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PHS8/PHS8-P module is giving "Data Toggle" messages in linux environement | Thales IoT Developer Community

June 9, 2014 - 4:51pm, 2451 views

Hi, We have developed a 3G GSM board using PHS8 and PHS8-P modules. 3G board is connecting with our ARM based host board using USB. Linux OS is running on host board. PHS8/PHS8-P module is configured in multiplexed mode and ttyUSB0, ttyUSB1, ttyUSB2, ttyUSB3 and ttyUSB4 devices are created in /dev directory. We are using ttyUSB1 to get GPS data. ttyUSB2 to execute AT commands. ttyUSB3 as a GSM interface to create ppp interface. The problem is, when we try to communicate to these devices, the linux kernel USB driver is giving messages like below. user.debug kernel: musb-hdrc musb-hdrc.1: Data toggle same as previous (=0) on ep2 user.debug kernel: musb-hdrc musb-hdrc.1: Data toggle same as previous (=0) on ep3 These messages are showing the USB signal integrity related issues. We have tested the board USB interface using USB mass storage device by transferring huge data. In this test we are not getting any "Data toggling" messages. The second problem is 3G module is disappearing for some milliseconds and gets connected. Is this happening because of over heating issues? Any one here can please help me to fix these problems? Thanks, Chirag Panara