MQX Software SolutionsのトピックUSB CDC HUB read is blocking in highspeed https://community.nxp.com/t5/MQX-Software-Solutions/USB-CDC-HUB-read-is-blocking-in-highspeed/m-p/714598#M17595 <HTML><HEAD></HEAD><BODY><P style="margin: 0in 0in 8pt;"><EM style="font-size: 10pt;">Hello All,</EM></P><P style="margin: 0in 0in 8pt;"><EM style="font-size: 10pt;">Good day.</EM></P><P style="margin: 0in 0in 8pt;"><EM style="font-size: 10pt;">The USB CDC read call implementation in usb_host_cdc.c (mqx stack version 4.1) ,i.e, _lwevent_wait_ticks(event,USB_DATA_READ_COMPLETE | USB_DATA_DETACH, FALSE, 0) “waits” on “event” object forever until it receives data on USB port. The USB ISR should trigger “release” of the “event” when data is available but when CDC Wi-fi dongle connected to a high speed port(through USB hub IC&nbsp; 2512) to K70 board, it is observed that the event USB_DATA_READ_COMPLETE does not occur even after an extended period of time(over 5 minutes). </EM></P><P style="margin: 0in 0in 8pt;"><EM style=": ; text-decoration: underline; font-size: 10pt;">Possible reasons:</EM></P><UL><LI><EM><EM style="font-size: 10pt;">ISR overloading?</EM></EM></LI></UL><UL><LI style="color: #000000; font-size: 10pt;"><EM><EM style="font-size: 10pt;">Data isn’t being read / minimum data needed for high speed operation is not present on the bus?</EM></EM></LI></UL><P></P><P></P><P><EM style="font-size: 10pt;">However if the same CDC Wi-fi dongle is connected to the USB full speed port, the communication proceeds perfectly. Kindly help to identify the root cause and resolve the issue.</EM> </P><P></P><P>Thanks in advance,</P><P>Jins</P></BODY></HTML> Wed, 27 Sep 2017 05:38:11 GMT jinspaul1 2017-09-27T05:38:11Z USB CDC HUB read is blocking in highspeed https://community.nxp.com/t5/MQX-Software-Solutions/USB-CDC-HUB-read-is-blocking-in-highspeed/m-p/714598#M17595 <HTML><HEAD></HEAD><BODY><P style="margin: 0in 0in 8pt;"><EM style="font-size: 10pt;">Hello All,</EM></P><P style="margin: 0in 0in 8pt;"><EM style="font-size: 10pt;">Good day.</EM></P><P style="margin: 0in 0in 8pt;"><EM style="font-size: 10pt;">The USB CDC read call implementation in usb_host_cdc.c (mqx stack version 4.1) ,i.e, _lwevent_wait_ticks(event,USB_DATA_READ_COMPLETE | USB_DATA_DETACH, FALSE, 0) “waits” on “event” object forever until it receives data on USB port. The USB ISR should trigger “release” of the “event” when data is available but when CDC Wi-fi dongle connected to a high speed port(through USB hub IC&nbsp; 2512) to K70 board, it is observed that the event USB_DATA_READ_COMPLETE does not occur even after an extended period of time(over 5 minutes). </EM></P><P style="margin: 0in 0in 8pt;"><EM style=": ; text-decoration: underline; font-size: 10pt;">Possible reasons:</EM></P><UL><LI><EM><EM style="font-size: 10pt;">ISR overloading?</EM></EM></LI></UL><UL><LI style="color: #000000; font-size: 10pt;"><EM><EM style="font-size: 10pt;">Data isn’t being read / minimum data needed for high speed operation is not present on the bus?</EM></EM></LI></UL><P></P><P></P><P><EM style="font-size: 10pt;">However if the same CDC Wi-fi dongle is connected to the USB full speed port, the communication proceeds perfectly. Kindly help to identify the root cause and resolve the issue.</EM> </P><P></P><P>Thanks in advance,</P><P>Jins</P></BODY></HTML> Wed, 27 Sep 2017 05:38:11 GMT https://community.nxp.com/t5/MQX-Software-Solutions/USB-CDC-HUB-read-is-blocking-in-highspeed/m-p/714598#M17595 jinspaul1 2017-09-27T05:38:11Z