jkrzyszt at tis
May 4, 2012, 12:23 PM
Post #7 of 7
On Fri, 4 May 2012 10:11:25 Tony Lindgren wrote:
Re: [PATCH v3.4-rc3] MTD: NAND: ams-delta: Fix request_mem_region() failure
[In reply to]
> * Janusz Krzysztofik <jkrzyszt [at] tis> [120430 11:15]:
> > Dnia czwartek, 26 kwietnia 2012 08:20:59 Artem Bityutskiy pisze:
> > > On Wed, 2012-04-25 at 19:01 +0200, Janusz Krzysztofik wrote:
> > > > Both drivers use separate subsets of registers that belong to
> > OMAP1
> > > > MPU I/O device, but are used for controlling different sets of
> > pins.
> > > > The NAND driver reads/writes the folowing registers:
> > > > - OMAP_MPUIO_INPUT_LATCH,
> > > > - OMAP_MPUIO_OUTPUT,
> > > > - OMAP_MPUIO_IO_CNTL,
> > > > while the keypad driver - the following:
> > > > - OMAP_MPUIO_KBR_LATCH,
> > > > - OMAP_MPUIO_KBC,
> > > > - OMAP_MPUIO_KBD_MASKIT
> > > > - OMAP_MPUIO_GPIO_DEBOUNCING.
> > > > Both subsets are non-overlapping, and we rely on the drivers
> > free
> > > > of bugs and doing their job correctly, not stepping on each
> > > > feet, I guess.
> > >
> > > First of all, I think this information should be in the commit
> > message.
> > > Also, some sort of comment in the driver code would be nice.
> > >
> > > If locking the memory region is too coarse approach, the should
> > > small separate omap-specific MPUIO subsystem which will be used by
> > > drivers to access MPUIO?
> > >
> > > Another question - should request_mem_region() be also removed
> > the
> > > omap-gpio driver then? I think it is more sensible to put a
> > > there that it is sharing MPIO with other drivers, instead of
> > an
> > > illusion of exclusive memory region ownership.
> > >
> > > But this is up to the OMAP community - I can take this patch to my
> > > l2-mtd tree if you get an ack from Tony or other OMAP guys.
> > Tony,
> > Would I get your Ack for this fix if I extend the commit message as
> > suggested? If not, what do you think should be a correct way to fix
> > regression?
> Well how about adding some exported functions to
> like omap_mpuio_latch?
> For the regression fix, if you guys want to do what Janusz is
> then assuming the patch description also contains some decent long
> plan to properly fix it:
> Acked-by: Tony Lindgren <tony [at] atomide>
Thanks. Now that we know you prefer to keep the memory requested from
inside the gpio-omap, which I was about to suggest to drop back as an
alternative fix, I'll try to cook a new description for my patch, and
perhaps add a comment replacing the request_mem_region function removed
from the ams-delta NAND driver, in order to satisfy both yours and
Artem's comments in a few days.
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