Re: Device probe issue with an em(4) compatible device

From: M. Warner Losh (imp_at_bsdimp.com)
Date: 09/30/04

  • Next message: M. Warner Losh: "Re: Device probe issue with an em(4) compatible device" 
    Date: Wed, 29 Sep 2004 18:02:27 -0600 (MDT)
To: bcg@intelli7.com

    In message: <1096485467.2670.1127.camel@localhost.localdomain>
                Brenden Grace <bcg@intelli7.com> writes:
    : On Wed, 2004-09-29 at 13:37, Peter Buckingham wrote:
    : > why compile the em driver in at all? it won't probe the device if it
    : > doesn't exist ;-)
    :
    : because I need it ...

    As opposed to just hacking the em driver?

    : > otherwise, just add some code to the em's probe routine to check for
    : > your subvendor, subdevice pair and exit without attaching.
    :
    : Well sure (though ugly), but I think having it just return a negative
    : number would be a better fix than that. I was more interested in why the
    : em driver (and others) returns 0 and ends the probing of a device that
    : it could possibly only partially support (based on its matching of
    : PCI_ANY_ID). If I understand DEVICE_PROBE(9) correctly it seems that the
    : whole reason for the negative return scale is to avoid this very issue.

    That's correct. PCI_ANY_ID has nothing to do with it. If em_probe
    returns 0, it trumps all other drivers for that device that haven't
    had a chance to bid (as well as the potential drivers that bid a
    negative number).

    Warner
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