1 files changed, 37 insertions, 4 deletions

diff --git a/drivers/misc/cs5535-mfgpt.c b/drivers/misc/cs5535-mfgpt.c
index 9858f36dad8b..effd8c6b2b94 100644
--- a/drivers/misc/cs5535-mfgpt.c
+++ b/drivers/misc/cs5535-mfgpt.c
@@ -24,8 +24,11 @@
 
 static int mfgpt_reset_timers;
 module_param_named(mfgptfix, mfgpt_reset_timers, int, 0644);
-MODULE_PARM_DESC(mfgptfix, "Reset the MFGPT timers during init; "
-                "required by some broken BIOSes (ie, TinyBIOS < 0.99).");
+MODULE_PARM_DESC(mfgptfix, "Try to reset the MFGPT timers during init; "
+                "required by some broken BIOSes (ie, TinyBIOS < 0.99) or kexec "
+                "(1 = reset the MFGPT using an undocumented bit, "
+                "2 = perform a soft reset by unconfiguring all timers); "
+                "use what works best for you.");
 
 struct cs5535_mfgpt_timer {
         struct cs5535_mfgpt_chip *chip;
@@ -256,6 +259,28 @@ static void reset_all_timers(void)
 }
 
 /*
+ * This is another sledgehammer to reset all MFGPT timers.
+ * Instead of using the undocumented bit method it clears
+ * IRQ, NMI and RESET settings.
+ */
+static void soft_reset(void)
+{
+        int i;
+        struct cs5535_mfgpt_timer t;
+
+        for (i = 0; i < MFGPT_MAX_TIMERS; i++) {
+                t.nr = i;
+
+                cs5535_mfgpt_toggle_event(&t, MFGPT_CMP1, MFGPT_EVENT_RESET, 0);
+                cs5535_mfgpt_toggle_event(&t, MFGPT_CMP2, MFGPT_EVENT_RESET, 0);
+                cs5535_mfgpt_toggle_event(&t, MFGPT_CMP1, MFGPT_EVENT_NMI, 0);
+                cs5535_mfgpt_toggle_event(&t, MFGPT_CMP2, MFGPT_EVENT_NMI, 0);
+                cs5535_mfgpt_toggle_event(&t, MFGPT_CMP1, MFGPT_EVENT_IRQ, 0);
+                cs5535_mfgpt_toggle_event(&t, MFGPT_CMP2, MFGPT_EVENT_IRQ, 0);
+        }
+}
+
+/*
  * Check whether any MFGPTs are available for the kernel to use.  In most
  * cases, firmware that uses AMD's VSA code will claim all timers during
  * bootup; we certainly don't want to take them if they're already in use.
@@ -271,15 +296,17 @@ static int scan_timers(struct cs5535_mfgpt_chip *mfgpt)
         int i;
 
         /* bios workaround */
-        if (mfgpt_reset_timers)
+        if (mfgpt_reset_timers == 1)
                 reset_all_timers();
+        else if (mfgpt_reset_timers == 2)
+                soft_reset();
 
         /* just to be safe, protect this section w/ lock */
         spin_lock_irqsave(&mfgpt->lock, flags);
         for (i = 0; i < MFGPT_MAX_TIMERS; i++) {
                 timer.nr = i;
                 val = cs5535_mfgpt_read(&timer, MFGPT_REG_SETUP);
-                if (!(val & MFGPT_SETUP_SETUP)) {
+                if (!(val & MFGPT_SETUP_SETUP) || mfgpt_reset_timers == 2) {
                         __set_bit(i, mfgpt->avail);
                         timers++;
                 }
@@ -294,6 +321,12 @@ static int cs5535_mfgpt_probe(struct platform_device *pdev)
         struct resource *res;
         int err = -EIO, t;
 
+        if (mfgpt_reset_timers < 0 || mfgpt_reset_timers > 2) {
+                dev_err(&pdev->dev, "Bad mfgpt_reset_timers value: %i\n",
+                        mfgpt_reset_timers);
+                goto done;
+        }
+
         /* There are two ways to get the MFGPT base address; one is by
          * fetching it from MSR_LBAR_MFGPT, the other is by reading the
          * PCI BAR info.  The latter method is easier (especially across