Re: [GIT PULL] immutable branch for amba changes targeting v5.12-rc1 - Uwe Kleine-König

From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-fbdev@vger.kernel.org,
	"Dmitry Torokhov" <dmitry.torokhov@gmail.com>,
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	"Jaroslav Kysela" <perex@perex.cz>,
	"Eric Anholt" <eric@anholt.net>,
	"Uwe Kleine-König" <u.kleine-koenig.org@pengutronix.de>,
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Subject: Re: [GIT PULL] immutable branch for amba changes targeting v5.12-rc1
Date: Fri, 5 Feb 2021 10:37:44 +0100	[thread overview]
Message-ID: <20210205093744.kr4rc7yvfiq6wimq@pengutronix.de> (raw)
In-Reply-To: <20210204181551.ethtuzm65flujmwe@pengutronix.de>

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Hello Russell, hello Greg,

On Thu, Feb 04, 2021 at 07:15:51PM +0100, Uwe Kleine-König wrote:
> On Thu, Feb 04, 2021 at 04:59:51PM +0000, Russell King - ARM Linux admin wrote:
> > On Thu, Feb 04, 2021 at 05:56:50PM +0100, Greg Kroah-Hartman wrote:
> > > On Thu, Feb 04, 2021 at 04:52:24PM +0000, Russell King - ARM Linux admin wrote:
> > > > On Tue, Feb 02, 2021 at 03:06:05PM +0100, Greg Kroah-Hartman wrote:
> > > > > I'm glad to take this through my char/misc tree, as that's where the
> > > > > other coresight changes flow through.  So if no one else objects, I will
> > > > > do so...
> > > > 
> > > > Greg, did you end up pulling this after all? If not, Uwe produced a v2.
> > > > I haven't merged v2 yet as I don't know what you've done.
> > > 
> > > I thought you merged this?
> > 
> > I took v1, and put it in a branch I've promised in the past not to
> > rebase/rewind. Uwe is now asking for me to take a v2 or apply a patch
> > on top.
> > 
> > The only reason to produce an "immutable" branch is if it's the basis
> > for some dependent work and you need that branch merged into other
> > people's trees... so the whole "lets produce a v2" is really odd
> > workflow... I'm confused about what I should do, and who has to be
> > informed which option I take.
> > 
> > I'm rather lost here too.
> 
> Sorry to have cause this confusion. After I saw that my initial tag
> missed to adapt a driver I wanted to make it easy for you to fix the
> situation.
> So I created a patch to fix it and created a second tag with the patch
> squashed in. Obviously only one of them have to be picked and I hoped
> you (= Russell + Greg) would agree which option to pick.
> 
> My preference would be if you both pick up v2 of the tag to yield a
> history that is bisectable without build problems, but if Russell (who
> already picked up the broken tag) considers his tree immutable and so
> isn't willing to rebase, then picking up the patch is the way to go.

OK, the current state is that Russell applied the patch fixing
drivers/mailbox/arm_mhuv2.c on top of merging my first tag.

So the way forward now is that Greg pulls

	git://git.armlinux.org.uk/~rmk/linux-arm.git devel-stable

which currently points to 

	860660fd829e ("ARM: 9055/1: mailbox: arm_mhuv2: make remove callback return void")

, into his tree that contains the hwtracing changes that conflict with my
changes. @Greg: Is this good enough, or do you require a dedicated tag
to pull that?

I think these conflicting hwtracing changes are not yet in any of Greg's
trees (at least they are not in next).

When I pull

	https://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git next

(currently pointing to 4e73ff249184 ("coresight: etm4x: Handle accesses
to TRCSTALLCTLR")) into 860660fd829e, I get a conflict in
drivers/hwtracing/coresight/coresight-etm4x-core.c as expected. My
resolution looks as follows:

diff --cc drivers/hwtracing/coresight/coresight-etm4x-core.c
index 82787cba537d,5017d33ba4f5..000000000000

--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@@ -1703,6 -1906,28 +1906,27 @@@ static int __exit etm4_remove_dev(struc
  	cpus_read_unlock();
  
  	coresight_unregister(drvdata->csdev);
+ 
+ 	return 0;
+ }
+ 
 -static int __exit etm4_remove_amba(struct amba_device *adev)
++static void __exit etm4_remove_amba(struct amba_device *adev)
+ {
+ 	struct etmv4_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+ 
+ 	if (drvdata)
 -		return etm4_remove_dev(drvdata);
 -	return 0;
++		etm4_remove_dev(drvdata);
+ }
+ 
+ static int __exit etm4_remove_platform_dev(struct platform_device *pdev)
+ {
+ 	int ret = 0;
+ 	struct etmv4_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
+ 
+ 	if (drvdata)
+ 		ret = etm4_remove_dev(drvdata);
+ 	pm_runtime_disable(&pdev->dev);
+ 	return ret;
  }
  
  static const struct amba_id etm4_ids[] = {

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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