The port drain_delay parameter is used to add a time-based delay when closing the port in order to allow the transmit FIFO to drain in cases where we don't know how to tell if the FIFO is empty. This series removes a redundant time-based delay which is no longer needed, and documents the reason for two other uses where such a delay is needed to let the transmitter shift register clear. As it turns out, this is really only needed for one of the two device types handled by the ti_usb_3410_5052 driver. Johan Johan Hovold (4): USB: serial: f81232: drop time-based drain delay USB: serial: io_ti: document reason for drain delay USB: serial: ti_usb_3410_5052: reduce drain delay to one char USB: serial: ti_usb_3410_5052: drop drain delay for 3410 drivers/usb/serial/f81232.c | 1 - drivers/usb/serial/io_ti.c | 4 ++++ drivers/usb/serial/ti_usb_3410_5052.c | 21 ++++++++++++++++++--- 3 files changed, 22 insertions(+), 4 deletions(-) -- 2.26.3