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OpenNuvoton / NUC970_Linux_Kernel

Linux Kernel Source Code for NUC970 Series Microprocessor
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usb gsm modems drviers error #15

Closed junwushi closed 7 years ago

junwushi commented 7 years ago

usb1 connect UC20 modem module,and show below error info: i search the reason on internet, they are said usb clk setting error.

[ 2.690000] usb 2-2: new low-speed USB device number 2 using nuc970-ohci [ 2.880000] usb 2-2: device descriptor read/64, error -62 [ 3.170000] usb 2-2: device descriptor read/64, error -62 [ 3.460000] usb 2-2: new low-speed USB device number 3 using nuc970-ohci [ 3.650000] usb 2-2: device descriptor read/64, error -62

junwushi commented 7 years ago

please check soon

yachen commented 7 years ago

Nope, this is not a clock setting issue. From you log, the modem module was identified as a low speed device, which it is not. So it's more likely to be D+/D- signal issue. What board are you using?

Sincerely,

Yi-An Chen

junwushi commented 7 years ago

i am in my self device,the modem is usb 2.0 device not low speed device, and not give advise for pull-up resistor in dp or dp pin in the modem hardware design document

yachen commented 7 years ago

Hi,

Below is the USB layout guideline in our document.

  1. DP/DM traces should be length matched and as close as possible to the connector.
  2. Route DP/DM traces should be close together for noise rejection on the differential signals, parallel to each other and the length difference within 200-mil.
  3. If the common chock is necessary, it should be as close as to the connector.
  4. No extra components at DP/DM pair traces to maintain signal integrity.
  5. No de-coupled caps on the DP/DM.
  6. The characteristic of matching impedance 90 Ohm on the DP/DM is necessary.
  7. Stubs on high speed USB signals should be avoided, as stubs will cause signal reflections and affect signal quality. If a stub is unavoidable in the design, no stub should be greater than 200 mils.
  8. Route all traces over continuous planes (VCC or GND), with no interruptions. Avoid crossing over anti-etch if at all possible. Crossing over anti-etch (plane splits) increases inductance and radiation levels by forcing a greater loop area. Likewise, avoid changing layers with high-speed traces as much as practical. It is preferable to change layers to avoid crossing a plane split.
  9. Use the following guidelines for the VCC OR GND plane. a. Traces should not cross anti-etch, for it greatly increases the return path for those signal traces. This applies to High Speed USB signals, high-speed clock and signal traces as well as slower signal traces, which might be coupling to them. USB signaling is not purely differential in all speeds (i.e. the FS Single Ended Zero is common mode) b. Avoid routing of USB signals within 25 mils of any anti-etch to avoid coupling to the next split or radiating from the edge of the PCB.
  10. Separate signal traces into similar categories and route similar signal traces together (such as routing differential pairs together).
  11. Keep high-speed USB signals clear of the core logic set. High current transients are produced during internal state transitions and can be very difficult to filter out.
  12. Follow the 20h thumb rule by keeping traces at least 20(height above the plane) away from the edge of the plane (VCC or GND, depending on the plane the trace is over). For the suggested stack up the height above the plane are 4.5 mils. This calculates to a 90-mil spacing requirement from the edge of the plane. This helps prevent the coupling of the signal onto adjacent wires and also helps prevent free radiation of the signal from the edge of the PCB.

Sincerely,

Yi-An Chen

junwushi commented 7 years ago

sorry maybe hardware problem,i changed another board ,it is working.

gateway login: [ 12.330000] usb 1-2: new high-speed USB device number 4 using nuc970-ehci [ 17.710000] usb 1-2: new high-speed USB device number 5 using nuc970-ehci [ 23.090000] usb 1-2: new high-speed USB device number 6 using nuc970-ehci [ 28.670000] usb 2-2: new full-speed USB device number 2 using nuc970-ohci [ 28.880000] usb 2-2: not running at top speed; connect to a high speed hub [ 28.920000] option 2-2:1.0: GSM modem (1-port) converter detected [ 28.940000] usb 2-2: GSM modem (1-port) converter now attached to ttyUSB0 [ 28.960000] option 2-2:1.1: GSM modem (1-port) converter detected [ 28.970000] usb 2-2: GSM modem (1-port) converter now attached to ttyUSB1 [ 28.990000] option 2-2:1.2: GSM modem (1-port) converter detected [ 29.010000] usb 2-2: GSM modem (1-port) converter now attached to ttyUSB2 [ 29.020000] option 2-2:1.3: GSM modem (1-port) converter detected [ 29.020000] usb 2-2: GSM modem (1-port) converter now attached to ttyUSB3