iwlwifi: pcie: try to get ownership several times

Some races with the hardware can happen when we take
ownership of the device. Don't give up after the first try.

Cc: <stable@vger.kernel.org>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index f41f9b7a6007894d2e79e5150cfdce3ae10d462f..f8ebd477bbfccdf11f499fa16f9bc5ae70672fa5 100644 (file)
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -454,6 +454,7 @@ static int iwl_pcie_prepare_card_hw(struct iwl_trans *trans)
 {
        int ret;
        int t = 0;
+       int iter;
 
        IWL_DEBUG_INFO(trans, "iwl_trans_prepare_card_hw enter\n");
 
@@ -462,18 +463,23 @@ static int iwl_pcie_prepare_card_hw(struct iwl_trans *trans)
        if (ret >= 0)
                return 0;
 
-       /* If HW is not ready, prepare the conditions to check again */
-       iwl_set_bit(trans, CSR_HW_IF_CONFIG_REG,
-                   CSR_HW_IF_CONFIG_REG_PREPARE);
+       for (iter = 0; iter < 10; iter++) {
+               /* If HW is not ready, prepare the conditions to check again */
+               iwl_set_bit(trans, CSR_HW_IF_CONFIG_REG,
+                           CSR_HW_IF_CONFIG_REG_PREPARE);
+
+               do {
+                       ret = iwl_pcie_set_hw_ready(trans);
+                       if (ret >= 0)
+                               return 0;
 
-       do {
-               ret = iwl_pcie_set_hw_ready(trans);
-               if (ret >= 0)
-                       return 0;
+                       usleep_range(200, 1000);
+                       t += 200;
+               } while (t < 150000);
+               msleep(25);
+       }
 
-               usleep_range(200, 1000);
-               t += 200;
-       } while (t < 150000);
+       IWL_DEBUG_INFO(trans, "got NIC after %d iterations\n", iter);
 
        return ret;
 }