Hi Stefan, On 9/5/2018 10:42 PM, Stefan Wahren wrote: > Hi Minas, > >> Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx> hat am 5. September 2018 um 10:37 geschrieben: >> >> >> Hi Stefan, >> >> On 9/1/2018 1:55 PM, Stefan Wahren wrote: >>> Currently USB consumes a lot of power after shutting down a Raspberry Pi 3 >>> (example setup with Ethernet and a keyboard connected). So power off >>> USB on shutdown. >>> >>> Measured on Raspberry Pi 3B with 4.19rc1/multi_v7_defconfig (HDMI, Ethernet >>> and a keyboard connected) >>> >>> Before patch: 2.450 W >>> After patch: 2.090 W >>> >> >> Could you please elaborate. Power measurements done after shutdown? > > I did the following: > > sudo halt > wait until "System halted" appears on the screen > "measured" the current value displayed on my PSU > > You are right that not the same as poweroff. But in even in poweroff the board consumes 0.6 W, but in this case USB is powered down. > >> Why >> your setup continue consume power after shutdown? > > The BCM2835 SoC has a GPU and a ARM core. Linux is running only on the ARM core. The GPU is usually running a close source firmware, which is started at first during boot und runs all the time. > >> Maybe its >> sleep/hibernation mode? > > There isn't much implementation of power management for BCM2835 yet. So i wanted to start with USB. > Even for sleep/hibernation the consumption is much too high. Because the system consumes in idle 1.6 W. > >> >> dwc2 core in your platform which type of power optimization supports: >> partial power down, hibernation or extended hibernation? Please provide >> me GHWCFG4 register value of your core. > > AFAIK all RPis use the same USB IP core: > > GHWCFG4 = 0x1ff00020 Ok, your core doesn't support any power optimization mode. > > Stefan > 1. Could you please explain what is real/physical cause of power saving after your patch: VBUS off, PHY clock stop or any other? 2. Can USB detect remote wake-up signaling from connected keyboard/ethernet before and after your patch? Thanks, Minas
