Messages in this thread | | | Date | Sat, 20 Mar 2004 03:53:12 +0100 | From | Johannes Stezenbach <> | Subject | Re: [PATCH] barrier patch set |
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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?
I think the barrier code uses drive->id to determine if the write cache is enabled.
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