iwlwifi: pcie: try to get ownership several times

commit 501fd9895c1d7d8161ed56698ae2fccb10ef14f5 upstream.

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

Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 8d42fd9b0811034089244409ccb7ecac7d5f5146..16be0c07c64a32e2ecb69548415149911a27808c 100644 (file)
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -318,6 +318,7 @@ 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");
 
@@ -326,18 +327,23 @@ 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;
 }