[lkml]   [2001]   [Apr]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: ServerWorks LE and MTRR wrote:
    > On Sun, 29 Apr 2001, Steffen Persvold wrote:
    > > I've learned it the hard way, I have two types : Compaq DL360 (rev 5) and a
    > > Tyan S2510 (rev 6). On the compaq machine I constantly get data corruption on
    > > the last double word (4 bytes) in a 64 byte PCI burst when I use write
    > > combining on the CPU. On the Tyan however the transfer is always ok.
    > >
    > Are you sure that is not due to board design differences?

    No I can't be 100% certain that the layout of the board isn't the reason since
    I haven't asked ServerWorks about this and it doesn't say anything in their
    docs (yes my company has the NDA, so I shouldn't get to much in detail here),
    but if this was the case it would be totally wrong to disable write combining
    on any LE chipset.

    The test case that I have been using to trigger this is sort of special because
    we are using SCI shared memory adapters to write (with PIO) into remote nodes
    memory, and the bandwidth tends to get quite high (approx 170 MByte/sec on LE
    with write combining). I've been able to run this case on 5 different
    motherboards using the LE and HE-SL ServerWorks chipsets, but only two of them
    are LE (the DL360 and the S2510). Everything works fine with write-combining on
    every motherboard except the DL360 (which has rev 5).

    One basic test case that I haven't tried, could be to enable write-combining on
    your PCI graphics adapter memory and see if the X display gets screwed up.

    I will try to get some information from ServerWorks about this problem, but I'm
    not sure if ServerWorks would be happy if I told you the answer (because of the

    Steffen Persvold Systems Engineer
    Email : Scali AS (
    Norway : Tel : (+47) 2262 8950 Olaf Helsets vei 6
    Fax : (+47) 2262 8951 N-0621 Oslo, Norway

    USA : Tel : (+1) 713 706 0544 10500 Richmond Avenue, Suite 190
    Houston, Texas 77042, USA
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 12:52    [W:0.023 / U:1.440 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site