Re: [PATCH 20/51] Input: atmel_mxt_ts - Set default irqflags when there is no pdata

[Yufeng Shen <miletus@chromium.org>]

On Mon, May 26, 2014 at 1:23 AM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
>
> On Fri, May 23, 2014 at 12:37:46PM -0400, Yufeng Shen wrote:
> > On Thu, May 22, 2014 at 10:29 AM, Nick Dyer <nick.dyer@itdev.co.uk> wrote:
> > >
> > > Dmitry Torokhov wrote:
> > > > On Thu, Jul 18, 2013 at 07:17:44PM +0200, rydberg@euromail.se wrote:
> > > >>> From: Yufeng Shen <miletus@chromium.org>
> > > >>> This is the preparation for supporting the code path when there is
> > > >>> platform data provided and still boot the device into a sane state
> > > >>> with backup NVRAM config.
> > > >>>
> > > >>> Make the irqflags default to be IRQF_TRIGGER_FALLING if no platform data is
> > > >>> provided.
> > > >
> > > > I think if there is no platform data we should use 0 as IRQ falgs and
> > > > assume that IRQ line is properly configured by the board code or via
> > > > device tree.
> > >
> > > Beson/Yufeng - do you still have a requirement to probe without platform
> > > data or device tree? I'm just merging in some changes to add device tree
> > > support, and it would simplify things a bit if I can drop this patch.
> >
> >
> > It has been working for quite a while for boards/devices that don't
> > provide platform
> > data. If we drop the default IRQ flags, sure we can add code for each
> > board to configure
> > the IRQ separately, but that's just adding extra work. Is there strong
> > reason why we
> > should not do the default setting in the driver if it is not already
> > configured in platform
> > data ?
>
>
> I am not saying that board code needs to add platform data. I am saying
> that the board code needs to set up interrupt properly (via
> irq_set_irq_type() or similar) and then the driver can use 0 as irqflags
> argument in request_irq() in absence of DT/platform data.
>
> Thanks.
>

So my argument is mainly based on that the existing code is working (boards
that do not have platform data are relying on the driver to set the
default irq),
and change the default value would need extra work to setup the irq, say as you
suggested through irq_set_irq_type(). I am no expert in irq so it could be true
that your suggested way is indeed better. I am in favor of keeping
this patch is only
because it requires no extra change for existing code that are using it.



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> Dmitry
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