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Date:   Wed, 15 Dec 2021 22:04:41 +0100
From:   Marek =?UTF-8?B?QmVow7pu?= <kabel@kernel.org>
To:     Pavel Machek <pavel@ucw.cz>
Cc:     Dan Carpenter <dan.carpenter@oracle.com>,
        simon.guinot@sequanux.org, linux-leds@vger.kernel.org,
        j.anaszewski@samsung.com
Subject: Re: [bug report] leds: ns2: Remove work queue
Message-ID: <20211215220441.2d83299a@thinkpad>
In-Reply-To: <20211215203955.GG28336@duo.ucw.cz>
References: <20211210135249.GA16777@kili>
        <20211215203955.GG28336@duo.ucw.cz>
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On Wed, 15 Dec 2021 21:39:55 +0100
Pavel Machek <pavel@ucw.cz> wrote:

> Hi!
> 
> > Hello LED devs,
> > 
> > The patch c29e650b3af2: "leds: ns2: Remove work queue" from Nov 20,
> > 2015, leads to the following Smatch static checker warning:
> > 
> > 	drivers/leds/leds-ns2.c:96 ns2_led_set_mode()
> > 	warn: sleeping in atomic context  
> 
> Yup, this looks wrong.
> 
> Plus, the code is quite crazy.
> 
> Not sure what the write_lock in that function is supposed to protect
> against. Perhaps it can be just removed?
> 
> Hmm. led_set_mode uses custom interface for hardware accelerated
> LED. Ideally there's more fixing to be done there :-(.

The last time we discussed this, Simon said that he is willing to
convert once we have trigger offloading API. But we will also need
blkdev trigger. Time to review Ian Pilcher's last attempt at blkdev?
  [RESEND PATCH v8 0/2] Introduce block device LED trigger
  https://lore.kernel.org/linux-leds/20211119212733.286427-1-arequipeno@gmail.com/

Marek