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>

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 166bedd3c615b497fc9b69580a2089e77dcd24a6..70f12ecc4f91cc0c8e799ab71321cbd6e793ed49 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -2358,9 +2358,10 @@ 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");
 }
@@ -3060,14 +3061,14 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
         * 8. Setup and register mac80211
         **********************************/
 
-       /* 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);
 
        err = iwl_setup_mac(priv);
        if (err)

diff --git a/drivers/net/wireless/iwlwifi/iwl-helpers.h b/drivers/net/wireless/iwlwifi/iwl-helpers.h
index f8481e8bf04a75220609d1c9d824f8dc808a4d28..bf2a33fa1c847e3302ffa0903bffd6549e17bb3a 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-helpers.h
+++ b/drivers/net/wireless/iwlwifi/iwl-helpers.h
@@ -160,6 +160,12 @@ 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");