* To built-in Driver, When the corresponding node under /dev created?
@ 2012-03-27 6:39 Li Haifeng
2012-03-27 20:53 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Li Haifeng @ 2012-03-27 6:39 UTC (permalink / raw)
To: linux-fsdevel; +Cc: linux-kernel
As you know, the node under /dev are managed by udevd daemon.
But to the built-in driver module, when the module is probed in kernel
space, udevd daemon doesn't running. So, to ttyS node, when the
built-in driver module was probed, when was the /dev/ttyS created?
Thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: To built-in Driver, When the corresponding node under /dev created?
2012-03-27 6:39 To built-in Driver, When the corresponding node under /dev created? Li Haifeng
@ 2012-03-27 20:53 ` Greg KH
2012-03-28 0:44 ` Li Haifeng
0 siblings, 1 reply; 3+ messages in thread
From: Greg KH @ 2012-03-27 20:53 UTC (permalink / raw)
To: Li Haifeng; +Cc: linux-fsdevel, linux-kernel
On Tue, Mar 27, 2012 at 02:39:37PM +0800, Li Haifeng wrote:
> As you know, the node under /dev are managed by udevd daemon.
Not always, usually the node is created by devtmpfs on most modern
distros.
> But to the built-in driver module, when the module is probed in kernel
> space, udevd daemon doesn't running. So, to ttyS node, when the
> built-in driver module was probed, when was the /dev/ttyS created?
devtmpfs does it.
Also, look at your distro startup code, it sets things up properly when
userspace starts up and has udev go through things and set up the nodes
then.
good luck,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: To built-in Driver, When the corresponding node under /dev created?
2012-03-27 20:53 ` Greg KH
@ 2012-03-28 0:44 ` Li Haifeng
0 siblings, 0 replies; 3+ messages in thread
From: Li Haifeng @ 2012-03-28 0:44 UTC (permalink / raw)
To: Greg KH; +Cc: linux-fsdevel, linux-kernel
Thanks.
I also found it @ http://lwn.net/Articles/330985/
On Wed, Mar 28, 2012 at 4:53 AM, Greg KH <gregkh@linuxfoundation.org> wrote:
> On Tue, Mar 27, 2012 at 02:39:37PM +0800, Li Haifeng wrote:
>> As you know, the node under /dev are managed by udevd daemon.
>
> Not always, usually the node is created by devtmpfs on most modern
> distros.
>
>> But to the built-in driver module, when the module is probed in kernel
>> space, udevd daemon doesn't running. So, to ttyS node, when the
>> built-in driver module was probed, when was the /dev/ttyS created?
>
> devtmpfs does it.
>
> Also, look at your distro startup code, it sets things up properly when
> userspace starts up and has udev go through things and set up the nodes
> then.
>
> good luck,
>
> greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-03-27 6:39 To built-in Driver, When the corresponding node under /dev created? Li Haifeng
2012-03-27 20:53 ` Greg KH
2012-03-28 0:44 ` Li Haifeng
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