From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] ARM: tegra: don't unlock MMIO access to DBGLAR Date: Wed, 06 Mar 2013 13:42:21 -0700 Message-ID: <5137AA2D.6000401@wwwdotorg.org> References: <1361268973-14584-1-git-send-email-josephl@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1361268973-14584-1-git-send-email-josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Joseph Lo Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 02/19/2013 03:16 AM, Joseph Lo wrote: > There is no need to unlock MMIO access to the DBGLAR all the time. Doing > so may even cause problems if a SW bug causes writes to that MMIO region. > > Cortex-A15 processors do not support the CP14 register write the code > currently uses to unlock the DBGLAR; the instruction throws an undefined > instruction exceptions. This prevents tegra_secondary_startup() from > executing on Tegra114, and hence prevents SMP. > > Remove the code that unlocks this access. I have applied this to Tegra's for-3.10/fixes branch.