without udev.

But you need to load modules without device tree, I guess that's not
possible.

your system is booting without device tree?

Thanks,
Akash

On Wed, Jun 20, 2018, 14:03 kipade <kipade@163.com> wrote:

> That's a usb host driver. As I know, the whole usb subsystem
> initialization would take up to 2 seconds while booting. In
> another word, that will make the system booting time more
> longer. So, I have to build all the usb driver as module and
> insert them latter, when the system was usable.
>
> On 2018?06?20? 16:01, Greg KH wrote:
> > On Wed, Jun 20, 2018 at 02:36:52PM +0800, kipade wrote:
> >> Now, most of kernel device are initialized by its driver according by
> >> what described within device tree block. Here, the dtb was parsed
> >> and used during kernel booting. If so, I want to load a device driver
> >> after kernel booting using insmod, there would be no device tree
> >> block present, so, the device would not be configured correctly.
> >> so, how to make it usable?
> > Why can you not build it into your kernel?
> >
> >
> > _______________________________________________
> > Kernelnewbies mailing list
> > Kernelnewbies at kernelnewbies.org
> > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
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How to correctly load a driver without device tree?

[Greg KH]

On Wed, Jun 20, 2018 at 04:30:40PM +0800, kipade wrote:
> That's a usb host driver. As I know, the whole usb subsystem
> initialization would take up to 2 seconds while booting. In
> another word, that will make the system booting time more
> longer. So, I have to build all the usb driver as module and
> insert them latter, when the system was usable.

Then use async probing and/or deferred probing.  Or even better yet, fix
the driver to not wait 2 seconds when booting, that should not happen.

good luck!

greg k-h

How to correctly load a driver without device tree?

[kipade]

I don't use systemd on my arm linux board. I use init.
My system is booting with device tree. But, some node
were destroyed after booting completed. So, when
I use insmod loading the driver, it would match no
device.

On 2018?06?20? 16:58, Gajjar Akash wrote:
> Hi there,
>
> If you are using systemd, you can make your own Target like 
> early.target and load modules without udev.
>
> But you need to load modules without device tree, I guess that's not 
> possible.
>
> your system is booting without device tree?
>
> Thanks,
> Akash
>
> On Wed, Jun 20, 2018, 14:03 kipade <kipade@163.com 
> <mailto:kipade@163.com>> wrote:
>
>     That's a usb host driver. As I know, the whole usb subsystem
>     initialization would take up to 2 seconds while booting. In
>     another word, that will make the system booting time more
>     longer. So, I have to build all the usb driver as module and
>     insert them latter, when the system was usable.
>
>     On 2018?06?20? 16:01, Greg KH wrote:
>     > On Wed, Jun 20, 2018 at 02:36:52PM +0800, kipade wrote:
>     >> Now, most of kernel device are initialized by its driver
>     according by
>     >> what described within device tree block. Here, the dtb was parsed
>     >> and used during kernel booting. If so, I want to load a device
>     driver
>     >> after kernel booting using insmod, there would be no device tree
>     >> block present, so, the device would not be configured correctly.
>     >> so, how to make it usable?
>     > Why can you not build it into your kernel?
>     >
>     >
>     > _______________________________________________
>     > Kernelnewbies mailing list
>     > Kernelnewbies at kernelnewbies.org
>     <mailto:Kernelnewbies@kernelnewbies.org>
>     > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
>
>     _______________________________________________
>     Kernelnewbies mailing list
>     Kernelnewbies at kernelnewbies.org
>     <mailto:Kernelnewbies@kernelnewbies.org>
>     https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>

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How to correctly load a driver without device tree?

[kipade]

If so, I think that's the perfect resolution for that.
and, what should I do next for that way?

On 2018?06?20? 20:31, Greg KH wrote:
> On Wed, Jun 20, 2018 at 04:30:40PM +0800, kipade wrote:
>> That's a usb host driver. As I know, the whole usb subsystem
>> initialization would take up to 2 seconds while booting. In
>> another word, that will make the system booting time more
>> longer. So, I have to build all the usb driver as module and
>> insert them latter, when the system was usable.
> Then use async probing and/or deferred probing.  Or even better yet, fix
> the driver to not wait 2 seconds when booting, that should not happen.
>
> good luck!
>
> greg k-h