b43: Add panic reason code that doesn't trigger restart

Add a firmware panic reason code that doesn't trigger a restart.
This is useful for firmware debugging and avoiding endless
restart loops. We can use FWPANIC_DIE to halt the firmware at a
well defined point.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 31 insertions, 8 deletions

diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 6011747bb3b9..e1dfb4074676 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -1662,6 +1662,30 @@ static void b43_set_beacon_int(struct b43_wldev *dev, u16 beacon_int)
         b43dbg(dev->wl, "Set beacon interval to %u\n", beacon_int);
 }
 
+static void b43_handle_firmware_panic(struct b43_wldev *dev)
+{
+        u16 reason;
+
+        /* Read the register that contains the reason code for the panic. */
+        reason = b43_shm_read16(dev, B43_SHM_SCRATCH, B43_FWPANIC_REASON_REG);
+        b43err(dev->wl, "Whoopsy, firmware panic! Reason: %u\n", reason);
+
+        switch (reason) {
+        default:
+                b43dbg(dev->wl, "The panic reason is unknown.\n");
+                /* fallthrough */
+        case B43_FWPANIC_DIE:
+                /* Do not restart the controller or firmware.
+                 * The device is nonfunctional from now on.
+                 * Restarting would result in this panic to trigger again,
+                 * so we avoid that recursion. */
+                break;
+        case B43_FWPANIC_RESTART:
+                b43_controller_restart(dev, "Microcode panic");
+                break;
+        }
+}
+
 static void handle_irq_ucode_debug(struct b43_wldev *dev)
 {
         unsigned int i, cnt;
@@ -1672,15 +1696,12 @@ static void handle_irq_ucode_debug(struct b43_wldev *dev)
         if (!dev->fw.opensource)
                 return;
 
-        /* Microcode register 63 contains the debug-IRQ reason. */
-        reason = b43_shm_read16(dev, B43_SHM_SCRATCH, 63);
+        /* Read the register that contains the reason code for this IRQ. */
+        reason = b43_shm_read16(dev, B43_SHM_SCRATCH, B43_DEBUGIRQ_REASON_REG);
+
         switch (reason) {
         case B43_DEBUGIRQ_PANIC:
-                /* The reason for the panic is in register 3. */
-                reason = b43_shm_read16(dev, B43_SHM_SCRATCH, 3);
-                b43err(dev->wl, "Whoopsy, the microcode panic'ed! Reason: %u\n",
-                       reason);
-                b43_controller_restart(dev, "Microcode panic");
+                b43_handle_firmware_panic(dev);
                 break;
         case B43_DEBUGIRQ_DUMP_SHM:
                 if (!B43_DEBUG)
@@ -1721,7 +1742,9 @@ static void handle_irq_ucode_debug(struct b43_wldev *dev)
                        reason);
         }
 out:
-        b43_shm_write16(dev, B43_SHM_SCRATCH, 63, B43_DEBUGIRQ_ACK);
+        /* Acknowledge the debug-IRQ, so the firmware can continue. */
+        b43_shm_write16(dev, B43_SHM_SCRATCH,
+                        B43_DEBUGIRQ_REASON_REG, B43_DEBUGIRQ_ACK);
 }
 
 /* Interrupt handler bottom-half */