On Monday 28 February 2005 16:12, Tejun Heo wrote: > Bartlomiej Zolnierkiewicz wrote: > > On Sunday 27 February 2005 05:51, Tejun Heo wrote: > > > >> Hello, Bartlomiej, > >> > >>On Thu, Feb 24, 2005 at 03:45:39PM +0100, Bartlomiej Zolnierkiewicz wrote: > >> > >>>Original patch from Tejun Heo <[EMAIL PROTECTED]>, > >>>ported over recent IDE changes by me. > >>> > >>>* teach ide_tf_get_address() about CHS > >> > >> IMHO, as patch #4 moves LBA/CHS selection into taskfile, I think > >>using taskfile->device to determine whether LBA or CHS is used instead > >>of drive->select makes more sense. > >> > >> > >>>* use ide_tf_get_address() and remove ide_get_error_location() > >> > >> IIRC, error responses for WIN_FLUSH_CACHE is in CHS if the LBA bit in > >>the device register is zero; likewise, in LBA if the LBA bit is one. > >>I don't know if drives can change the LBA bit when posting error > >>result. The original code reads back the device register on error to > >>determine whether to interpret the error response in CHS or LBA. > >>(ATA/ATAPI-6 isn't clear on this issue. Is ATA/ATAPI-7 updated?) > > > > > > The thing is that LBA bit is marked as "na" for FLUSH CACHE > > in all ATA/ATAPI drafts that I've seen. > > > > Yeah, and nothing is mentioned about the LBA bit in the normal output > description even though the lcyl, hcyl.. registers are described to be > in either form of CHS or LBA. Strange... > > > > >> This change combined with patch #2/#5 can make error address > >>calculation wrong on LBA28 drives. I think setting the LBA bit in the > >>device register according to the drive's addressing mode in > >>ide_task_init_flush() and use taskfile->device in ide_tf_get_address() > >>should fix the problem. > > > > > > I will change the code to set LBA bit, it shouldn't hurt. :-) > > IMHO, there can be cases where just setting the LBA bit isn't enough. > Theoretically, drives can report CHS and clear the LBA bit in the > device register even when the LBA bit was set when the command was > issued. Maybe the intention of the original code was to handle > something like this?
/me suspects that disks that support LBA always report LBA and disks that use only CHS always report CHS but this is pure speculation - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
