Re: [RFC][PATCH] drm: kirin: Fix dsi probe/attach logic

From: Andrzej Hajda <a.hajda@samsung.com>
To: John Stultz <john.stultz@linaro.org>
Cc: Rob Clark <robdclark@gmail.com>,
	Jernej Skrabec <jernej.skrabec@siol.net>,
	Jonas Karlman <jonas@kwiboo.se>, David Airlie <airlied@linux.ie>,
	Neil Armstrong <narmstrong@baylibre.com>,
	lkml <linux-kernel@vger.kernel.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	Xinliang Liu <z.liuxinliang@hisilicon.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Sean Paul <seanpaul@chromium.org>,
	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
	Rongrong Zou <zourongrong@gmail.com>,
	Sam Ravnborg <sam@ravnborg.org>,
	Matt Redfearn <matt.redfearn@thinci.com>
Subject: Re: [RFC][PATCH] drm: kirin: Fix dsi probe/attach logic
Date: Wed, 4 Sep 2019 12:26:05 +0200	[thread overview]
Message-ID: <9d31af23-8a65-d8e8-b73d-b2eb815fcd6f@samsung.com> (raw)
In-Reply-To: <CALAqxLU5Ov+__b5gxnuMxQP1RLjndXkB4jAiGgmb-OMdaKePug@mail.gmail.com>

On 03.09.2019 18:18, John Stultz wrote:
> On Mon, Sep 2, 2019 at 6:22 AM Andrzej Hajda <a.hajda@samsung.com> wrote:
>> On 30.08.2019 19:00, Rob Clark wrote:
>>> On Thu, Aug 29, 2019 at 11:52 PM Andrzej Hajda <a.hajda@samsung.com> wrote:
>>>> Of course it seems you have different opinion what is the right thing in
>>>> this case, so if you convince us that your approach is better one can
>>>> revert the patch.
>>> I guess my strongest / most immediate opinion is to not break other
>>> existing adv75xx bridge users.
>>
>> It is pity that breakage happened, and next time we should be more
>> strict about testing other platforms, before patch acceptance.
>>
>> But reverting it now will break also platform which depend on it.
> I'm really of no opinion of which approach is better here, but I will
> say that when a patch breaks previously working boards, that's a
> regression and justifying that some other board is now enabled that
> would be broken by the revert (of a patch that is not yet upstream)
> isn't really a strong argument.
>
> I'm happy to work with folks to try to fixup the kirin driver if this
> patch really is the right approach, but we need someone to do the same
> for the db410c, and I don't think its fair to just dump that work onto
> folks under the threat of the board breaking.

These drivers should be fixed anyway - assumption that
drm_bridge/drm_panel will be registered before the bus it is attached to
is just incorrect.

So instead of reverting, fixing and then re-applying the patch I have
gently proposed shorter path. If you prefer long path we can try to go
this way.

Matt, is the pure revert OK for you or is it possible to prepare some
workaround allowing cooperation with both approaches?

Regards

Andrzej

>
> thanks
> -john
>
>