[PATCH v7 1/3] MTD : add the common code for GPMI-NFC controller driver

[w.sang@pengutronix.de (Wolfram Sang)]

Hi Shawn,

> > > I would suggest leave this gpmi specific quirk to gpmi driver to sort
> > > out.  With the following mxs-dma change, it should work if gpmi driver
> > > can pass the valid gpmi irq number for only one gpmi channel, and -1
> > > for all others.
> > 
> > ...which brings us right into the 'NO_IRQ is 0' discussion :)
> > 
> Though I do not know what it means exactly, number 0 is an valid IRQ
> on both mx23 and mx28 (see mx23.h and mx28.h).

It could be remapped. It is a looong story. Start here if you are interested:

http://lkml.org/lkml/2005/11/21/221
http://yarchive.net/comp/linux/no_irq.html

Currently, it's a can of worms. Hopefully, irq_desc might help somewhen.

> > Other than that, [thinking loud] this will help if all irq-sharing
> > channels are handled by the same driver. If not, we would just add
> > IRQF_SHARED (hopefully this will never be needed). Yup, sounds
> > reasonable to me. Will give it a second thought later, though.
> > 
> GPMI is the only mxs-dma user that gets irq-sharing.  So yes, all
> irq-sharing channels are handled by the same driver, gpmi-nfc :)

Currently, yes. But we have to make it future-proof.

Regards,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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