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| author | Marek Vasut <marex@denx.de> | 2023-02-23 05:22:52 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-11 23:03:27 +0900 |
| commit | c996ca87cf68e5ffa34f1c0f3657463bf07da03a (patch) | |
| tree | db69b324b2549270f7749b1d9377dfba4417d65b /net/ethtool | |
| parent | 3c5fafc27c02ff8a3a71fa4b0db2444e6f9d94c1 (diff) | |
| download | linux-c996ca87cf68e5ffa34f1c0f3657463bf07da03a.tar.gz | |
serial: stm32: Re-assert RTS/DE GPIO in RS485 mode only if more data are transmitted
[ Upstream commit c47527cbcc3c50800f34b8c684f29721f75de246 ]
The stm32_usart_transmit_chars() may be called with empty or stopped
transmit queue, and no XON/OFF character pending. This can happen at
the end of transmission, where this last call is used to either handle
the XON/XOFF x_char, or disable TX interrupt if queue is empty or
stopped.
If that occurs, do not assert the RS485 RTS/DE GPIO anymore, as the
GPIO would remain asserted past the end of transmission and that would
block the RS485 bus after the transmission.
Only assert the RS485 RTS/DE GPIO if there is either pending XON/XOFF
x_char, or at least one character in running transmit queue.
Fixes: d7c76716169d ("serial: stm32: Use TC interrupt to deassert GPIO RTS in RS485 mode")
Signed-off-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20230223042252.95480-2-marex@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/ethtool')
0 files changed, 0 insertions, 0 deletions