lkml.org 
[lkml]   [2012]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH v3.4-rc3] MTD: NAND: ams-delta: Fix request_mem_region() failure
Date
On Fri, 4 May 2012 10:11:25 Tony Lindgren wrote:
> Hi,
>
> * Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> [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
the
> > OMAP1
> > > > MPU I/O device, but are used for controlling different sets of
I/O
> > 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
being
> > free
> > > > of bugs and doing their job correctly, not stepping on each
others'
> > > > 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
have a
> > > small separate omap-specific MPUIO subsystem which will be used by
> > > drivers to access MPUIO?
> > >
> > > Another question - should request_mem_region() be also removed
from
> > the
> > > omap-gpio driver then? I think it is more sensible to put a
comment
> > > there that it is sharing MPIO with other drivers, instead of
having
> > 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
Artem
> > suggested? If not, what do you think should be a correct way to fix
the
> > regression?
>
> Well how about adding some exported functions to
drivers/gpio/gpio_omap.c
> like omap_mpuio_latch?
>
> For the regression fix, if you guys want to do what Janusz is
suggesting,
> then assuming the patch description also contains some decent long
term
> plan to properly fix it:
>
> Acked-by: Tony Lindgren <tony@atomide.com>

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.

Regards,
Janusz


\
 
 \ /
  Last update: 2012-05-04 21:41    [W:0.154 / U:0.764 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site