mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
serial: mpc52xx: add delay after resetting transmitter to fix broken chars
This fixes receiving broken characters on the console from an MPC5125 system when systemd comes up which repeatedly opens and shuts down the console device. Trial and error with the needed interval showed that 500 us are good enough most of the time when using 38400 Bd, so I think 1 ms is a good compromise between fixing the issue and not penalize faster setups too much. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
0b1dd999b6
commit
e4b4e3176f
1 changed files with 7 additions and 0 deletions
|
@ -1135,6 +1135,13 @@ mpc52xx_uart_startup(struct uart_port *port)
|
|||
psc_ops->command(port, MPC52xx_PSC_RST_RX);
|
||||
psc_ops->command(port, MPC52xx_PSC_RST_TX);
|
||||
|
||||
/*
|
||||
* According to Freescale's support the RST_TX command can produce a
|
||||
* spike on the TX pin. So they recommend to delay "for one character".
|
||||
* One millisecond should be enough for everyone.
|
||||
*/
|
||||
msleep(1);
|
||||
|
||||
psc_ops->set_sicr(port, 0); /* UART mode DCD ignored */
|
||||
|
||||
psc_ops->fifo_init(port);
|
||||
|
|
Loading…
Reference in a new issue