lkml.org 
[lkml]   [2012]   [Jul]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH V3 5/6] Avoid duplicate probe for of platform devices
    On Mon, Jul 09, 2012 at 03:46:59AM +0000, Li Yang-R58472 wrote:
    > > > I don't understand, why is this just showing up now? What changed to
    > > > cause this? Couldn't that be the real problem here?
    > > >
    > >
    > > The issue is showing up because we now probe devices twice.
    > > Previously, we just probe devices once. But now we changed the way of pci
    > > init which makes pci controllers should be probed earlier than other
    > > devices.
    > > So we have to probe pci nodes separately. Probe more than once is the
    > > root
    > > cause of this issue.
    > >
    > > The pci patchset I mentioned please refer to:
    > > http://patchwork.ozlabs.org/patch/163742/
    >
    > Let me try to clarify a little bit. The of platform bus normally
    > traverse the device tree to add all the devices. The change which
    > caused problem is that we need to probe PCIe RC devices at a earlier
    > stage of initialization.

    That sounds, wrong.

    > So we added these PCIe RC devices earlier than the normal device tree
    > traversal process. These PCIe RC devices will be scanned again during
    > the normal traversal and cause duplicated devices being added. Our
    > proposal is to deal with duplicated devices automatically and make it
    > possible to scan the device tree multiple times for devices to be
    > added.

    Then you need to put something in your own tree scanning logic to not
    try to register devices multiple times. How about a simple flag in your
    device structure instead of having to muck around in the driver core
    internals?

    Although one should seriously question the need to want to recan the bus
    and register devices at different times of the boot process...

    thanks,

    greg k-h


    \
     
     \ /
      Last update: 2012-07-09 22:02    [W:4.688 / U:0.212 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site