Tool/software: TI-RTOS
Hi,
I'm having an issue where my tasks are deadlocking inside i2c_close.
I currently have TI-RTOS v2.21.00.06.
I have two tasks that alternately try to talk to devices on the same I2C bus. In each task, I try to open and Task_sleep if open fails before retrying. Once the task is finished talking, it calls i2c_close on the handle it received from i2c_open.
What appears to be happening is that, when the second task calls i2c_open, handle->object->hPin is overwritten with the NULL result of PIN_open [*1] since the pin is in use. This causes the first task to deadlock in i2c_close since the pin handle is now NULL, and PIN_close apparently deadlocks when passed a null handle since it doesn't check for NULL [*2].
*1: I2CCC26XX.c:1030:
object->hPin = PIN_open(&object->pinState, i2cPinTable);
if (!object->hPin) {
return I2C_STATUS_ERROR;
}
*2: PINCC26XX.c:448:
// No need for sequencing accesses to PIN_close()
// For each pin in port bitmask
while (handle->bmPort) {
// Find lowest index pin
i = PIN_ctz(handle->bmPort);
// Deallocate pin
PIN_remove(handle, i);
}
It seems to me that using a temporary variable at I2CCC26XX.c:1030 instead of writing directly into the (potentially already open) i2c object would solve this.
Alternatively, check if the pin handle is non-null and return error if so, without overwriting a valid handle with the NULL result of a failed PIN_open.
Furthermore, PIN_close should check for null pointer and respond appropriately.
I haven't tried any of these solutions since CCS apparently won't let me edit the files in question. They were marked read only, and changing their permissions to read-write and applying appropriate edits seems to have no effect except for making the debugger confused. I tried altering my build config as per 
but this also had no apparent effect. How can I make CCS try my altered files?
In the meantime I can use a semaphore to work around this bug..
// No need for sequencing accesses to PIN_close()
// For each pin in port bitmask
while (handle->bmPort) {
// Find lowest index pin
i = PIN_ctz(handle->bmPort);
// Deallocate pin
PIN_remove(handle, i);
}
