On Tue, Aug 14, 2018 at 2:02 PM, Oliver Neukum <oneukum@xxxxxxxx> wrote: > On Di, 2018-08-14 at 12:17 +0530, Muni Sekhar wrote: >> On Mon, Aug 13, 2018 at 7:52 PM, Muni Sekhar <munisekharrms@xxxxxxxxx> wrote: >> > On Mon, Aug 13, 2018 at 6:57 PM, Oliver Neukum <oneukum@xxxxxxxx> wrote: >> > > On Mo, 2018-08-13 at 18:44 +0530, Muni Sekhar wrote: >> > > > [ Please keep me in CC as I'm not subscribed to the list] >> > > > >> > > > Hello All, >> > > > >> > > > I’ve a FTDI serial device and it is not recognized if I connect >> > > > directly to computer. However if I connect via an external USB hub >> > > > it’s fine and I can see the FTDI serial device. What could be the >> > > > issue and how to resolve this? >> >> If I connect the FTDI device directly to computer I don't see any >> dmesg log, but after enabling the dynamic debugging for usbcore and >> hcd's driver then I see kernel log flooded with the below mentioned >> logs. Is it a bug in the hcd's driver? The same device works fine if I >> connect via an external USB hub. > > Hi, > > you are looking at an issue with the HC driver. Unfortunately you have > castrated the logs to an extent that prevents me from telling which > HC you are using. However, in any case, you need to find out and > contact its driver's maintainer. Is there any way to know which HC I’m is using? I checked the /sys/kernel/debug/usb/devices file and I see three HC’s. T: Bus=03 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=5000 MxCh= 1 B: Alloc= 0/800 us ( 0%), #Int= 0, #Iso= 0 D: Ver= 3.00 Cls=09(hub ) Sub=00 Prot=03 MxPS= 9 #Cfgs= 1 P: Vendor=1d6b ProdID=0003 Rev= 4.04 S: Manufacturer=Linux 4.4.0-28-generic xhci-hcd S: Product=xHCI Host Controller S: SerialNumber=0000:00:14.0 C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub E: Ad=81(I) Atr=03(Int.) MxPS= 4 Ivl=256ms T: Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 6 B: Alloc= 0/800 us ( 0%), #Int= 0, #Iso= 0 D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=01 MxPS=64 #Cfgs= 1 P: Vendor=1d6b ProdID=0002 Rev= 4.04 S: Manufacturer=Linux 4.4.0-28-generic xhci-hcd S: Product=xHCI Host Controller S: SerialNumber=0000:00:14.0 C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub E: Ad=81(I) Atr=03(Int.) MxPS= 4 Ivl=256ms T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 8 B: Alloc= 0/800 us ( 0%), #Int= 0, #Iso= 0 D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=1d6b ProdID=0002 Rev= 4.04 S: Manufacturer=Linux 4.4.0-28-generic ehci_hcd S: Product=EHCI Host Controller S: SerialNumber=0000:00:1d.0 C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mA I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub E: Ad=81(I) Atr=03(Int.) MxPS= 4 Ivl=256ms > > HTH > Oliver > -- Thanks, Sekhar
