On Thu, Jul 1, 2021 at 12:42 AM Marek Behun <[email protected]> wrote: > > On Wed, 30 Jun 2021 17:51:24 +0200 > Robert Marko <[email protected]> wrote: > > > On Wed, Jun 30, 2021 at 3:19 PM Marek Behún <[email protected]> wrote: > > > > > > Hello Robert, > > > > > > I am writing regarding commit > > > mvebu: 5.10 fix DVFS caused random boot crashes > > > > > > https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=080a0b74e39d159eecf69c468debec42f28bf4d8 > > > in OpenWRT. > > > > > > This commit reverts the one patch of a3720 cpufreq driver, but not > > > the subsequent ones. > > > > > > Your commit message says that some 1.2 GHz SOCs are unstable with the > > > fix. Did you also test this with the subsequent patches, which are now > > > in stable kernels? I guess the answer is yes, because all these patches > > > were backported to 5.10.37. > > > > Hi Marek, > > > > Yes, the rest of the patches were there as well. > > > > > > I am of the opinion that a better approach would be to > > > - either disable cpufreq for 1.2 GHz variants > > > - fix a3720 cpufreq driver to only scale up to 1 GHz on 1.2 GHz variant > > > > I would prefer limiting it to 1GHz as that would not cause performance > > issues, > > but 1GHz models could have the same issue as well. > > This is because the voltages that are set as a minimum are from the testing > > that > > Pali and the Turris guys did, but it really depends on the SoC batch > > you receive. > > > > > > Since the approach you've taken now (reverting the patch) basically > > > changes the CPU parnet clock to DDR clock, which is just wrong. > > > Worse is that you are doing this for everybody, not just for the 1.2 > > > GHz variants. > > > > > > What do you think? > > > > I understand that it was not the best solution, but something had to be > > done as > > I was not able to even finish booting on multiple boards before crashing. > > It just reverted the things back to the previous state. > > > > I really could not figure a proper solution even after being in touch > > with Pali, and contacting > > GlobalScale. > > > > This is an issue caused by Marvell simply ignoring the issue and > > refusing to publish > > a fix or release the OTP and AVS docs as they all have a validated > > voltage in the OTP > > somewhere. > > Robert, we've found this table in linux-marvell repository: > > https://github.com/MarvellEmbeddedProcessors/linux-marvell/blob/dc33b62c90696afb6adc7dbcc4ebbd48bedec269/drivers/regulator/armada-37xx-regulator.c#L99-L105 > > Do you still have the 1.2 GHz boards which were crashing? Would you be > willing to test whether those boards are stable if we provided patch > for you?
Yes, I tested on 4 boards If I remember correctly and they all crashed with the voltages that are set, only by manually raising to at least 1.1902V one got stable while other required 1.2+V I would be glad to test a possible solution. Regards, Robert > > Marek -- Robert Marko Staff Embedded Linux Engineer Sartura Ltd. Lendavska ulica 16a 10000 Zagreb, Croatia Email: [email protected] Web: www.sartura.hr _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/mailman/listinfo/openwrt-devel
