> -----Original Message----- > From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> > Sent: Tuesday, December 14, 2021 10:36 AM > To: Neal Liu <neal_liu@xxxxxxxxxxxxxx>; Felipe Balbi <balbi@xxxxxxxxxx>; > Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Joel Stanley > <joel@xxxxxxxxx>; Andrew Jeffery <andrew@xxxxxxxx>; Cai Huoqing > <caihuoqing@xxxxxxxxx>; Tao Ren <rentao.bupt@xxxxxxxxx>; Julia Lawall > <julia.lawall@xxxxxxxx>; kernel test robot <lkp@xxxxxxxxx>; Sasha Levin > <sashal@xxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-aspeed@xxxxxxxxxxxxxxxx > Cc: BMC-SW <BMC-SW@xxxxxxxxxxxxxx> > Subject: Re: [PATCH v3 2/4] usb: aspeed-vhub: fix remote wakeup failure in > iKVM use case > > On Thu, 2021-12-09 at 02:37 +0000, Neal Liu wrote: > > I'm confused. Signaling Wakeup when wakeup_en is set if it has any ep > > activities is not exactly what you said? > > > > wakeup_en is set only if host allows this device have wakeup > > capability and bus being suspended. > > > > Normal ep activities would not write the MMIO because wakeup_en is not > > set. > > Hrm... I didn't think wakeup_en was limited to the bus being suspended, but > maybe I misremember, it's been a while. > > Cheers, > Ben. > wakeup_en is only set in the case of host set USB_DEVICE_REMOTE_WAKEUP feature to vhub devices. I think this behavior only occurs during host is going to suspend, and set this feature to any device which can wakeup itself before sleep. Thanks -Neal
