iwlagn: enable only rfkill interrupt when device is down

commit 554d1d027b19265c4aa3f718b3126d2b86e09a08 upstream.

Since commit 6cd0b1cb872b3bf9fc5de4536404206ab74bafdd "iwlagn: fix
hw-rfkill while the interface is down", we enable interrupts when
device is not ready to receive them. However hardware, when it is in
some inconsistent state, can generate other than rfkill interrupts
and crash the system. I can reproduce crash with "kernel BUG at
drivers/net/wireless/iwlwifi/iwl-agn.c:1010!" message, when forcing
firmware restarts.

To fix only enable rfkill interrupt when down device and after probe.
I checked patch on laptop with 5100 device, rfkill change is still
passed to user space when device is down.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index c7f56b4aeb89d37282cb8150a7b9a4db72a53b4e..6aa261402f882f60a6be5de37ca1a97a77c9acee 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -3112,9 +3112,10 @@ static void iwl_mac_stop(struct ieee80211_hw *hw)
 
        flush_workqueue(priv->workqueue);
 
-       /* enable interrupts again in order to receive rfkill changes */
+       /* User space software may expect getting rfkill changes
+        * even if interface is down */
        iwl_write32(priv, CSR_INT, 0xFFFFFFFF);
-       iwl_enable_interrupts(priv);
+       iwl_enable_rfkill_int(priv);
 
        IWL_DEBUG_MAC80211(priv, "leave\n");
 }
@@ -3832,14 +3833,14 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
         * 8. Enable interrupts and read RFKILL state
         *********************************************/
 
-       /* enable interrupts if needed: hw bug w/a */
+       /* enable rfkill interrupt: hw bug w/a */
        pci_read_config_word(priv->pci_dev, PCI_COMMAND, &pci_cmd);
        if (pci_cmd & PCI_COMMAND_INTX_DISABLE) {
                pci_cmd &= ~PCI_COMMAND_INTX_DISABLE;
                pci_write_config_word(priv->pci_dev, PCI_COMMAND, pci_cmd);
        }
 
-       iwl_enable_interrupts(priv);
+       iwl_enable_rfkill_int(priv);
 
        /* If platform's RF_KILL switch is NOT set to KILL */
        if (iwl_read32(priv, CSR_GP_CNTRL) & CSR_GP_CNTRL_REG_FLAG_HW_RF_KILL_SW)

diff --git a/drivers/net/wireless/iwlwifi/iwl-helpers.h b/drivers/net/wireless/iwlwifi/iwl-helpers.h
index 3ff6b9d25a10665397c5b87285207d5591293993..2f7ea66c1ed311f0f10da5823ba5f448a944477e 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-helpers.h
+++ b/drivers/net/wireless/iwlwifi/iwl-helpers.h
@@ -163,6 +163,12 @@ static inline void iwl_disable_interrupts(struct iwl_priv *priv)
        IWL_DEBUG_ISR(priv, "Disabled interrupts\n");
 }
 
+static inline void iwl_enable_rfkill_int(struct iwl_priv *priv)
+{
+       IWL_DEBUG_ISR(priv, "Enabling rfkill interrupt\n");
+       iwl_write32(priv, CSR_INT_MASK, CSR_INT_BIT_RF_KILL);
+}
+
 static inline void iwl_enable_interrupts(struct iwl_priv *priv)
 {
        IWL_DEBUG_ISR(priv, "Enabling interrupts\n");