linux-kernel - Re: [PATCH 4.4 16/34] led: core: Fix brightness setting when setting delay

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Date:   Thu, 8 Mar 2018 21:48:08 +0100
From:   Jacek Anaszewski <jacek.anaszewski@...il.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Ben Hutchings <ben.hutchings@...ethink.co.uk>,
        linux-kernel@...r.kernel.org, linux-leds@...r.kernel.org,
        Matthieu CASTET <matthieu.castet@...rot.com>,
        stable@...r.kernel.org
Subject: Re: [PATCH 4.4 16/34] led: core: Fix brightness setting when setting
 delay_off=0

On 03/08/2018 06:24 PM, Greg Kroah-Hartman wrote:
> On Wed, Mar 07, 2018 at 09:39:08PM +0100, Jacek Anaszewski wrote:
>> Hi Ben,
>>
>> On 03/07/2018 04:32 PM, Ben Hutchings wrote:
>>> On Fri, 2018-03-02 at 09:51 +0100, Greg Kroah-Hartman wrote:
>>>> 4.4-stable review patch.  If anyone has any objections, please let me
>>>> know.
>>>>
>>>> ------------------
>>>>
>>>> From: Matthieu CASTET <matthieu.castet@...rot.com>
>>>>
>>>>
>>>> [ Upstream commit 2b83ff96f51d0b039c4561b9f95c824d7bddb85c ]
>>>>
>>>> With the current code, the following sequence won't work :
>>>> echo timer > trigger
>>>>
>>>> echo 0 >  delay_off
>>>> * at this point we call
>>>> ** led_delay_off_store
>>>> ** led_blink_set
>>> [...]
>>>
>>> The commit message got cut truncated here, which resulted in addresses
>>> being omitted when it was sent out for review.  The upstream commit
>>> message refers to a LED_BLINK_SW flag which is not used in 4.4.  So
>>> this fix probably isn't needed, though I can't tell whether it does any
>>> harm.
>>
>> We discussed it in [0]. This patch is not needed for 4.4 and what's
>> more more it is harmful. It introduces a bug, fixed in [1].
>>
>> [0] https://lkml.org/lkml/2018/2/6/726
>> [1[ https://patchwork.kernel.org/patch/10253933/
> 
> So, did I mess something up here?  Am I missing some patch that I need
> to apply, or do I need to revert something?
> 
> confused,

It needs to be reverted in 4.4-stable, and Ben's patch [0] does what's
needed.

[0] https://www.spinics.net/lists/stable/msg223656.html

-- 
Best regards,
Jacek Anaszewski