Re: [PATCH v2 06/18] m68k: Replace setup_irq() by request_irq()

From: Finn Thain <fthain@telegraphics.com.au>
To: afzal mohammed <afzal.mohd.ma@gmail.com>
Cc: linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org,
	Greg Ungerer <gerg@linux-m68k.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Geert Uytterhoeven <geert@linux-m68k.org>
Subject: Re: [PATCH v2 06/18] m68k: Replace setup_irq() by request_irq()
Date: Mon, 2 Mar 2020 17:26:17 +1100 (AEDT)	[thread overview]
Message-ID: <alpine.LNX.2.22.394.2003021717150.8@nippy.intranet> (raw)
In-Reply-To: <20200301061327.GA5229@afzalpc>

On Sun, 1 Mar 2020, afzal mohammed wrote:

> Hi,
> 
> On Sun, Mar 01, 2020 at 02:26:33PM +1100, Finn Thain wrote:
> 
> > BTW, how do you distinguish between "new code" and "legacy code"?
> 
> setup_irq() was used in olden days, nowadays request_irq(). Though there 
> are exceptions of trying to use setup_irq() even recently, but there has 
> been pushback when people notice it like Thomas had done [1], and i saw 
> recently one in mips smp support series & suggested not to use it (that 
> code iiuc they had it out of upstream for a long time).
> 
> So existence of setup_irq() in general i have considered to be legacy 
> code.
> 

I see. You're defining "legacy code" in this case to mean code that uses a 
deprecated API, that needs to be modernized.

> > And why would you choose to do that when you are writing a tree-wide 
> > semantic patch?
> 
> The way i came up with this series is that while trying to understand 
> irq internals, came across [1], so then decided to do cleanup and i 
> thought scripting it would make it easy & also had been wanting to get 
> familiar w/ cocci, so decided to try it, but also realized that i cannot 
> fully automate it (Julia said my patch is okay, so i felt cocci cannot 
> fully automate w/o investing considerable effort in cocci), so even w/ 
> this v2, there are lot of manual changes, though cocci made it easier.
> 
> > I took Geert's comments to be architecture agnostic but perhaps I 
> > misunderstood.
> 
> And Thomas suggested to make improvements over script generated o/p [2] 
> and only consider scripting as an initial first step. So the way i am 
> making changes now is to take suggestions from Thomas to be applied 
> treewide, at the same time also take care of suggestions from 
> arch/subsytem maintainer/mailing list in the relevant patches, since 
> arch maintainers are the ones owning it.
> 

Thanks for the detailed explanation.

I had assumed that your intention was to find a consensus so that the 
whole tree could be consistently and automatically improved. My mistake.

> Sometimes had a feeling as though the changes in this series is akin to 
> cutting the foot to fit the shoe ;), but still went ahead as it was 
> legacy code, easier & less error prone. But now based on the overall 
> feedback, to proceed, i had to change.
> 

Not based on feedback from me I hope -- I have no veto in this case, as 
you can see from MAINTAINERS.

> Regards
> afzal
> 
> [1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanos
> [2] https://lore.kernel.org/lkml/87sgiwma3x.fsf@nanos.tec.linutronix.de/
> 