From mboxrd@z Thu Jan  1 00:00:00 1970
From: Takashi Iwai <tiwai-l3A5Bk7waGM@public.gmane.org>
Subject: Re: [alsa-devel] [PATCH] ASoC: tegra: Use flat regcache.
Date: Tue, 18 Mar 2014 11:33:09 +0100
Message-ID: <s5h4n2vssnu.wl%tiwai@suse.de>
References: <1395115139-22243-1-git-send-email-dgreid@chromium.org>
	<s5hha6wdmxa.wl%tiwai@suse.de>
	<20140318102858.GE11706@sirena.org.uk>
Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka")
Content-Type: text/plain; charset=US-ASCII
Return-path: <linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
In-Reply-To: <20140318102858.GE11706-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
To: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Dylan Reid <dgreid-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>, alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org
List-Id: alsa-devel@alsa-project.org

At Tue, 18 Mar 2014 10:28:58 +0000,
Mark Brown wrote:
> 
> On Tue, Mar 18, 2014 at 07:46:09AM +0100, Takashi Iwai wrote:
> 
> > kmemdup() with GFP_KERNEL in the lock context.  Ditto in
> > regmap_register_patch(), which calls krealloc() with GFP_KERNEL.
> 
> So send a patch...

Yeah, yeah, don't rush :)

> > The former could be fixed by moving the lock like below.  The fix for
> > the latter depends on whether we need to protect map->patch_regs
> > growth from races or not.  If not, krealloc() can be moved out of the
> > lock.
> 
> It should only be happening on init so probably not.  On the other hand
> doing it without any sort of locking isn't great.

Right.  OTOH, it's still better than papering over with GFP_ATOMIC, I
think.  We can just give a proper note in the function description,
for example.


Takashi