From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Andrew Morton <akpm@osdl.org>
Cc: LKML <linux-kernel@vger.kernel.org>, Pavel Machek <pavel@suse.cz>
Subject: [PATCH -mm 2/3] pm: check console before suspending devices
Date: Sun, 19 Mar 2006 12:05:31 +0100 [thread overview]
Message-ID: <200603191205.32346.rjw@sisk.pl> (raw)
In-Reply-To: <200603191158.26275.rjw@sisk.pl>
From: "Rafael J. Wysocki" <rjw@sisk.pl>
It is unsafe to suspend devices if the hardware is controlled by X.
Add an extra check to prevent this from happening.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/base/power/suspend.c | 5 ++++-
drivers/char/vt.c | 8 ++++++++
include/linux/vt_kern.h | 5 +++++
3 files changed, 17 insertions(+), 1 deletion(-)
Index: linux-2.6.16-rc6-mm2/drivers/base/power/suspend.c
===================================================================
--- linux-2.6.16-rc6-mm2.orig/drivers/base/power/suspend.c
+++ linux-2.6.16-rc6-mm2/drivers/base/power/suspend.c
@@ -8,6 +8,7 @@
*
*/
+#include <linux/vt_kern.h>
#include <linux/device.h>
#include <linux/kallsyms.h>
#include <linux/pm.h>
@@ -65,7 +66,6 @@ int suspend_device(struct device * dev,
return error;
}
-
/**
* device_suspend - Save state and stop all devices in system.
* @state: Power state to put each device in.
@@ -85,6 +85,9 @@ int device_suspend(pm_message_t state)
{
int error = 0;
+ if (!is_console_suspend_safe())
+ return -EINVAL;
+
down(&dpm_sem);
down(&dpm_list_sem);
while (!list_empty(&dpm_active) && error == 0) {
Index: linux-2.6.16-rc6-mm2/drivers/char/vt.c
===================================================================
--- linux-2.6.16-rc6-mm2.orig/drivers/char/vt.c
+++ linux-2.6.16-rc6-mm2/drivers/char/vt.c
@@ -3234,6 +3234,14 @@ void vcs_scr_writew(struct vc_data *vc,
}
}
+/* It is unsafe to suspend devices while X has control of the
+ * hardware. Check if we are running on a kernel-controlled console.
+ */
+int is_console_suspend_safe(void)
+{
+ return vc_cons[fg_console].d->vc_mode == KD_TEXT;
+}
+
/*
* Visible symbols for modules
*/
Index: linux-2.6.16-rc6-mm2/include/linux/vt_kern.h
===================================================================
--- linux-2.6.16-rc6-mm2.orig/include/linux/vt_kern.h
+++ linux-2.6.16-rc6-mm2/include/linux/vt_kern.h
@@ -73,6 +73,11 @@ int con_copy_unimap(struct vc_data *dst_
int vt_waitactive(int vt);
void change_console(struct vc_data *new_vc);
void reset_vc(struct vc_data *vc);
+#ifdef CONFIG_VT
+int is_console_suspend_safe(void);
+#else
+static inline int is_console_suspend_safe(void) { return 1; }
+#endif
/*
* vc_screen.c shares this temporary buffer with the console write code so that
next prev parent reply other threads:[~2006-03-19 11:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200603191158.26275.rjw@sisk.pl>
2006-03-19 11:05 ` [PATCH -mm 1/3] swsusp: let userland tools switch console on suspend Rafael J. Wysocki
2006-03-19 11:05 ` Rafael J. Wysocki [this message]
2006-03-19 11:16 ` [PATCH -mm 3/3] swsusp: add s2ram ioctl to userland interface Rafael J. Wysocki
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