On Fri, 2007-09-03 at 13:19 -0800, Pavel Machek wrote: > Hi! > > > > > -void set_console(int nr) > > +extern char vt_dont_switch; > > + > > What does this variable do and why do we want to use it here? > It's needed in set_console(). Console switch will fail if this is true.
> 'if (' > > > + (vc->vt_mode.mode != VT_PROCESS && vc->vc_mode == > KD_GRAPHICS)) { > > + > > + return -EINVAL; > > + } > > + > > I assume you want ...mode == VT_AUTO here? > > And big comment explaining why we want this behaviour? > > And another big comment explaining why this will not break existing > set_console() users? > See updated comment in attached patch. > > - set_console(SUSPEND_CONSOLE); > > + if (set_console(SUSPEND_CONSOLE)) { > > + /* Unable to change to the new console */ > > That's not what the comment should say. > > It should explain why it is okay to proceed when we can't change to > text console. > See updated comment in attached patch. It's really up to the caller to decide what to do if we can't switch the console - currently all callers ignore the return code so I assume that it's okay to proceed anyway. -- Andrew Signed-off-by: Andrew Johnson <[EMAIL PROTECTED]> --- diff -rup linux-2.6.20.1/drivers/char/vt.c linux/drivers/char/vt.c --- linux-2.6.20.1/drivers/char/vt.c 2007-02-19 22:34:32.000000000 -0800 +++ linux/drivers/char/vt.c 2007-03-09 15:48:29.000000000 -0800 @@ -2188,10 +2188,30 @@ static void console_callback(struct work release_console_sem(); } -void set_console(int nr) +extern char vt_dont_switch; + +int set_console(int nr) { + struct vc_data *vc = vc_cons[fg_console].d; + + if(!vc_cons_allocated(nr) || vt_dont_switch || + (vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) { + + /* + * Console switch will fail in console_callback() or + * change_console() so there is no point scheduling + * the callback + * + * Existing set_console() users don't check the return + * value so this shouldn't break anything + */ + return -EINVAL; + } + want_console = nr; schedule_console_callback(); + + return 0; } struct tty_driver *console_driver; diff -rup linux-2.6.20.1/drivers/char/vt_ioctl.c linux/drivers/char/vt_ioctl.c --- linux-2.6.20.1/drivers/char/vt_ioctl.c 2007-02-19 22:34:32.000000000 -0800 +++ linux/drivers/char/vt_ioctl.c 2007-03-08 14:15:41.000000000 -0800 @@ -34,7 +34,7 @@ #include <linux/kbd_diacr.h> #include <linux/selection.h> -static char vt_dont_switch; +char vt_dont_switch; extern struct tty_driver *console_driver; #define VT_IS_IN_USE(i) (console_driver->ttys[i] && console_driver->ttys[i]->count) diff -rup linux-2.6.20.1/include/linux/kbd_kern.h linux/include/linux/kbd_kern.h --- linux-2.6.20.1/include/linux/kbd_kern.h 2007-02-19 22:34:32.000000000 -0800 +++ linux/include/linux/kbd_kern.h 2007-03-08 14:15:41.000000000 -0800 @@ -75,7 +75,7 @@ extern int do_poke_blanked_console; extern void (*kbd_ledfunc)(unsigned int led); -extern void set_console(int nr); +extern int set_console(int nr); extern void schedule_console_callback(void); static inline void set_leds(void) diff -rup linux-2.6.20.1/kernel/power/console.c linux/kernel/power/console.c --- linux-2.6.20.1/kernel/power/console.c 2007-02-19 22:34:32.000000000 -0800 +++ linux/kernel/power/console.c 2007-03-09 15:52:32.000000000 -0800 @@ -27,7 +27,15 @@ int pm_prepare_console(void) return 1; } - set_console(SUSPEND_CONSOLE); + if (set_console(SUSPEND_CONSOLE)) { + /* + * We're unable to switch to the SUSPEND_CONSOLE. + * Let the calling function know so it can decide + * what to do. + */ + release_console_sem(); + return 1; + } release_console_sem(); if (vt_waitactive(SUSPEND_CONSOLE)) { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/