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author | Razvan Stefanescu <razvan.stefanescu@microchip.com> | 2019-03-19 15:20:35 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-05 22:29:04 +0200 |
commit | 0668f0d6874088e7fca49c60703e1aa732616d4e (patch) | |
tree | 69987eef90ec18e93acbf6bb8c4a9ca456db9b37 /drivers/tty/synclink_gt.c | |
parent | ab18aa0d0c6d07438a098b3d5d285ec4cf4869b8 (diff) |
tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped
commit 69646d7a3689fbe1a65ae90397d22ac3f1b8d40f 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@microchip.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/synclink_gt.c')
0 files changed, 0 insertions, 0 deletions