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charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: p-exch-cas-a-m1.sberdevices.ru (172.24.201.216) To p-exch-cas-s-m1.sberdevices.ru (172.16.210.2) X-KSMG-AntiPhishing: NotDetected, bases: 2026/02/13 10:48:00 X-KSMG-AntiSpam-Auth: dkim=none X-KSMG-AntiSpam-Envelope-From: gnstark@salutedevices.com X-KSMG-AntiSpam-Info: LuaCore: 87 0.3.87 7430d8ffafccd8879e1d8370e5b501352446c2ba, {Tracking_uf_ne_domains}, {Tracking_bl_eng_cat}, {Tracking_from_domain_doesnt_match_to}, salutedevices.com:7.1.1;elixir.bootlin.com:7.1.1;smtp.sberdevices.ru:5.0.1,7.1.1;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2;lkml.iu.edu:7.1.1, {Track_Chinese_Simplified}, FromAlignment: s X-KSMG-AntiSpam-Interceptor-Info: scan successful X-KSMG-AntiSpam-Lua-Profiles: 200473 [Feb 13 2026] X-KSMG-AntiSpam-Method: none X-KSMG-AntiSpam-Rate: 0 X-KSMG-AntiSpam-Status: not_detected X-KSMG-AntiSpam-Version: 6.1.1.20 X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 2.1.1.8310, bases: 2026/02/13 08:57:00 #28203847 X-KSMG-AntiVirus-Status: NotDetected, skipped X-KSMG-KATA-Status: Not Scanned X-KSMG-LinksScanning: NotDetected, bases: 2026/02/13 10:48:00 X-KSMG-Message-Action: skipped X-KSMG-Rule-ID: 5 On 2/10/26 01:31, Martin Blumenstingl wrote: > Hi George, > > sorry for the late reply. > > On Thu, Jan 29, 2026 at 3:48 PM George Stark wrote: Hello Martin. It's great to hear from you again. >> >> >> On 1/26/26 12:35, Nick Xie wrote: >>>> Thanks for the patch. Since you have khadas mail I'm pretty sure you've >>>> had the possibility to test it on the real vim board and I just don't >>>> get it how it works with the voltage table above. The problem is that >>>> pwm is calculated incorrectly in the upstream pwm-meson driver. That >>>> voltage table appeared to be used in early amlogic bl loader and >>>> appropriate pwm is initialized from a table's record. Duty cycle value >>>> is translated to pwm regs correctly. Later when kernel start running >>>> pwm-regulator driver is probed. It reads the pwm regs, calculates back >>>> duty-cyle and search it in the table. Since calculation algos are not >>>> match and the table doesn't contain full range of 0-100% values >>>> regulator driver doesn't find current voltage. In such case regulator >>>> core sets the minimum voltage from the table [1] and the SoC may hang >>>> (depending on board) due to minimum voltage may be too low for the >>>> current frequency SoC uses. > Nick likely didn't spot any issues on S4 since CPU frequency scaling > is not upstreamed yet (as there's no way to control the CPU clock > yet). > The lack of a OPP table means: the PWM and CPU clock will just stay at > whatever the bootloader provides It makes sense. I should experiment on the latest kernel. >>>> Or I'm missing something? >>> >>> >>>> There's not-yet-reviewed patch that fixes pwm algo [2]. There's >>>> calculation example in the cover letter. >>>> [1] https://elixir.bootlin.com/linux/v6.19-rc5/source/drivers/regulator/core.c#L1227 >>>> [2] https://lkml.iu.edu/2412.3/00826.html >>> >>> What's the status of such patches? >> >> the patch is ready for review. It's seems like nobody is interested > I'm sorry to see that the patch had it's first anniversary. > I'll need to bring out my logic analyzer and test your patch (I hope > it's precise enough to show the impact of your changes). > Are your plans then to re-send the patches or have you moved on and > need someone else to take care of it? It's a major step anyway if you confirm the issue yourself with an analyzer. In that case discussion won't be delayed for one more year I think. Thanks. Sure I'm ready to discuss/fix/resend this patch. -- Best regards George