Re: [Patch v4 01/12] microblaze: irqchip: Move intc driver to irqchip

From: Jason Cooper
Date: Fri Sep 02 2016 - 09:28:29 EST


Hi Michal, Zubair,

On Fri, Sep 02, 2016 at 12:27:54PM +0200, Michal Simek wrote:
> On 2.9.2016 12:06, Zubair Lutfullah Kakakhel wrote:
> > On 09/02/2016 07:25 AM, Michal Simek wrote:
...
> >> Also there is another copy of this driver in the tree which was using
> >> old ppc405 and ppc440 xilinx platforms.
> >>
> >> arch/powerpc/include/asm/xilinx_intc.h
> >> arch/powerpc/sysdev/xilinx_intc.c
> >>
> >> These should be also removed by moving this driver to generic folder.
> >
> > I didn't know about that drivers existence.
> >
> > This patch series already touches microblaze, mips and irqchip.
> > Both microblaze and mips platforms using this driver are little-endian.
>
> MB is big ending too and as you see there is big endian support in the
> driver already.
>
> >
> > Adding a big-endian powerpc driver + platform to the mix is going to
> > complicate the series further and make it super hard to synchronize
> > various subsystems, test stuff, and then move the drivers without
> > breakage.

The whole point of Linus' push to move drivers out of arch/ is to
reduce code duplication and create more robust drivers.

> > I'd highly recommend letting this move happen. And then the powerpc
> > driver can transition over time to this driver.

I've seen this argument before, and despite everyone's best intentions,
it never happens. :(

We have linux-next, 0-day and other resources to test these sorts of
changes and catch errors before they hit mainline.

Let's take our time and do it right.

thx,

Jason.