lkml.org 
[lkml]   [2004]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH] barrier patch set
    Date
    On Saturday 20 of March 2004 03:53, Johannes Stezenbach wrote:
    > Bartlomiej Zolnierkiewicz wrote:
    > > On Saturday 20 of March 2004 02:48, Johannes Stezenbach wrote:
    > > > hdparm -i and -I ultimately both interpret WIN_IDENTIFY result, and
    > > > both test bit 0x0020 of word 85. So it's unclear to me why they report
    > > > a different write cache setting. I added a hexdump to dump_identity()
    > > > in hdparm.c, and found that bit 0x0020 of word 85 is always set.
    > >
    > > or WIN_PIDENTIFY to be strict but
    > >
    > > -i returns _cached_ (read when the device was probed) identify data
    > > (uses HDIO_GET_IDENTIFY ioctl)
    > > -I reads _current_ data directly from the device
    > > (uses HDIO_DRIVE_CMD ioctl)
    >
    > Oh, right.
    >
    > But: HDIO_GET_IDENTITY returns drive->id, and surely drive->id
    > is used internally. So isn't it a bug that drive->id is not
    > updated when the write cache setting is changed?

    No, drive->id shouldn't be changed.

    > I think the barrier code uses drive->id to determine if the
    > write cache is enabled.

    The barrier code depends on drive->wcache.

    Regards,
    Bartlomiej

    -
    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: 2005-03-22 14:01    [W:0.029 / U:35.120 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site