[PATCH 3.14 53/94] iwlwifi: pcie: try to get ownership several times

From: Greg Kroah-Hartman
Date: Mon Jul 07 2014 - 20:25:38 EST


3.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/iwlwifi/pcie/trans.c | 30 ++++++++++++++++++------------
1 file changed, 18 insertions(+), 12 deletions(-)

--- 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(stru
{
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(stru
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);
-
- do {
- ret = iwl_pcie_set_hw_ready(trans);
- if (ret >= 0)
- return 0;
-
- usleep_range(200, 1000);
- t += 200;
- } while (t < 150000);
+ 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;
+
+ usleep_range(200, 1000);
+ t += 200;
+ } while (t < 150000);
+ msleep(25);
+ }
+
+ IWL_DEBUG_INFO(trans, "got NIC after %d iterations\n", iter);

return ret;
}


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