Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 09 Apr 2018 15:17:09 +0200
Message-ID: <s5h1sfoh63u.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     "Jia-Ju Bai" <baijiaju1990@gmail.com>
Cc:     <T-Bone@parisc-linux.org>, <perex@perex.cz>,
        <alsa-devel@alsa-project.org>, <linux-kernel@vger.kernel.org>,
        <linux-parisc@vger.kernel.org>
Subject: Re: [PATCH 1/2] sound: ad1889: Replace mdelay with usleep_range in snd_ad1889_init
In-Reply-To: <1523279000-23973-1-git-send-email-baijiaju1990@gmail.com>
References: <1523279000-23973-1-git-send-email-baijiaju1990@gmail.com>
User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka)
 FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3
 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO)
MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka")
Content-Type: text/plain; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, 09 Apr 2018 15:03:20 +0200,
Jia-Ju Bai wrote:
> 
> snd_ad1889_init() is never called in atomic context.
> 
> The call chain ending up at snd_ad1889_init() is:
> [1] snd_ad1889_init() <- snd_ad1889_create() <- snd_ad1889_probe()
> 
> snd_ad1889_probe() is only set as ".probe" in struct pci_driver.
> This function is not called in atomic context.
> 
> Despite never getting called from atomic context, snd_ad1889_init()
> calls mdelay for busy wait.
> This is not necessary and can be replaced with usleep_range to
> avoid busy waiting.
> 
> This is found by a static analysis tool named DCNS written by myself.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>

Since it's no urgent fix, I'll postpone to 4.18.


thanks,

Takashi