From mboxrd@z Thu Jan 1 00:00:00 1970 From: sudeep.holla@arm.com (Sudeep Holla) Date: Mon, 4 Dec 2017 02:24:06 +0000 Subject: SCPI regressions in v4.15-rc1 on Amlogic SoCs. In-Reply-To: References: Message-ID: <20171204022406.GA6870@e107533-lin> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Nov 30, 2017 at 04:21:13PM -0800, Kevin Hilman wrote: > Hi Sudeep, > > There's been a pretty major regression in v4.15-rc1 compared to v4.15 > in SCPI causing warning splats on amlogic SoCs when cpufreq starts up > and tries to set the OPP for the first time[1]. > Looks like some issue with firmware we are hitting. I assume CPUFreq was never initialised on this platform before(i.e. v4.14) and these changes are changing the probe path, so it could be that change causing the regression. > I ran out of time to narrow it down further since there have been > quite a few changes since v4.14, but simply reverting > drivers/firmware/arm_scpi.c to its v4.14 state gets things working > again. > Makes sense. > This has been happening for awhile, and we should've caught it sooner > in kernelCI.org, however this warning splat still allows the kernel to > finish booting, so it still resulted in a PASS for the boot test. > That combined with the fact that we've been tracking some other > regressions, we didn't notice it until now. > It's unfortunate that it didn't get tested in linux-next as it was pulled a while a ago. > Also, is this the expected result for the pre-1.0 firmware: > > scpi_protocol scpi: SCP Protocol 0.0 Firmware 0.0.0 version > I think so, since Amlogic has unreleased/draft version of the specification implemented, we did discuss to print something similar in the past. -- Regards, Sudeep