* Johan Hovold <johan@xxxxxxxxxx> [211130 10:03]: > Specifically, it looks like tx can still stall indefinitely if the > autosuspend timer fires. This can happen at low baud rates and also when > using flow control. Yeah the TX part is still problematic. Note that this is purely because of current Linux serial layers implementation, and not because of any hardware reasons. Even after this series we still rely on serial8250_rpm_get_tx() and serial8250_rpm_put_tx() to decipher if we can idle the port.. If anybody has good ideas where we can add the serial core TX related paired runtime PM calls please let me know :) For TX DMA, we should not do runtime PM put until at the DMA callback function when completed. Regards, Tony
