Hi, On 2/25/22 17:19, Limonciello, Mario wrote: > [Public] > >> On 2/25/22 17:04, Limonciello, Mario wrote: >>> [Public] >>> >>>> On Fri, Feb 25, 2022 at 12:11:11AM -0600, Mario Limonciello wrote: >>>>> This board definition was originally created for mobile devices to >>>>> designate default link power managmeent policy to influence runtime >>>>> power consumption. >>>>> >>>>> As this is interesting for more than just mobile designs, rename the >>>>> board to `board_ahci_low_power` to make it clear it is about default >>>>> policy. >>>> >>>> Is there any good reason to not just apply the policy to all devices >>>> by default? >>> >>> That sure would make this all cleaner. >>> >>> I think Hans knows more of the history here than anyone else. I had >>> presumed there was some data loss scenarios with some of the older >>> chipsets. >> >> When I first introduced this change there were reports of crashes and >> data corruption caused by setting the policy to min_power, these were >> tied to some motherboards and/or to some drives. >> >> This is the whole reason why I only enabled this on a subset of all the >> AHCI chipsets. >> >> At least on devices with a chipset which is currently marked as >> mobile, the motherboard specific issues could be fixed with a BIOS >> update. But I doubt that similar BIOS fixes have also been rolled >> out to all desktop boards (and have been applied by all users), >> and I also don't know about older boards. >> >> So enabling this on all chipsets is definitely not without risks. >> > > This was before min_power_with_partial and min_power_with_dipm > were introduced though right? The issues where some laptops needed BIOS updates was with fedora using min_power_with_dipm as default for mobile chipsets. > Maybe another way to look at this > is to drop the policy min_power, which overall is dangerous. Maybe, see above. I'm not going to block this if people want to give this a try, but it is going to require someone keeping a very close look at any issues popping up and we must be prepared to roll-back the change if necessary. Regards, Hans
