Re: [PATCH] Fix interface autodetection in legacy IDE driver (trial #2)

[Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>]

Hi,

On Tuesday, December 27, 2016 07:38:18 PM David Miller wrote:
> From: Luiz Carlos Ramos <lramos.prof@yahoo.com.br>
> Date: Tue, 27 Dec 2016 22:33:35 -0200
> 
> > So, ide_generic_init() should test *primary for 1 in the case of an
> > existing IDE primary resource, and *secondary for 1 in the case of a
> > secondary IDE resource.
> > 
> > Unpatched code checks both for zero in order to set the proper bits in
> > probe_mask, and IMHO this is reversed logic.
> 
> Right, and I can't see how this is intentional at all.

If PCI IDE resource is found we shouldn't do the probe automatically
as ide-generic is not the proper driver to run the hardware.  IOW we
only want to do automatic probe if no PCI IDE resources are found (if
primary/secondary == 0).  In such case we are most likely running on
pre-PCI system and should be probing for legacy ISA IDE ports. Please
note they are using the same I/O resources as PCI IDE ones (!).

[ Please see the reply to Luiz for the full explanation. ]

I know that you're busy and don't have time for in-depth analysis
of non-obvious IDE patches.  I would like to help and (co-)maintain 
the IDE subsystem (deep maintenance mode policy would of course be
preserved).

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics