[PATCH 4/4] serial: 8250_pnp: Override pnp suspend for no_console_suspend

From: Peter Hurley
Date: Wed Nov 05 2014 - 13:41:35 EST


Prevent PNP bus from powering down the serial console device
when suspending if the no_console_suspend command line option is set.

Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_pnp.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index 50b7c89..f603581 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -487,7 +487,7 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)

if (uart_console(&port8250->port) && !console_suspend_enabled) {
info->override_disable = !!(dev->capabilities & PNP_DISABLE);
- dev->capabilities &= ~PNP_DISABLE;
+ dev->capabilities &= ~(PNP_DISABLE | PNP_SUSPEND);
}

pnp_set_drvdata(dev, info);
@@ -502,6 +502,7 @@ static void serial_pnp_remove(struct pnp_dev *dev)
serial8250_unregister_port(info->line);
if (info->override_disable)
dev->capabilities |= PNP_DISABLE;
+ dev->capabilities |= PNP_SUSPEND;
}
}

@@ -519,10 +520,25 @@ static int serial_pnp_suspend(struct pnp_dev *dev, pm_message_t state)
static int serial_pnp_resume(struct pnp_dev *dev)
{
struct serial_pnp_info *info = pnp_get_drvdata(dev);
+ unsigned int ier, mcr, lcr, dll, dlm;
+ struct uart_8250_port *port8250;

if (!info)
return -ENODEV;
+
+ port8250 = serial8250_get_port(info->line);
+ ier = serial_port_in(&port8250->port, UART_IER);
+ mcr = serial_port_in(&port8250->port, UART_MCR);
+ lcr = serial_port_in(&port8250->port, UART_LCR);
+ serial_port_out(&port8250->port, UART_LCR, lcr | UART_LCR_DLAB);
+ dll = serial_port_in(&port8250->port, UART_DLL);
+ dlm = serial_port_in(&port8250->port, UART_DLM);
+ serial_port_out(&port8250->port, UART_LCR, lcr & ~UART_LCR_DLAB);
+
serial8250_resume_port(info->line);
+
+ dev_info(&dev->dev, "IER:%02x MCR:%02x LCR:%02x DL:%02x%02x\n",
+ ier, mcr, lcr, dlm, dll);
return 0;
}
#else
--
2.1.3

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