[PATCH v3.4-rc3] MTD: NAND: ams-delta: Fix request_mem_region() failure

Janusz Krzysztofik jkrzyszt at tis.icnet.pl
Mon Apr 30 14:09:54 EDT 2012


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?

Thanks,
Janusz



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