Messages in this thread | | | Date | Thu, 10 Feb 2005 13:08:18 -0500 | From | Dmitry Torokhov <> | Subject | Re: [RFC][PATCH] add driver matching priorities |
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On Thu, 10 Feb 2005 12:18:37 -0500, Adam Belay <abelay@novell.com> wrote: > On Thu, 2005-02-10 at 00:41 -0800, Greg KH wrote: > > On Fri, Jan 28, 2005 at 05:30:04PM -0500, Adam Belay wrote: > > > Hi, > > > > > > This patch adds initial support for driver matching priorities to the > > > driver model. It is needed for my work on converting the pci bridge > > > driver to use "struct device_driver". It may also be helpful for driver > > > with more complex (or long id lists as I've seen in many cases) matching > > > criteria. > > > > > > "match" has been added to "struct device_driver". There are now two > > > steps in the matching process. The first step is a bus specific filter > > > that determines possible driver candidates. The second step is a driver > > > specific match function that verifies if the driver will work with the > > > hardware, and returns a priority code (how well it is able to handle the > > > device). The bus layer could override the driver's match function if > > > necessary (similar to how it passes *probe through it's layer and then > > > on to the actual driver). > > > > > > The current priorities are as follows: > > > > > > enum { > > > MATCH_PRIORITY_FAILURE = 0, > > > MATCH_PRIORITY_GENERIC, > > > MATCH_PRIORITY_NORMAL, > > > MATCH_PRIORITY_VENDOR, > > > }; > > > > > > let me know if any of this would need to be changed. For example, the > > > "struct bus_type" match function could return a priority code. > > > > > > Of course this patch is not going to be effective alone. We also need > > > to change the init order. If a driver is registered early but isn't the > > > best available, it will be bound to the device prematurely. This would > > > be a problem for carbus (yenta) bridges. > > > > > > I think we may have to load all in kernel drivers first, and then begin > > > matching them to hardware. Do you agree? If so, I'd be happy to make a > > > patch for that too. > > > > I think the issue that Al raises about drivers grabbing devices, and > > then trying to unbind them might be a real problem. > > I agree. Do you think registering every in-kernel driver before probing > hardware would solve this problem?
And what do you do with drivers that are built as modules?
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