lkml.org 
[lkml]   [2012]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: One problem in reassign pci bus number?
    From
    On Sun, Apr 22, 2012 at 8:52 AM, Richard Yang
    <weiyang@linux.vnet.ibm.com> wrote:
    > All,
    >
    > I am reading the pci_scan_bridge() and not sure what will happen in
    > following situation.
    >
    > Suppose the kernel is not passed the pci=assign-busses.
    >
    > Below is a picture about the pci system.
    >
    >                   +-------+
    >                   |       | root bridge(0,255)
    >                   +---+---+
    >                       |          Bus 0
    >      -----+-----------+------------------------------+--
    >           |                                          |
    >           |                                          |
    >           |                                          |
    >      +----+----+                               +-----+-----+
    >      |         |  B1(1,15)                     |           |B2(16,28)
    >      +----+----+                               +-----+-----+
    >           |  Bus 1                                   |    Bus 16
    >      -----+-----------------------         ----------+----------------
    >                            |
    >                       +----+----+
    >                       |         | B3
    >                       +---------+
    >
    > Suppose B1 and B2 works fine with the BIOS, which get the right bus
    > number and range.
    >
    > B3 does not works fine with the BIOS, which doesn't get the bus number.
    >
    > So in pci_scan_bridge(), B3 will be met in the second pass and get bus
    > number 16?
    > Would this be a conflict?

    busn_alloc patchset should address your concern.

    git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git
    for-pci-busn-alloc

    Yinghai
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2012-04-23 22:15    [from the cache]
    ©2003-2014 Jasper Spaans. Advertise on this site