From mboxrd@z Thu Jan 1 00:00:00 1970 From: heiko@sntech.de (Heiko Stuebner) Date: Mon, 26 Sep 2016 22:18:42 +0200 Subject: [PATCH] soc: rockchip: power-domain: Don't (incorrectly) set rk3399 up/down counts In-Reply-To: <1471546561-4459-1-git-send-email-dianders@chromium.org> References: <1471546561-4459-1-git-send-email-dianders@chromium.org> Message-ID: <3409868.mFCNHRg95O@phil> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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: > * 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 . > > Signed-off-by: Douglas Anderson applied to my drivers branch for 4.10 Thanks Heiko