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From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Vladimir Oltean <olteanv@gmail.com>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	"arnd@arndb.de" <arnd@arndb.de>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"sergei.shtylyov@cogentembedded.com" 
	<sergei.shtylyov@cogentembedded.com>,
	"bgolaszewski@baylibre.com" <bgolaszewski@baylibre.com>,
	"mika.westerberg@linux.intel.com"
	<mika.westerberg@linux.intel.com>,
	"efremov@linux.com" <efremov@linux.com>,
	"ztuowen@gmail.com" <ztuowen@gmail.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH v2] devres: keep both device name and resource name in pretty name
Date: Mon, 1 Jun 2020 13:39:46 +0300	[thread overview]
Message-ID: <CAHp75Vfg20sTa2qCQkA5g5uFzGtm7rGc9MuqpC4CSjU-4y0V9g@mail.gmail.com> (raw)
In-Reply-To: <CA+h21ho-XYzWo8BqHwu9REnBVEgG2Zynuux=j_UJ8hvhXATOVA@mail.gmail.com>

On Mon, Jun 1, 2020 at 12:13 AM Vladimir Oltean <olteanv@gmail.com> wrote:
> On Mon, 1 Jun 2020 at 00:05, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> > On Sunday, May 31, 2020, Vladimir Oltean <olteanv@gmail.com> wrote:

> >> Sometimes debugging a device is easiest using devmem on its register
> >> map, and that can be seen with /proc/iomem. But some device drivers have
> >> many memory regions. Take for example a networking switch. Its memory
> >> map used to look like this in /proc/iomem:
> >>
> >> 1fc000000-1fc3fffff : pcie@1f0000000
> >>   1fc000000-1fc3fffff : 0000:00:00.5
> >>     1fc010000-1fc01ffff : sys
> >>     1fc030000-1fc03ffff : rew
> >>     1fc060000-1fc0603ff : s2
> >>     1fc070000-1fc0701ff : devcpu_gcb
> >>     1fc080000-1fc0800ff : qs
> >>     1fc090000-1fc0900cb : ptp
> >>     1fc100000-1fc10ffff : port0
> >>     1fc110000-1fc11ffff : port1
> >>     1fc120000-1fc12ffff : port2
> >>     1fc130000-1fc13ffff : port3
> >>     1fc140000-1fc14ffff : port4
> >>     1fc150000-1fc15ffff : port5
> >>     1fc200000-1fc21ffff : qsys
> >>     1fc280000-1fc28ffff : ana
> >>
> >> But after the patch in Fixes: was applied, the information is now
> >> presented in a much more opaque way:
> >>
> >> 1fc000000-1fc3fffff : pcie@1f0000000
> >>   1fc000000-1fc3fffff : 0000:00:00.5
> >>     1fc010000-1fc01ffff : 0000:00:00.5
> >>     1fc030000-1fc03ffff : 0000:00:00.5
> >>     1fc060000-1fc0603ff : 0000:00:00.5
> >>     1fc070000-1fc0701ff : 0000:00:00.5
> >>     1fc080000-1fc0800ff : 0000:00:00.5
> >>     1fc090000-1fc0900cb : 0000:00:00.5
> >>     1fc100000-1fc10ffff : 0000:00:00.5
> >>     1fc110000-1fc11ffff : 0000:00:00.5
> >>     1fc120000-1fc12ffff : 0000:00:00.5
> >>     1fc130000-1fc13ffff : 0000:00:00.5
> >>     1fc140000-1fc14ffff : 0000:00:00.5
> >>     1fc150000-1fc15ffff : 0000:00:00.5
> >>     1fc200000-1fc21ffff : 0000:00:00.5
> >>     1fc280000-1fc28ffff : 0000:00:00.5
> >>
> >> That patch made a fair comment that /proc/iomem might be confusing when
> >> it shows resources without an associated device, but we can do better
> >> than just hide the resource name altogether. Namely, we can print the
> >> device name _and_ the resource name. Like this:
> >>
> >> 1fc000000-1fc3fffff : pcie@1f0000000
> >>   1fc000000-1fc3fffff : 0000:00:00.5
> >>     1fc010000-1fc01ffff : 0000:00:00.5 sys
> >>     1fc030000-1fc03ffff : 0000:00:00.5 rew
> >>     1fc060000-1fc0603ff : 0000:00:00.5 s2
> >>     1fc070000-1fc0701ff : 0000:00:00.5 devcpu_gcb
> >>     1fc080000-1fc0800ff : 0000:00:00.5 qs
> >>     1fc090000-1fc0900cb : 0000:00:00.5 ptp
> >>     1fc100000-1fc10ffff : 0000:00:00.5 port0
> >>     1fc110000-1fc11ffff : 0000:00:00.5 port1
> >>     1fc120000-1fc12ffff : 0000:00:00.5 port2
> >>     1fc130000-1fc13ffff : 0000:00:00.5 port3
> >>     1fc140000-1fc14ffff : 0000:00:00.5 port4
> >>     1fc150000-1fc15ffff : 0000:00:00.5 port5
> >>     1fc200000-1fc21ffff : 0000:00:00.5 qsys
> >>     1fc280000-1fc28ffff : 0000:00:00.5 ana

> > All of this seems an ABI change.

> Yes, indeed. What should I understand from your comment though?

You effectively break an ABI.

-- 
With Best Regards,
Andy Shevchenko

  reply	other threads:[~2020-06-01 10:40 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-31 18:07 [PATCH v2] devres: keep both device name and resource name in pretty name Vladimir Oltean
     [not found] ` <CAHp75Vc5NrDUZwv7uW+P=Ly+tz3a9XgEukX6ZgSccj_1sMYQaw@mail.gmail.com>
2020-05-31 21:13   ` Vladimir Oltean
2020-06-01 10:39     ` Andy Shevchenko [this message]
2020-06-01 10:43       ` Vladimir Oltean
2020-06-01  7:51 ` Sergei Shtylyov
2020-06-01  9:36   ` Vladimir Oltean
2020-06-01  9:48     ` Greg Kroah-Hartman

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