lkml.org 
[lkml]   [1998]   [Dec]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectSecond Thought (Re: Re[2]: Small error?? in IDE dma processing?)

    First lets run some system crashes...........(which I did)....even worse!!

    Then look at the ATA/ATAPI-4 spec T13-1153D Revision 17 30-Oct-97 page 234,
    again. The flow charts on DMA procedure to my reading again (not late at
    night in a dimly lit room at 1am).
    Both branches of the test 0IEN=0 :

    At test DEVICE: nIEN=0 ?

    No -> Host : Read of Status register is recommended.
    NOTE : Status register is read to clear pending interrupt.
    END

    Yes -> Device : Assert INTRQ
    Host : Read Status register
    Device : Negate INTRQ
    END


    wait for device to issue interrupt request
    then first read the status ***
    then clear the interrupt

    ***
    It is not all clear if this is refering to DMA or Drive Status; however,
    it is reasonable to assume that it is DMA first.

    Like the original code.

    A closer look at 29055002.pdf (intel), 29765804.pdf (intel),
    d1153r17.pdf, and some source code on loan from HighPoint Tech.
    (a public branch of Triton).

    I now think the original code is correct.
    Note that I will test this question more objectively on a drive that
    doesn't have some non-correctable error accounting.
    (forgot to bad block check and mark the drive first, duh....)

    Have you switched the code and tested it youself yet?

    On Wed, 16 Dec 1998 jason.harp@mail.ray.ca wrote:

    >
    > Will you make the appropriate changes to 2.0 and 2.1 IDE code?
    >

    If this is the correct solution, yes. I am now not convinced that it is
    the correct answer. The follow up docs on the PIIX/PIIX3 have a DMA
    BusMaster bit order corrections, also.

    Cheers,
    Andre Hedrick
    The IDE-FNG for Linux
    The APC UPS Specialist for Linux

    http://www.dyer.vanderbilt.edu/server/udma/
    http://www.dyer.vanderbilt.edu/server/apcupsd/apcupsd-3.5.2.bin.tar.gz










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

    \
     
     \ /
      Last update: 2005-03-22 13:46    [W:0.022 / U:2.100 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site