From mboxrd@z Thu Jan 1 00:00:00 1970 From: gregory.clement@free-electrons.com (Gregory CLEMENT) Date: Tue, 04 Aug 2015 16:23:02 +0200 Subject: MUSB dual-role on AM335x behaving weirdly In-Reply-To: <55C0B954.3020106@free-electrons.com> References: <20150514190429.GT24269@saruman.tx.rr.com> <20150514192125.GU24269@saruman.tx.rr.com> <20150514192946.GV24269@saruman.tx.rr.com> <20150514212653.GC3338@piout.net> <20150526145118.GD26599@saruman.tx.rr.com> <20150527094205.GO3199@piout.net> <5594E56B.3040200@free-electrons.com> <55C0B954.3020106@free-electrons.com> Message-ID: <55C0CAC6.3020603@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi again, On 04/08/2015 15:08, Gregory CLEMENT wrote: > Hi Bin, > > On 02/07/2015 19:05, Bin Liu wrote: >> Hi, >> >> On Thu, Jul 2, 2015 at 2:16 AM, Gregory CLEMENT >> wrote: >>> Hi Felipe, >>> >>> On 27/05/2015 11:42, Alexandre Belloni wrote: >>>> Hi, >>>> >>>> On 26/05/2015 at 09:51:18 -0500, Felipe Balbi wrote : >>>>> On Thu, May 14, 2015 at 04:36:33PM -0500, Bin Liu wrote: >>>>>> Alexandre, >>>>>> >>>>>> On Thu, May 14, 2015 at 4:26 PM, Alexandre Belloni >>>>>> wrote: >>>>>>> On 14/05/2015 at 16:16:12 -0500, Bin Liu wrote : >>>>>>>> I think I found the root cause of the problem: board design issue - I >>>>>>>> bet the custom board has too much cap on VBUS line. It should be < >>>>>>>> 10uF. >>>>>>>> >>>>>>> >>>>>>> We have a custom board that exhibits the issue but it only has a 100nF >>>>>>> cap on VBUS. >>>>>> >>>>>> Have you measured the VBUS discharging? Is there any way to share your >>>>>> schematics? >>>>> >>>>> Alexandre, any further comments ? >>>>> >>>> >>>> Yeah, I have just got more info. >>>> >>>> This is the relevant part of the schematic: >>>> http://free-electrons.com/~alexandre/usb.png >>>> >>>> The total VBUS capacitance is 200nF and the USB0 pins are connected >>>> directly to the AM3358 pins. U1 is actually not fitted. >>>> >>>> We didn't measure VBUS discharging but we observe the OTG pin sensing >>>> stops when plugging an OTG cable without any device. >>> >>> Do you have any news about this topic? >>> >>> >>> Is there something else that we can do to help solving this issue? >> >> In the case of CONFIG_USB_MUSB_DUAL_ROLE=y and dr_mode=otg, how is the >> gadget driver configured? It has to be a module not built-in. > > Indeed when I configured CONFIG_USB_MUSB_HDRC=m and CONFIG_USB_MUSB_DSPS=m > it worked seamless. > Actually it didn't worked. And now sometimes I even received continuously the following message: musb_bus_suspend 2484: trying to suspend as a_wait_vfall while active Gregory -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com