Hi, On Thu, Jul 2, 2015 at 2:16 AM, Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx> 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 >>>> <alexandre.belloni@xxxxxxxxxxxxxxxxxx> 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. Regards, -Bin. > > > Thanks, > > Gregory > > > -- > Gregory Clement, Free Electrons > Kernel, drivers, real-time and embedded Linux > development, consulting, training and support. > http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
