lkml.org 
[lkml]   [2007]   [Nov]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRE: [PATCH 1/2] msi: set 'En' bit of MSI Mapping Capability on HT platform
    Date
    From

    > Isn't there a way we can make this work for any upstream HT
    > bridge, rather than only for specific NVIDIA chipsets?


    The lines Peer indicates below will work for any vendor's bridge device
    that implements an HT MSI mapping and is an upstream bridge of the
    endpoint requesting MSI.

    On some NVIDIA chipsets, the host bridge that implements HT MSI mapping
    is not hierarchically upstream from the MSI endpoint; it may be a peer
    on the same bus as the endpoint or the PCIe root complex that's above
    the endpoint. The NVIDIA-specific code in the patch is to detect those
    specific chipsets where this can occur. We have tested the patch with
    both internal and PCI Express MSI endpoints on each of these NVIDIA
    chipsets.

    It may be that other vendors have Hypertransport chipsets with similar
    requirements for HT MSI mapping, but we don't have that information or
    the ability to test code on those vendors' chipsets.

    Regards,

    Andy
    --
    Andy Currid, NVIDIA Corporation
    acurrid@nvidia.com 408 566 6743


    -----Original Message-----
    From: Peer Chen
    Sent: Sunday, November 25, 2007 20:02
    To: Robert Hancock; peerchen
    Cc: linux-kernel; akpm; Andy Currid
    Subject: RE: [PATCH 1/2] msi: set 'En' bit of MSI Mapping Capability on
    HT platform

    I think the following lines are suitable for other bridges besides
    nvidia's, :) :
    ===================
    + if (pci_enable_msi_ht_cap(dev) != 0) {
    + return 0;
    + } else {
    + /* Get upstream bridge device handle */
    +
    + bridge_dev = dev->bus->self;
    + while(bridge_dev != 0) {
    + if (pci_enable_msi_ht_cap(bridge_dev) !=
    0) {
    + return 0;
    + } else
    + bridge_dev =
    bridge_dev->bus->self;
    + }
    +
    + return 1;
    + }


    BRs
    Peer Chen

    -----Original Message-----
    From: Robert Hancock [mailto:hancockr@shaw.ca]
    Sent: Monday, November 26, 2007 2:34 AM
    To: peerchen
    Cc: linux-kernel; akpm; Peer Chen; Andy Currid
    Subject: Re: [PATCH 1/2] msi: set 'En' bit of MSI Mapping Capability on
    HT platform

    peerchen wrote:
    > According to the HyperTransport spec, 'En' indicate if the MSI Mapping
    is active. So it should be set when enable the MSI.
    >
    > The patch base on kernel 2.6.24-rc3
    >
    > Signed-off-by: Andy Currid <acurrid@nvidia.com>
    > Signed-off-by: Peer Chen <pchen@nvidia.com>

    Isn't there a way we can make this work for any upstream HT bridge,
    rather than only for specific NVIDIA chipsets?

    --
    Robert Hancock Saskatoon, SK, Canada
    To email, remove "nospam" from hancockr@nospamshaw.ca Home Page:
    http://www.roberthancock.com/

    -----------------------------------------------------------------------------------
    This email message is for the sole use of the intended recipient(s) and may contain
    confidential information. Any unauthorized review, use, disclosure or distribution
    is prohibited. If you are not the intended recipient, please contact the sender by
    reply email and destroy all copies of the original message.
    -----------------------------------------------------------------------------------
    -
    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: 2007-11-26 06:21    [W:0.030 / U:29.452 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site