Re: [V2] mtd: devices: docg3:- Handle return value of devm_ioremap.

[arvind Yadav]

Hi Boris,

Yes, It's possible that two driver can use same iomem region.
For example you can check
commit id - : 33cf75656923ff11d67a937a4f8e9344f58cea77

Here, It's not required.

Thanks
-Arvind

On Monday 12 December 2016 10:34 PM, Boris Brezillon wrote:
> Hi Arvind,
>
> On Mon, 12 Dec 2016 21:33:05 +0530
> arvind Yadav <arvind.yadav.cs@xxxxxxxxx> wrote:
>
> > There is problem, if you will use devm_ioremap_resource instead of
> > devm_ioremap,
> > than devm_ioremap_resource will call request_mem_region().
> > request_mem_region() allows to tell the kernel that this driver is going
> > to use
> > this range of I/O addresses, which will prevent other drivers to make an
> > overlapping call to request_mem_region If other driver want to use same
> > address
> > space to access then it will not allow. Means we can not share same
> > address space
> > between two driver.
> The question is, is it required here? In general, allowing 2 different
> drivers from touching the same iomem region is a bad idea, so, if
> there's a reason to allow that here, I'd like to know more about it.
>
> Thanks,
>
> Boris