Messages in this thread | | | From | Bartlomiej Zolnierkiewicz <> | Subject | Re: libata/PATA: GPCMD_SET_STREAMING via SG_IO does nothing | Date | Thu, 15 Nov 2007 21:55:30 +0100 |
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Hi,
On Wednesday 14 November 2007, Mark Lord wrote: > Sebastian Kemper wrote: > > Hi Mark! > > > > On Wed, Nov 14, 2007 at 11:41:37AM -0500, Mark Lord wrote: > >> Ahh.. got it. The host_status returned (not checked by that code) was 7, > >> which means "host error". > >> > >> In this case, that's because the cmd_len is (16), which is too large for > >> ATAPI. > >> It needs to be changed to (12) instead. > > > > I don't understand. You seem to use a cmd_len of 16 in hdparm yourself. > .. > > Really? Where? > > > > And why does it work with the "old" ATA driver and not with libata if > > 16 is too large for ATAPI in general? > .. > > Now that *is* the question. > And the answer appears to be that ide-cd.c ignores the passed-in cmd_len, > and replaces it with: > > cmd_len = COMMAND_SIZE(rq->cmd[0]); > > That's a SCSI macro to calculate the correct cmd_len based on the SCSI opcode, > which is very appropriate here. We should do that too (we don't) in libata. > > But not exactly as IDE does it -- that's actually a bug: the code needs to also > check that the new cmd_len is no larger than the original, or we'll get an Oops. > > I'll cook up a patch for that shortly and try it before posting it here.
Could you please also fix ide-cd while at it?
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