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From: "Marek Behún" <kabel@kernel.org>
To: Pavel Machek <pavel@ucw.cz>
Cc: Da Xue <da@libre.computer>,
	lee@kernel.org, sashal@kernel.org, linux-leds@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-stable <stable@vger.kernel.org>
Subject: Re: linux-stable 6.1.53 kernel crash on COLOR_ID_MULTI handling change
Date: Mon, 18 Sep 2023 16:11:33 +0200	[thread overview]
Message-ID: <20230918161133.4c32a0e6@dellmb> (raw)
In-Reply-To: <ZQLelWcNjjp2xndY@duo.ucw.cz>

On Thu, 14 Sep 2023 12:21:09 +0200
Pavel Machek <pavel@ucw.cz> wrote:

> Hi!
> 
> > We have running systems that use COLOR_ID_MULTI. The GPIO toggles
> > between two colors and we have used the identifier. RGB is not a good
> > fit since it is not a RGB LED. Please provide guidance.
> > 
> > This patch causes the system to not start: f741121a2251 leds: Fix
> > BUG_ON check for LED_COLOR_ID_MULTI that is always false
> > 
> > It was also backported to stable causing previously booting systems to
> > no longer boot.  
> 
> Lets cc patch authors.
> 
> And please drop this from stable, it does not belong there.
> 
> Best regards,
> 								Pavel

The BUG_ON was a no-op since it was introduced. It's purpose was to
prevent people from using LED_COLOR_ID_MULTI since it was thought that
non-RGB LEDs are not yet completely agreed on, or something.

But since the BUG_ON was a no-op, someone started using
LED_COLOR_ID_MULTI without noticing that they should not. There are now
even some in-tree device-tree files using LED_COLOR_ID_MULTI.

My patch that fixes the BUG_ON uncovered this and caused a regression
for some people.

I think we have to drop the BUG_ON altoghether now.

I've sent a patch to linux-leds doing just that.

Sorry for the incovenience.

Marek

      reply	other threads:[~2023-09-18 16:45 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-13 18:57 linux-stable 6.1.53 kernel crash on COLOR_ID_MULTI handling change Da Xue
2023-09-14 10:21 ` Pavel Machek
2023-09-18 14:11   ` Marek Behún [this message]

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