From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Kaehlcke Subject: Re: [PATCH v4 2/6] remoteproc/mediatek: add SCP support for mt8183 Date: Wed, 13 Feb 2019 09:01:05 -0800 Message-ID: <20190213170105.GX117604@google.com> References: <20190131093131.245531-1-pihsun@chromium.org> <20190131093131.245531-3-pihsun@chromium.org> <20190202001749.GT81583@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Pi-Hsun Shih Cc: Erin Lo , Nicolas Boichat , Ohad Ben-Cohen , Bjorn Andersson , Matthias Brugger , open list , "open list:REMOTE PROCESSOR (REMOTEPROC) SUBSYSTEM" , "moderated list:ARM/Mediatek SoC support" , "moderated list:ARM/Mediatek SoC support" List-Id: linux-mediatek@lists.infradead.org On Wed, Feb 13, 2019 at 11:20:18AM +0800, Pi-Hsun Shih wrote: > Hi, > > Thanks for the review, would address most comments in next version of patch. > > On Sat, Feb 2, 2019 at 8:17 AM Matthias Kaehlcke wrote: > > > > Hi Pi-Hsun, > > > > a few comments inline. > > > > It's the first time I dabble into remoteproc, I don't claim to have a > > complete understanding of the driver at this point ;-) > > > > On Thu, Jan 31, 2019 at 05:31:27PM +0800, Pi-Hsun Shih wrote: > > > diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c > > > new file mode 100644 > > > index 00000000000000..920c81c3525c2a > > > --- /dev/null > > > +++ b/drivers/remoteproc/mtk_scp.c > > > + return ret; > > > + } > > > + > > > + writel(0x0, scp->reg_base + MT8183_SCP_SRAM_PDN); > > > > what is the purpose of this write? > > > > Answer from Erin: > The code needs to execute on scp’s SRAM. > We need to turn on the power of SRAM before using it. Please add a brief comment since this is not evident from the code. Thanks Matthias