On Wed, Apr 03, 2019 at 03:07:18PM +0000, Razvan.Stefanescu@xxxxxxxxxxxxx wrote: > > > On 03/04/2019 17:02, Greg Kroah-Hartman wrote: > > On Tue, Apr 02, 2019 at 12:52:50PM +0300, Razvan Stefanescu wrote: > >> commit 69646d7a3689 ("tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped") upstream. > >> > >> In half-duplex operation, RX should be started after TX completes. > >> > >> If DMA is used, there is a case when the DMA transfer completes but the > >> TX FIFO is not emptied, so the RX cannot be restarted just yet. > >> > >> Use a boolean variable to store this state and rearm TX interrupt mask > >> to be signaled again that the transfer finished. In interrupt transmit > >> handler this variable is used to start RX. A warning message is generated > >> if RX is activated before TX fifo is cleared. > >> > >> Fixes: b389f173aaa1 ("tty/serial: atmel: RS485 half duplex w/DMA: enable > >> RX after TX is done") > >> Signed-off-by: Razvan Stefanescu <razvan.stefanescu@xxxxxxxxxxxxx> > >> Acked-by: Richard Genoud <richard.genoud@xxxxxxxxx> > >> Cc: stable <stable@xxxxxxxxxxxxxxx> > >> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > >> --- > >> drivers/tty/serial/atmel_serial.c | 24 +++++++++++++++++++++--- > >> 1 file changed, 21 insertions(+), 3 deletions(-) > >> > > > > Happen to have a version of this for 4.4.y and 4.9.y? > > > > I've queued both of these patches up now, thanks. > > > > Thank you for picking them. I've sent the patches for 4.4.y and 4.9.y. Thanks for those, now queued up. greg k-h