Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | Re: -mm: PM=y, VT=n doesn't compile | Date | Sat, 18 Mar 2006 21:28:02 +0100 |
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On Saturday 18 March 2006 20:58, Rafael J. Wysocki wrote: > On Saturday 18 March 2006 20:48, Andrew Morton wrote: > > "Rafael J. Wysocki" <rjw@sisk.pl> wrote: > > > > > > --- 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 +8,9 @@ > > > * > > > */ > > > > > > +#include <linux/vt_kern.h> > > > +#include <linux/kbd_kern.h> > > > +#include <linux/console.h> > > > #include <linux/device.h> > > > #include <linux/kallsyms.h> > > > #include <linux/pm.h> > > > @@ -65,6 +68,17 @@ int suspend_device(struct device * dev, > > > return error; > > > } > > > > > > +#ifdef CONFIG_VT > > > +static inline int is_suspend_console_safe(void) > > > +{ > > > + /* It is unsafe to suspend devices while X has control of the > > > + * hardware. Make sure we are running on a kernel-controlled console. > > > + */ > > > + return vc_cons[fg_console].d->vc_mode == KD_TEXT; > > > +} > > > > Please implement this inside the vt subsystem, not the pm subsystem. That way > > > > a) It gets to be called "console_is_in_text_mode()", or > > "vt_not_running_X()" or something, which is something someone else might > > want to know. > > > > b) People who work on vt code don't need to keep an eye on a hunk of pm > > code at the same time. > > > > c) You won't need all those includes. > > I'm working on this now. [For some obscure reason I received your reply to > Adrian only a couple of minutes ago.] > > Still I'd like to separate it from the console-related changes in > kernel/power/user.c that are needed for the userland suspend, so I'd like > to split the dropped patch in two. > > I've already sent the kernel/power/user.c changes in a separate patch, > and I'll send the drivers/base/power/suspend.c changes when I test them > (in a while).
OK, here they go.
--- 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, } } +int is_console_suspend_safe(void) +{ + /* It is unsafe to suspend devices while X has control of the + * hardware. Make sure we are running on a kernel-controlled console. + */ + 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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