Re: [RFC][PATCH] add driver matching priorities

From: Adam Belay (abelay_at_novell.com)
Date: 03/01/05

  • Next message: Adam Belay: "Re: [RFC] PCI bridge driver rewrite" 
    To: Greg KH <greg@kroah.com>
Date:	Mon, 28 Feb 2005 19:05:54 -0500

    On Fri, 2005-02-25 at 15:41 -0800, Greg KH wrote:
    > On Thu, Feb 10, 2005 at 04:37:03PM -0500, Adam Belay wrote:
    > > On Thu, 2005-02-10 at 18:45 +0000, Russell King wrote:
    > > > On Thu, Feb 10, 2005 at 12:18:37PM -0500, Adam Belay wrote:
    > > > > > 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?
    > > >
    > > > In which case, consider whether we should be tainting the kernel if
    > > > someone loads a device driver, it binds to a device, and then they
    > > > unload that driver.
    > > >
    > > > It's precisely the same situation, and precisely the same mechanics
    > > > as what I've suggested should be going on here. If one scenario is
    > > > inherently buggy, so is the other.
    > > >
    > >
    > > I think it would depend on whether the user makes the device busy before
    > > the driver is unloaded. Different device classes may have different
    > > requirements for when and how a device can be removed. Are there other
    > > issues as well? Maybe there are ways to improve driver start and stop
    > > mechanics.
    >
    > We never fail a device unbind from a driver, so this isn't as big a deal
    > as I originally thought. Yes, userspace can get messy, but as userspace
    > was the one that loaded the new driver to bind, it's acceptable.
    >
    > So, care to resubmit your patch?
    >

    Would you like me to include the portion that adds "*match" to "struct
    device_driver"? After some more thought, I began considering having
    driver priority be a static quality of a device driver. The question is
    whether we want a device driver to be able to return a variable priority
    based on bind device. Also, "*match" could be used to split some
    detection and validation out of "*probe". What are your reactions to
    this?

    Finally, should every in-kernel driver be registered before devices are
    detected?

    Thanks,
    Adam

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  • Next message: Adam Belay: "Re: [RFC] PCI bridge driver rewrite"

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