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| author | Hongyu Xie <xiehongyu1@kylinos.cn> | 2023-05-01 10:09:09 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-13 13:32:21 +0300 |
| commit | 6d8c1fca0a6ee4915781ded60000b3cc2c076e29 (patch) | |
| tree | b6aea39bd9394fca6d4dbc1e94174be1f3380292 | |
| parent | cf9aa72d2f91defea23fe29b9e8e941bb2486d5c (diff) | |
| download | linux-6d8c1fca0a6ee4915781ded60000b3cc2c076e29.tar.xz | |
serial: pl011: set UART011_CR_RXE in pl011_set_termios after port shutdown
UART011_CR_RXE is set in pl011_startup() during normal initialization, and
cleared by pl011_disable_uart() during port shutdown.
You can use a none-console port in poll mode like kgdboc does with
tty_find_polling_driver() after a port shutdown. But pl011_startup() is not
called in tty_find_polling_driver(). So you need to set UART011_CR_RXE to
reenable receive function.
Not sure setting UART011_CR_RXE in pl011_set_termios() is a good idea
through.
Signed-off-by: Hongyu Xie <xiehongyu1@kylinos.cn>
Link: https://lore.kernel.org/r/20230501070909.1144547-1-xiehongyu1@kylinos.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index d8c2f3455eeb..c5c3f4674459 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2166,6 +2166,13 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios, * ----------^----------^----------^----------^----- */ pl011_write_lcr_h(uap, lcr_h); + + /* + * Receive was disabled by pl011_disable_uart during shutdown. + * Need to reenable receive if you need to use a tty_driver + * returns from tty_find_polling_driver() after a port shutdown. + */ + old_cr |= UART011_CR_RXE; pl011_write(old_cr, uap, REG_CR); spin_unlock_irqrestore(&port->lock, flags); |