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Fix no_console_suspend for PNP serial consoles

PATCH New Peter Hurley 1 participant 3 messages Jan 22, 2015

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TTY layer and serial drivers Pnp support
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Peter Hurley

author
#0 lore raw

v2 cover Fix no_console_suspend for PNP serial consoles

Hi Greg and Rafael,

This v2 of the earlier series submitted back in Nov addresses Rafael's comments, specifically:

* Adds PNP_CONSOLE flag, which disables the pnp protocol's suspend() and disable() methods.

This greatly simplifies the PNP serial driver patch since the existing pnp device capabilities does not need to be saved and restored now.

Note that it was necessary to continue to use macros, since struct pnp_protocol is anonymous.

Regards,

Peter Hurley (2):
PNP: Allow console to override ACPI device sleep
serial: 8250_pnp: Enable PNP_CONSOLE for console ports

 drivers/pnp/driver.c               |  2 +-
 drivers/tty/serial/8250/8250_pnp.c |  8 +++++++-
 include/linux/pnp.h                | 12 ++++++++++--
 3 files changed, 18 insertions(+), 4 deletions(-)
Signature · 1 line
2.2.2
author
#1 lore raw

PATCH v2 1/2 PNP: Allow console to override ACPI device sleep

If the serial console is an ACPI PNP device, the PNP bus always powers down the device at system suspend, even though the no_console_suspend command line parameter is specified (eg., when debugging suspend/resume).

Add PNP_CONSOLE capability, which when set, prevents calling both the ->disable() and ->suspend() PNP protocol methods if console suspend is disabled.

Signed-off-by Peter Hurley <[email protected]>
---
 drivers/pnp/driver.c |  2 +-
 include/linux/pnp.h  | 12 ++++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)
drivers/pnp/driver.c +1 -1
index f748cc8..4e57d33 100644
@@ -182,7 +182,7 @@ static int __pnp_bus_suspend(struct device *dev, pm_message_t state)
 			return error;
 	}
 
-	if (pnp_dev->protocol->suspend)
+	if (pnp_can_suspend(pnp_dev))
 		pnp_dev->protocol->suspend(pnp_dev, state);
 	return 0;
 }
include/linux/pnp.h +10 -2
index 195aafc..6512e9c 100644
@@ -12,6 +12,7 @@
 #include <linux/list.h>
 #include <linux/errno.h>
 #include <linux/mod_devicetable.h>
+#include <linux/console.h>
 
 #define PNP_NAME_LEN		50
 

@@ -309,15 +310,22 @@ struct pnp_fixup {
 #define PNP_DISABLE		0x0004
 #define PNP_CONFIGURABLE	0x0008
 #define PNP_REMOVABLE		0x0010
+#define PNP_CONSOLE		0x0020
 
 #define pnp_can_read(dev)	(((dev)->protocol->get) && \
 				 ((dev)->capabilities & PNP_READ))
 #define pnp_can_write(dev)	(((dev)->protocol->set) && \
 				 ((dev)->capabilities & PNP_WRITE))
-#define pnp_can_disable(dev)	(((dev)->protocol->disable) && \
-				 ((dev)->capabilities & PNP_DISABLE))
+#define pnp_can_disable(dev)	(((dev)->protocol->disable) &&		  \
+				 ((dev)->capabilities & PNP_DISABLE) &&	  \
+				 (!((dev)->capabilities & PNP_CONSOLE) || \
+				  console_suspend_enabled))
 #define pnp_can_configure(dev)	((!(dev)->active) && \
 				 ((dev)->capabilities & PNP_CONFIGURABLE))
+#define pnp_can_suspend(dev)	(((dev)->protocol->suspend) &&		  \
+				 (!((dev)->capabilities & PNP_CONSOLE) || \
+				  console_suspend_enabled))
+
 
 #ifdef CONFIG_ISAPNP
 extern struct pnp_protocol isapnp_protocol;
Signature · 1 line
2.2.2
author
#2 lore raw

PATCH v2 2/2 serial: 8250_pnp: Enable PNP_CONSOLE for console ports

In reply to Peter Hurley

When the kernel command line parameter, no_console_suspend, is used, the console should continue to output console messages during and after system suspend. For a serial console, the serial core ensures that the device is not shutdown when no_console_suspend is specified. However, the default operation of the pnp bus will disable and suspend the device and no further output occurs.

When registering the 8250 port, if the serial device is a console set the PNP_CONSOLE capability, which prevents device power-off if consoles are not suspending.

Signed-off-by Peter Hurley <[email protected]>
---
 drivers/tty/serial/8250/8250_pnp.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
drivers/tty/serial/8250/8250_pnp.c +7 -1
index 682a2fb..50a09cd 100644
@@ -426,7 +426,7 @@ static int serial_pnp_guess_board(struct pnp_dev *dev)
 static int
 serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 {
-	struct uart_8250_port uart;
+	struct uart_8250_port uart, *port;
 	int ret, line, flags = dev_id->driver_data;
 
 	if (flags & UNKNOWN_DEV) {

@@ -471,6 +471,10 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 	if (line < 0 || (flags & CIR_PORT))
 		return -ENODEV;
 
+	port = serial8250_get_port(line);
+	if (uart_console(&port->port))
+		dev->capabilities |= PNP_CONSOLE;
+
 	pnp_set_drvdata(dev, (void *)((long)line + 1));
 	return 0;
 }

@@ -478,6 +482,8 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 static void serial_pnp_remove(struct pnp_dev *dev)
 {
 	long line = (long)pnp_get_drvdata(dev);
+
+	dev->capabilities &= ~PNP_CONSOLE;
 	if (line)
 		serial8250_unregister_port(line - 1);
 }
Signature · 1 line
2.2.2