Messages in this thread Patch in this message | | | From | Joerg Roedel <> | Subject | [PATCH] serial: 8250: Do XR17V35X specific wakeup in serial8250_do_startup | Date | Fri, 19 Jun 2015 17:12:17 +0200 |
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From: Joerg Roedel <jroedel@suse.de>
While debugging why my 8-port XR17V35X card does not work with the in-kernel serial driver, I found that some chip specific wakeup code is necessary to get it working.
Specificly the EFR_ECB bit needs to be set in the chip-specific UART_XR_EFR register, so that writing to a couple of other configuration bits is enabled.
Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Michael Welling <mwelling@ieee.org> Cc: Joe Schultz <jschultz@xes-inc.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> --- drivers/tty/serial/8250/8250_core.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 4506e40..de34db3 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -2176,6 +2176,18 @@ int serial8250_do_startup(struct uart_port *port) */ enable_rsa(up); #endif + + /* + * Do this right before clearing the FIFOs to prevent + * interrupt storm. + */ + if (port->type == PORT_XR17V35X) { + /* Wake up and initialize UART */ + serial_port_out(port, UART_XR_EFR, UART_EFR_ECB); + serial_port_out(port, UART_IER, 0); + serial_port_out(port, UART_LCR, 0); + } + /* * Clear the FIFO buffers and disable them. * (they will be reenabled in set_termios()) -- 1.8.4.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/
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