iwlwifi: pcie: keep the NIC awake when commands are in flight

Under very specific circumstances, the firmware might
ignore a host command. This was debugged and we ended up
seeing that the power management hardware was faulty.
In order to workaround this issue, we keep the NIC awake
as long as we have host commands in flight. This will avoid
to put the hardware into buggy condition.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 8 insertions, 27 deletions

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 9a07cf3062ea..d9ccb4edc602 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -75,33 +75,6 @@
 #include "iwl-agn-hw.h"
 #include "internal.h"
 
-static void __iwl_trans_pcie_set_bits_mask(struct iwl_trans *trans,
-						  u32 reg, u32 mask, u32 value)
-{
-	u32 v;
-
-#ifdef CONFIG_IWLWIFI_DEBUG
-	WARN_ON_ONCE(value & ~mask);
-#endif
-
-	v = iwl_read32(trans, reg);
-	v &= ~mask;
-	v |= value;
-	iwl_write32(trans, reg, v);
-}
-
-static inline void __iwl_trans_pcie_clear_bit(struct iwl_trans *trans,
-					      u32 reg, u32 mask)
-{
-	__iwl_trans_pcie_set_bits_mask(trans, reg, mask, 0);
-}
-
-static inline void __iwl_trans_pcie_set_bit(struct iwl_trans *trans,
-					    u32 reg, u32 mask)
-{
-	__iwl_trans_pcie_set_bits_mask(trans, reg, mask, mask);
-}
-
 static void iwl_pcie_set_pwr(struct iwl_trans *trans, bool vaux)
 {
 	if (vaux && pci_pme_capable(to_pci_dev(trans->dev), PCI_D3cold))
@@ -929,6 +902,9 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans, bool silent,
 
 	spin_lock_irqsave(&trans_pcie->reg_lock, *flags);
 
+	if (trans_pcie->cmd_in_flight)
+		goto out;
+
 	/* this bit wakes up the NIC */
 	__iwl_trans_pcie_set_bit(trans, CSR_GP_CNTRL,
 				 CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
@@ -968,6 +944,7 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans, bool silent,
 		}
 	}
 
+out:
 	/*
 	 * Fool sparse by faking we release the lock - sparse will
 	 * track nic_access anyway.
@@ -989,6 +966,9 @@ static void iwl_trans_pcie_release_nic_access(struct iwl_trans *trans,
 	 */
 	__acquire(&trans_pcie->reg_lock);
 
+	if (trans_pcie->cmd_in_flight)
+		goto out;
+
 	__iwl_trans_pcie_clear_bit(trans, CSR_GP_CNTRL,
 				   CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
 	/*
@@ -998,6 +978,7 @@ static void iwl_trans_pcie_release_nic_access(struct iwl_trans *trans,
 	 * scheduled on different CPUs (after we drop reg_lock).
 	 */
 	mmiowb();
+out:
 	spin_unlock_irqrestore(&trans_pcie->reg_lock, *flags);
 }