QNX RTOS v4 Knowledge Base
QNX RTOS v4 Knowledge Base
| Title |
Data corruption with the USB DDK. |
| Ref. No. |
QNX.000010320 |
| Category(ies) |
USB, Development |
| Issue |
We are getting data corruption in data written to our QNX4 USB device. The write function (called by server()) in our driver reports the number of bytes we expect (23114) in a message (write from application layer). However, data dumps in the application and in the driver show that only 1016 bytes are being copied properly. Is this the correct behaviour? |
| Solution |
Yes, this is correct behavior. The iomgr lib only has a 1024 byte receive buffer. If your app is writing more than this amount it will need to read the rest of the data. The printer class driver that comes with the USB DDK, shows how to obtain the remaining data. |
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