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| author | Mingrui Ren <jiladahe1997@gmail.com> | 2020-12-02 15:25:43 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-04 16:54:20 +0100 |
| commit | aef1b6a27970607721a618a0b990716ca8dbbf97 (patch) | |
| tree | ac97b7ba08dc9039459c8d0f9133956aa4c095a2 /drivers/tty | |
| parent | 7af77ba42467da8a4dbfe0dfd0a467227e8fbe5f (diff) | |
| download | lwn-aef1b6a27970607721a618a0b990716ca8dbbf97.tar.gz lwn-aef1b6a27970607721a618a0b990716ca8dbbf97.zip | |
tty/serial/imx: Enable TXEN bit in imx_poll_init().
As described in Documentation, poll_init() is called by kgdb to initialize
hardware which supports both poll_put_char() and poll_get_char().
It's necessary to enable TXEN bit, otherwise, it will cause hardware fault
and kernel panic when calling imx_poll_put_char().
Generally, if use /dev/ttymxc0 as kgdb console as well as system
console, ttymxc0 is initialized early by system console which does enable
TXEN bit.But when use /dev/ttymxc1 as kgbd console, ttymxc1 is only
initialized by imx_poll_init() cannot enable the TXEN bit, which will
cause kernel panic.
Signed-off-by: Mingrui Ren <jiladahe1997@gmail.com>
Link: https://lore.kernel.org/r/20201202072543.151-1-972931182@qq.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/imx.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index b50f97cb07e9..cafa88df5a85 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1861,7 +1861,7 @@ static int imx_uart_poll_init(struct uart_port *port) ucr1 |= UCR1_UARTEN; ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN); - ucr2 |= UCR2_RXEN; + ucr2 |= UCR2_RXEN | UCR2_TXEN; ucr2 &= ~UCR2_ATEN; imx_uart_writel(sport, ucr1, UCR1); |