atyfb: fix HP OmniBook 500 reboot hang

Apparently HP OmniBook 500's BIOS doesn't like the way atyfb reprograms
the hardware. The BIOS will simply hang after a reboot. Fix the problem
by restoring the hardware to it's original state on reboot.

Signed-off-by: Ville Syrjala <syrjala@sci.fi>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 82 insertions, 9 deletions

diff --git a/drivers/video/aty/atyfb.h b/drivers/video/aty/atyfb.h
index 7691e73823d3..0369653b5d88 100644
--- a/drivers/video/aty/atyfb.h
+++ b/drivers/video/aty/atyfb.h
@@ -187,6 +187,8 @@ struct atyfb_par {
         int mtrr_reg;
 #endif
         u32 mem_cntl;
+        struct crtc saved_crtc;
+        union aty_pll saved_pll;
 };
 
     /*
diff --git a/drivers/video/aty/atyfb_base.c b/drivers/video/aty/atyfb_base.c
index 1207c208a30b..06782906daf5 100644
--- a/drivers/video/aty/atyfb_base.c
+++ b/drivers/video/aty/atyfb_base.c
@@ -66,6 +66,8 @@
 #include <linux/spinlock.h>
 #include <linux/wait.h>
 #include <linux/backlight.h>
+#include <linux/reboot.h>
+#include <linux/dmi.h>
 
 #include <asm/io.h>
 #include <linux/uaccess.h>
@@ -249,8 +251,6 @@ static int aty_init(struct fb_info *info);
 static int store_video_par(char *videopar, unsigned char m64_num);
 #endif
 
-static struct crtc saved_crtc;
-static union aty_pll saved_pll;
 static void aty_get_crtc(const struct atyfb_par *par, struct crtc *crtc);
 
 static void aty_set_crtc(const struct atyfb_par *par, const struct crtc *crtc);
@@ -261,6 +261,8 @@ static void set_off_pitch(struct atyfb_par *par, const struct fb_info *info);
 static int read_aty_sense(const struct atyfb_par *par);
 #endif
 
+static DEFINE_MUTEX(reboot_lock);
+static struct fb_info *reboot_info;
 
     /*
      *  Interface used by the world
@@ -2390,9 +2392,9 @@ static int __devinit aty_init(struct fb_info *info)
 #endif /* CONFIG_FB_ATY_CT */
 
         /* save previous video mode */
-        aty_get_crtc(par, &saved_crtc);
+        aty_get_crtc(par, &par->saved_crtc);
         if(par->pll_ops->get_pll)
-                par->pll_ops->get_pll(info, &saved_pll);
+                par->pll_ops->get_pll(info, &par->saved_pll);
 
         par->mem_cntl = aty_ld_le32(MEM_CNTL, par);
         gtb_memsize = M64_HAS(GTB_DSP);
@@ -2667,8 +2669,8 @@ static int __devinit aty_init(struct fb_info *info)
 
 aty_init_exit:
         /* restore video mode */
-        aty_set_crtc(par, &saved_crtc);
-        par->pll_ops->set_pll(info, &saved_pll);
+        aty_set_crtc(par, &par->saved_crtc);
+        par->pll_ops->set_pll(info, &par->saved_pll);
 
 #ifdef CONFIG_MTRR
         if (par->mtrr_reg >= 0) {
@@ -3502,6 +3504,11 @@ static int __devinit atyfb_pci_probe(struct pci_dev *pdev, const struct pci_devi
         par->mmap_map[1].prot_flag = _PAGE_E;
 #endif /* __sparc__ */
 
+        mutex_lock(&reboot_lock);
+        if (!reboot_info)
+                reboot_info = info;
+        mutex_unlock(&reboot_lock);
+
         return 0;
 
 err_release_io:
@@ -3614,8 +3621,8 @@ static void __devexit atyfb_remove(struct fb_info *info)
         struct atyfb_par *par = (struct atyfb_par *) info->par;
 
         /* restore video mode */
-        aty_set_crtc(par, &saved_crtc);
-        par->pll_ops->set_pll(info, &saved_pll);
+        aty_set_crtc(par, &par->saved_crtc);
+        par->pll_ops->set_pll(info, &par->saved_pll);
 
         unregister_framebuffer(info);
 
@@ -3661,6 +3668,11 @@ static void __devexit atyfb_pci_remove(struct pci_dev *pdev)
 {
         struct fb_info *info = pci_get_drvdata(pdev);
 
+        mutex_lock(&reboot_lock);
+        if (reboot_info == info)
+                reboot_info = NULL;
+        mutex_unlock(&reboot_lock);
+
         atyfb_remove(info);
 }
 
@@ -3808,6 +3820,56 @@ static int __init atyfb_setup(char *options)
 }
 #endif  /*  MODULE  */
 
+static int atyfb_reboot_notify(struct notifier_block *nb,
+                               unsigned long code, void *unused)
+{
+        struct atyfb_par *par;
+
+        if (code != SYS_RESTART)
+                return NOTIFY_DONE;
+
+        mutex_lock(&reboot_lock);
+
+        if (!reboot_info)
+                goto out;
+
+        if (!lock_fb_info(reboot_info))
+                goto out;
+
+        par = reboot_info->par;
+
+        /*
+         * HP OmniBook 500's BIOS doesn't like the state of the
+         * hardware after atyfb has been used. Restore the hardware
+         * to the original state to allow successful reboots.
+         */
+        aty_set_crtc(par, &par->saved_crtc);
+        par->pll_ops->set_pll(reboot_info, &par->saved_pll);
+
+        unlock_fb_info(reboot_info);
+ out:
+        mutex_unlock(&reboot_lock);
+
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block atyfb_reboot_notifier = {
+        .notifier_call = atyfb_reboot_notify,
+};
+
+static const struct dmi_system_id atyfb_reboot_ids[] = {
+        {
+                .ident = "HP OmniBook 500",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "HP OmniBook PC"),
+                        DMI_MATCH(DMI_PRODUCT_VERSION, "HP OmniBook 500 FA"),
+                },
+        },
+
+        { }
+};
+
 static int __init atyfb_init(void)
 {
     int err1 = 1, err2 = 1;
@@ -3826,11 +3888,20 @@ static int __init atyfb_init(void)
     err2 = atyfb_atari_probe();
 #endif
 
-    return (err1 && err2) ? -ENODEV : 0;
+    if (err1 && err2)
+        return -ENODEV;
+
+    if (dmi_check_system(atyfb_reboot_ids))
+        register_reboot_notifier(&atyfb_reboot_notifier);
+
+    return 0;
 }
 
 static void __exit atyfb_exit(void)
 {
+        if (dmi_check_system(atyfb_reboot_ids))
+                unregister_reboot_notifier(&atyfb_reboot_notifier);
+
 #ifdef CONFIG_PCI
         pci_unregister_driver(&atyfb_driver);
 #endif