On 26 March 2013 15:27, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 26 Mar 2013, David Linares wrote: > >> >> While enabling usbmon, I noticed something that can be related. >> >> There is a config: "Maximum VBUS Power usage" which is currently set to >> >> 300mA in my case. >> > >> > That option (USB_GADGET_VBUS_DRAW) applies only to gadgets. That is, >> > it's meant for the part of the USB stack used in peripherals, not in >> > hosts. >> > >> >> Ok, so I guess these are the 300mA which are currently reported by the HID >> keyboard emulation for example, as I do have this gadget. > > That's right. > >> >> But here is the USB dongle I am using: >> >> >> >> lsusb -v >> >> ... >> >> idVendor 0x148f Ralink Technology, Corp. >> >> idProduct 0x5370 RT5370 Wireless Adapter >> >> .. >> >> MaxPower 450mA >> >> >> >> I guess setting 450mA will sort out my issue number 4 and avoid the >> >> "usb 1-1.1: rejected 1 configuration due to insufficient available bus power" >> >> right? >> > >> > No, it won't have any effect at all. What might help would be to plug >> > the wireless adapter into a powered hub instead of directly into your >> > computer. >> > >> >> The device I am working on is an embedded device, therefore the wireless >> adapter has to be connected to the internal hub. This hub and the whole device >> are powered via an usb cable. > > Oh. Then maybe the USB cable doesn't provide enough power to run both > the embedded device and the wireless adapter. > >> I have posted a full "lsub -v" that I ran on the device when everything works, >> just in case someone spots something very obvious: >> http://pastebin.com/HypTRS9J > > The lsusb output says that the Ralink wireless adapter will use up to > 450 mA, leaving only 50 mA available for the rest of your device. Do > you think that is enough? > There are 2 ports, so does the hub provide 500mA per port or in total? If that's 500mA for each port, that's fine. I have done some progress on my side. I have noticed that in a failing case, the 2-port hub is actually detected as a "standalone hub" but when it works fine, it is detected as a "compound device". Also printed the "hubstatus" that I get from here http://lxr.free-electrons.com/source/drivers/usb/core/hub.c#L1513 and it is really weird: - when it works, the value returned is 1, and therefore, I fall into the "Self-powered external hub" case - when it doesn't work, the value seems quite random (ex: 0xe6c0) and I fall into the 100mA limit => my Ralink wireless adapter gets a rejected config. > Alan Stern > -- 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
