x86: Do not write to VGA memory space if CONFIG_VGA_CONSOLE is undefined
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From: Pekka Enberg on 31 Mar 2010 11:40 On Wed, Mar 31, 2010 at 4:41 PM, Guenter Roeck <guenter.roeck(a)ericsson.com> wrote: > Current early_printk code writes into VGA memory space even > if CONFIG_VGA_CONSOLE is undefined. This can cause problems > if there is no VGA device in the system, especially if the memory > is used by another device. > > Fix problem by redirecting output to early_serial_console > if CONFIG_VGA_CONSOLE is undefined. > > Signed-off-by: Guenter Roeck <guenter.roeck(a)ericsson.com> Reviewed-by: Pekka Enberg <penberg(a)cs.helsinki.fi> > --- > Sorry if you have seen this before. I seem to have trouble with our mailer. > > �arch/x86/kernel/early_printk.c | � 12 ++++++++++-- > �1 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c > index b9c830c..1942039 100644 > --- a/arch/x86/kernel/early_printk.c > +++ b/arch/x86/kernel/early_printk.c > @@ -160,8 +160,16 @@ static struct console early_serial_console = { > � � � �.index = � � � �-1, > �}; > > +#ifdef CONFIG_VGA_CONSOLE > +#define EARLY_CONSOLE �early_vga_console > +static const int have_vga_console = 1; > +#else > +#define EARLY_CONSOLE �early_serial_console > +static const int have_vga_console; > +#endif > + > �/* Direct interface for emergencies */ > -static struct console *early_console = &early_vga_console; > +static struct console *early_console = &EARLY_CONSOLE; > �static int __initdata early_console_initialized; > > �asmlinkage void early_printk(const char *fmt, ...) > @@ -216,7 +224,7 @@ static int __init setup_early_printk(char *buf) > � � � � � � � � � � � �early_serial_init(buf + 4); > � � � � � � � � � � � �early_console_register(&early_serial_console, keep); > � � � � � � � �} > - � � � � � � � if (!strncmp(buf, "vga", 3) && > + � � � � � � � if (have_vga_console && !strncmp(buf, "vga", 3) && > � � � � � � � � � �boot_params.screen_info.orig_video_isVGA == 1) { > � � � � � � � � � � � �max_xpos = boot_params.screen_info.orig_video_cols; > � � � � � � � � � � � �max_ypos = boot_params.screen_info.orig_video_lines; > -- > 1.7.0.87.g0901d > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo(a)vger.kernel.org > More majordomo info at �http://vger.kernel.org/majordomo-info.html > Please read the FAQ at �http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |