[linux-dvb] [RFC PATCH] Choose dvb adapter number with a driver specific module option

Janne Grunau janne-dvb at grunau.be
Thu Aug 2 17:03:00 CEST 2007

On Thursday 02 August 2007 05:25:12 Nick Andrew wrote:
> On Thu, Aug 02, 2007 at 03:15:04AM +0200, Janne Grunau wrote:
> > Dynamic loading of modules by udev on startup (aka coldplugging)
> > doesn't result in deterministic dvb adapter numbers.
> Isn't the usual response to write some udev rules to set the name
> based on device characteristics?  Thus taking the naming policy
> out of the module and into userspace.

It's another possibility.

> Since you're defining a numbering order when you load the module, if
> you have 2 or more devices which use the module then your solution
> doesn't solve the problem of controlling the numbers because it
> depends which device the kernel finds first.

This is currently not a problem, devices using the same driver are 
detected in a stable order.

> With udev, if there's 
> some way to distinguish between two of the same device, then rules
> can be written to set the name of each.

One of the problems with persistent names for dvb devices is the wide 
variaty of different devices which makes it hard to find attributes for 
an automatic persistent udev device naming.
I find adding module options simpler than adding udev rules. Also this 
solution is useable in embeddded devices which may come without udev.


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