Re: Kill unneccessary debug printk [PATCH]

[John Mock <kd6pag@qsl.net>]

    > Better yet, let's take this opportunity to do this more cleanly.  How 
    > about having something like /sys/power/vmode (or /proc/...) contain that 
    > inforemation instead?  With luck, it might even be few kernel bytes than
    > the original printk (or at least not much more).  (I know nothing about
    > either /proc or /sys, so it would take me awhile to suggest a patch).

    Well, you probably know about as much as I do. I'm afraid I'm just
    going to take the easy way out.
								    Pavel

OK, then, here's a quick fix (perhaps someone else can refine it) which 
reads back saved video mode via '/sys/power/gmode'.  Maybe someone else
who understand mechanism better than i do can come up with some cleaner
code to do the same thing (or at least find a better place to put this).
Hopefully, i've at least picked the right CONFIG variable...

				-- JM

Attachment: Patch to 2.6.0-test8-bk2
-------------------------------------------------------------------------------
--- ./kernel/power/disk.c.orig	2003-10-17 14:42:53.000000000 -0700
+++ ./kernel/power/disk.c	2003-10-25 00:02:10.000000000 -0700
@@ -326,10 +326,55 @@
 	.attrs = g,
 };
 
-
 static int __init pm_disk_init(void)
 {
 	return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
 }
 
 core_initcall(pm_disk_init);
+
+#ifdef CONFIG_VIDEO_SELECT
+/*
+ *	gmode - report graphics mode
+ *
+ * In order for software suspend to succeed, the video mode must match that
+ * supplied via the console or from the kernel command line.  This provides
+ * an orderly means of retrieving that information (rather than grep'ing
+ * 'dmesg' at an appropriate time, as was the previous means of obtaining
+ * this datum).
+ *
+ * TO DO:  Make sure framebuffer code updates 'saved_videomode' if it is
+ *	   capable of changing the video mode ('vesafb' apparently cannot).
+ */
+extern unsigned long saved_videomode;
+
+static ssize_t gmode_show(struct subsystem * subsys, char * buf)
+{
+	return sprintf(buf,"0x%lx\n",saved_videomode);
+}
+
+static ssize_t gmode_store(struct subsystem * s, const char * buf, size_t n) {
+	return -EINVAL;
+}
+
+/* Probably should use some macro which makes 'gmode' read-only, since the
+   above code didn't report an error when storing into /sys/prog/gmode */
+power_attr(gmode);
+
+static struct attribute * g2[] = {
+	&gmode_attr.attr,
+	NULL,
+};
+
+static struct attribute_group attr_group2 = {
+	.attrs = g2,
+};
+
+static int __init pm_gmode_init(void)
+{
+	return sysfs_create_group(&power_subsys.kset.kobj,&attr_group2);
+}
+
+core_initcall(pm_gmode_init);
+
+#endif /* CONFIG_VIDEO_SELECT */

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