imx28 cpu is blocked when acm modem is opened without read/write

[mehmet]

Hello all,

We have a critical problem with imx28. We use Telit HE910 module for GSM and GPS, it has 7 ACM interface under /dev/ directory and /dev/ttyACM0 is for GSM, /dev/ttyACM2 is for GPS. When we opened any 2 ports of /dev/ttyACMx, cpu is blocked for a few milliseconds. Because of imx28 has 16 bytes uart fifo, data loss would occur. The funny part is that there is no transfer, no read/write request on /dev/ttyACMx's, only opened any 2 of them.

So thanks.

Mehmetmet

[mehmet]

I have striven for a few weeks but there is no good result. Isn't there anyone who can help?

[MarekVasut]

There was discussion about AUART data loss in mainline Linux, but it was fixed in the end. You might want to take a look in there (or use mainline).