Hi Paul, I think you need this patch to fix the problem: usb: dwc2: resume root hub when device detect with suspend state https://patchwork.kernel.org/patch/5325111/ Thanks, - Kever On 01/06/2015 09:23 AM, Paul Zimmerman wrote: >> From: Kever Yang [mailto:kever.yang at rock-chips.com] >> Sent: Wednesday, November 12, 2014 4:42 PM >> >> On 11/13/2014 07:22 AM, Doug Anderson wrote: >>> Kever, >>> >>> On Mon, Nov 10, 2014 at 5:09 AM, Kever Yang <kever.yang at rock-chips.com> wrote: >>>> Hcd controller needs bus_suspend/resume, dwc2 controller make >>>> root hub generate suspend/resume signal with hprt0 register >>>> when work in host mode. >>>> After the root hub enter suspend, we can make controller enter >>>> low power state with PCGCTL register. >>>> >>>> We also update the lx_state for hsotg state. >>>> >>>> This patch has tested on rk3288 with suspend/resume. >>>> >>>> Signed-off-by: Kever Yang <kever.yang at rock-chips.com> >>>> Acked-by: Paul Zimmerman <paulz at synopsys.com> >>>> --- >>>> >>>> Changes in v3: >>>> - remove CONFIG_PM macro for bus_suspend/resume >>>> - add PCGCTL operation for no device connect case >>>> >>>> Changes in v2: >>>> - update commit message >>>> - make dwc2 suspend/resume sourcecode work >>>> >>>> drivers/usb/dwc2/hcd.c | 88 +++++++++++++++++++++++++++++++++++++++++++------- >>>> 1 file changed, 77 insertions(+), 11 deletions(-) >>> I would certainly appreciate confirmation, but my inclination is to >>> NAK this change due to the fact that it regresses functionality. I >>> haven't done any serious review of it, but I've been testing it and it >>> appears to break hotplug. >>> >>> Said another way, I did this: >>> >>> 1. Without this patch, I booted with a USB stick in. It was detected. >>> I unplugged it, waited 5 seconds, and then plugged it back in. The >>> USB stick was redetcted. >>> >>> 2. With this patch, I did the same thing. The USB not redected after >>> plugging it back in. >> With this patch, the dwc2 hcd/root hub will be auto suspend after device >> on port is disconnected, and it can't detect the device connect any more, >> I think that's the problem. >> >> I will figure out how to make dwc2 detect the device connect after auto >> suspend, >> or disable the auto suspend feature for the dwc2 hcd. > Kever, > > This patch has made it into Linus' kernel as commit 0cf884e819e0, and > it breaks disconnect/connect on at least the Altera SOCFPGA platform. > I haven't been able to test it on any other platforms. > > You need to submit a patch to either fix this, or to only enable this > feature for the Rock-chip platform. Otherwise the patch has to be > reverted. >
