lkml.org 
[lkml]   [2015]   [May]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Why isn't IRQ shared for i2c-ocore
On Fri, 08 May 2015, Geert Uytterhoeven wrote:

> On Thu, May 7, 2015 at 9:01 AM, Lee Jones <lee.jones@linaro.org> wrote:
> >> I have a follow up question regarding interrupt. I see many I2C bus drivers
> >> request interrupt with flag = 0. Why not using IRQF_SHARED?
> >
> > Probably because that particular IRQ is only used by the I2C
> > Controller. I'm not exactly sure that you're getting at? Why do you
> > think it should be shared? You should only flag it as shared if it
> > is.
>
> However, that's something the driver can't know.
> Sharing interrupts is an integration property. The same IP core may share its
> interrupt on one SoC, and not on another.

I guess that would depend on the IP. If this is part of an MFD, you'd
know if you only hand a single interrupt line coming into the chip or
not. If the IP can be moved around (copy & pasted) into different
chips, then yes, that might change.

How does one share an interrupt with other drivers if all them don't
know the IRQ is shared thought?

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog


\
 
 \ /
  Last update: 2015-05-08 09:21    [W:0.071 / U:51.932 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site