From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko Stuebner Subject: Re: [PATCH] soc: rockchip: power-domain: Don't (incorrectly) set rk3399 up/down counts Date: Fri, 19 Aug 2016 00:03:01 +0200 Message-ID: <86565478.t9HNV2EDZM@phil> References: <1471546561-4459-1-git-send-email-dianders@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1471546561-4459-1-git-send-email-dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+glpar-linux-rockchip=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Douglas Anderson Cc: zhangqing-TNX95d0MmH7DzftRWevZcw@public.gmane.org, zhengxing-TNX95d0MmH7DzftRWevZcw@public.gmane.org, shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org, dbasehore-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, wxt-TNX95d0MmH7DzftRWevZcw@public.gmane.org List-Id: linux-rockchip.vger.kernel.org Hi Doug, Am Donnerstag, 18. August 2016, 11:56:01 CEST schrieb Douglas Anderson: > On rk3288 it was important that powerdown and powerup counts for the > CPU/GPU in the kernel because: somehow this sentence seems to miss some verb or so :-) > * The power on default was crazy long. > * We couldn't rely on the firmware to set this up because really this > wasn't the firmware's job--the kernel was the only one that really > cared about bringing up / down CPUs and the GPU and doing suspend / > resume (which involves bringing up / down CPUs). > > On newer ARM systems (like rk3399) ARM Trusted Firmware is in charge of > bringing up and down the CPUs and it really should be in charge of > setting all these counts right. After all ATF is in charge of suspend / > resume and CPU up / down. Let's get out of the way and let ATF do its > job. > > A few other motivations for doing this: > * Depending on another configuration (PMU_24M_EN_CFG) these counts can > be either in 24M or 32k cycles. Thus, though ATF isn't really so > involved in bringing up the GPU, ATF should probably manage the counts > for everything so it can also manage the 24M / 32k choice. > * It turns out that (right now) 24M mode is broken on rk3399 and not > being used. That means that the count the kernel was programming > in (24) was not 1 us (which it seems was intended) but was actually > .75 ms > * On rk3399 there are actually 2 separate registers for setting CPU > up/down time plus 1 register for GPU up/down time. The curent kernel > code actually was putting the register for the "little" cores in the > "CPU" slot and the register for the "big" cores in the "GPU" slot. It > was never initting the GPU counts. > > Note: this change assumes that ATF will actually set these values at > boot, as I'm proposing in . I'd hope to see a link to an ATF github pull request here :-) But I guess that simply needs some more discussion on your side. > Signed-off-by: Douglas Anderson change itself looks good to me. So I guess we'll just need to wait for the counterpart to land in the ATF or do you know if the poweron-defaults are somewhat sane? Heiko