From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lucas Stach Subject: Re: [PATCH 3/6] drm: tegra: protect DC register access with mutex Date: Thu, 20 Dec 2012 09:28:25 +0100 Message-ID: <1355992105.1490.79.camel@tellur> References: <1355953137-31563-1-git-send-email-dev@lynxeye.de> <1355953137-31563-4-git-send-email-dev@lynxeye.de> <50D2799F.4010008@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50D2799F.4010008-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Zhang Cc: dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Thierry Reding , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org Am Donnerstag, den 20.12.2012, 10:36 +0800 schrieb Mark Zhang: > OK, you add a mutex in a tegra_dc structure. But I think there is no > parallel scenario while we operate on a dc. AFAIK, the functions which > you add mutex protection are called by drm sequentially(except for > function "tegra_crtc_load_lut" I'm not very clear about that). > > So could you give us an example? > You are right, I looked this up again. I thought cursor actions are async to other modeset actions, but in fact they are also protected by the mode_config.mutex. So really no need to have another mutex in our dc code. Sorry for the noise. Lucas