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Date: Fri, 12 Feb 2010 16:36:24 -0600
From: Jason Wessel <jason.wessel@...driver.com>
To: linux-kernel@...r.kernel.org
Cc: kgdb-bugreport@...ts.sourceforge.net, mingo@...e.hu,
Jason Wessel <jason.wessel@...driver.com>,
David Airlie <airlied@...ux.ie>,
Jesse Barnes <jbarnes@...tuousgeek.org>
Subject: [PATCH 3/7] kms,kdb: Force unblank a console device
The kgdboc pre exception handler must atomically save the state of the
existing VC console and activate it, if it is blanked.
Before restoring the kernel to a running state, the kgdboc post
exception handler will restore the state of the VC variables that got
changed while atomic.
CC: David Airlie <airlied@...ux.ie>
CC: Jesse Barnes <jbarnes@...tuousgeek.org>
Signed-off-by: Jason Wessel <jason.wessel@...driver.com>
---
drivers/serial/kgdboc.c | 25 ++++++++++++----
drivers/video/console/fbcon.c | 7 ++++
include/linux/kgdb.h | 8 +++++
kernel/debug/Makefile | 1 +
kernel/debug/kms_hooks.c | 62 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 96 insertions(+), 7 deletions(-)
create mode 100644 kernel/debug/kms_hooks.c
diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c
index bc1fec1..246b7c3 100644
--- a/drivers/serial/kgdboc.c
+++ b/drivers/serial/kgdboc.c
@@ -220,13 +220,19 @@ static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp)
return configure_kgdboc();
}
+static int dbg_restore_graphics;
+
static void kgdboc_pre_exp_handler(void)
{
- if (kgdboc_use_kms && dbg_kms_ops &&
- dbg_kms_ops->activate_console)
- if (dbg_kms_ops->activate_console(dbg_kms_ops))
+ if (!dbg_restore_graphics && kgdboc_use_kms && dbg_kms_ops &&
+ dbg_kms_ops->activate_console) {
+ if (dbg_kms_ops->activate_console(dbg_kms_ops)) {
printk(KERN_ERR "kgdboc: kernel mode switch error\n");
-
+ } else {
+ dbg_restore_graphics = 1;
+ dbg_pre_vt_hook();
+ }
+ }
/* Increment the module count when the debugger is active */
if (!kgdb_connected)
try_module_get(THIS_MODULE);
@@ -238,9 +244,14 @@ static void kgdboc_post_exp_handler(void)
if (!kgdb_connected)
module_put(THIS_MODULE);
if (kgdboc_use_kms && dbg_kms_ops &&
- dbg_kms_ops->restore_console)
- if (dbg_kms_ops->restore_console(dbg_kms_ops))
- printk(KERN_ERR "kgdboc: graphics restore failed\n");
+ dbg_kms_ops->restore_console) {
+ if (dbg_restore_graphics) {
+ if (dbg_kms_ops->restore_console(dbg_kms_ops))
+ printk(KERN_ERR "kgdboc: graphics restore failed\n");
+ dbg_restore_graphics = 0;
+ dbg_post_vt_hook();
+ }
+ }
kgdboc_clear_kbd();
}
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 3681c6a..6f2ed5a 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -75,6 +75,7 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/crc32.h> /* For counting font checksums */
+#include <linux/kgdb.h>
#include <asm/fb.h>
#include <asm/irq.h>
#include <asm/system.h>
@@ -2318,6 +2319,12 @@ static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch)
}
}
+ if (in_dbg_master()) {
+ if (info->fbops->fb_blank)
+ info->fbops->fb_blank(blank, info);
+ return 0;
+ }
+
if (!fbcon_is_inactive(vc, info)) {
if (ops->blank_state != blank) {
ops->blank_state = blank;
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index 9cd6baa..81bb298 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -286,6 +286,14 @@ extern atomic_t kgdb_active;
#endif /* CONFIG_KGDB */
/* Common to all that include kgdb.h */
+#ifdef CONFIG_VT
+extern void dbg_pre_vt_hook(void);
+extern void dbg_post_vt_hook(void);
+#else /* ! CONFIG_VT */
+#define dbg_pre_vt_hook()
+#define dbg_post_vt_hook()
+#endif /* CONFIG_VT */
+
struct dbg_kms_ops {
int (*activate_console) (struct dbg_kms_ops *ops);
int (*restore_console) (struct dbg_kms_ops *ops);
diff --git a/kernel/debug/Makefile b/kernel/debug/Makefile
index c72de00..fe342c0 100644
--- a/kernel/debug/Makefile
+++ b/kernel/debug/Makefile
@@ -3,5 +3,6 @@
#
obj-$(CONFIG_KGDB) += debug_core.o gdbstub.o
+obj-$(CONFIG_VT) += kms_hooks.o
obj-$(CONFIG_KGDB_KDB) += kdb/
diff --git a/kernel/debug/kms_hooks.c b/kernel/debug/kms_hooks.c
new file mode 100644
index 0000000..c56b7ce
--- /dev/null
+++ b/kernel/debug/kms_hooks.c
@@ -0,0 +1,62 @@
+/*
+ * Created by: Jason Wessel <jason.wessel@...driver.com>
+ *
+ * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifdef CONFIG_VT
+#include <linux/kgdb.h>
+#include <linux/console.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+#include <linux/kdb.h>
+#include "kdb/kdb_private.h"
+
+static int dbg_orig_vc_mode;
+static int saved_fg_con;
+static int saved_last_con;
+static int saved_want_con;
+
+void dbg_pre_vt_hook(void)
+{
+ struct vc_data *vc = vc_cons[fg_console].d;
+ saved_fg_con = fg_console;
+ saved_last_con = last_console;
+ saved_want_con = want_console;
+ dbg_orig_vc_mode = vc->vc_mode;
+ vc->vc_mode = KD_TEXT;
+ console_blanked = 0;
+ vc->vc_sw->con_blank(vc, 0, 1);
+ vc->vc_sw->con_set_palette(vc, color_table);
+#ifdef CONFIG_KGDB_KDB
+ /* Set the initial LINES variable if it is not already set */
+ if (vc->vc_rows < 999) {
+ int linecount;
+ char lns[4];
+ const char *setargs[3] = {
+ "set",
+ "LINES",
+ lns,
+ };
+ if (kdbgetintenv(setargs[0], &linecount)) {
+ snprintf(lns, 4, "%i", vc->vc_rows);
+ kdb_set(2, setargs);
+ }
+ }
+#endif /* CONFIG_KGDB_KDB */
+}
+EXPORT_SYMBOL_GPL(dbg_pre_vt_hook);
+
+void dbg_post_vt_hook(void)
+{
+ fg_console = saved_fg_con;
+ last_console = saved_last_con;
+ want_console = saved_want_con;
+ vc_cons[fg_console].d->vc_mode = dbg_orig_vc_mode;
+}
+EXPORT_SYMBOL_GPL(dbg_post_vt_hook);
+#endif /* CONFIG_VT */
--
1.6.4.rc1
--
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