4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 31e933645742ee6719d37573a27cce0761dcf92b ]
Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support") has changed the way the autoCTS mode is handled.
According to that change, serial drivers which enable H/W autoCTS mode must set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling TX. This patch adds proper handling of UPSTAT_AUTOCTS flag.
Signed-off-by: Beomho Seo beomho.seo@samsung.com [mszyprow: rephrased commit message] Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/samsung.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index da1bd4bba8a9..2a49b6d876b8 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -1365,11 +1365,14 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, wr_regl(port, S3C2410_ULCON, ulcon); wr_regl(port, S3C2410_UBRDIV, quot);
+ port->status &= ~UPSTAT_AUTOCTS; + umcon = rd_regl(port, S3C2410_UMCON); if (termios->c_cflag & CRTSCTS) { umcon |= S3C2410_UMCOM_AFC; /* Disable RTS when RX FIFO contains 63 bytes */ umcon &= ~S3C2412_UMCON_AFC_8; + port->status = UPSTAT_AUTOCTS; } else { umcon &= ~S3C2410_UMCOM_AFC; }