From mboxrd@z Thu Jan 1 00:00:00 1970 From: sudeep.holla@arm.com (Sudeep Holla) Date: Thu, 30 Mar 2017 16:47:59 +0100 Subject: [PATCH v5 6/9] coresight: add support for CPU debug module In-Reply-To: References: <1490466197-29163-1-git-send-email-leo.yan@linaro.org> <1490466197-29163-7-git-send-email-leo.yan@linaro.org> <20170328165010.GA21937@linaro.org> <20170329015423.GA5035@leoy-linaro> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 29/03/17 15:56, Mike Leach wrote: [...] > > No - EDPRCR_COREPURQ and EDPRCR_CORENPDRQ have different semantics and purposes > > EDPRCR_COREPURQ is in the debug power domain an is tied to an external > debug request that should be an input to the external (to the PE) > system power controller. > The requirement is that the system power controller powers up the core > domain and does not power it down while it remains asserted. > > EDPRCR_CORENPDRQ is in the core power domain and thus to the specific > core only. This ensures that any power control software running on > that core should emulate a power down if this is set to one. > > We cannot know the power control design of the system, so the safe > solution is to set both bits. > +1 I agree that's the safe bet. -- Regards, Sudeep