ath9k: improve suspend/resume reliability

Ensure that drv_start() always returns true, as a failing hw start usually
eventually leads to crashes when there's still a station entry present.
Call a power-on reset after a resume and after a hw reset failure to bring
the hardware back to life again.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 13 insertions, 10 deletions

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index f9a6ec5cf470..8e1559aba495 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1450,9 +1450,14 @@ static bool ath9k_hw_set_reset_reg(struct ath_hw *ah, u32 type)
         REG_WRITE(ah, AR_RTC_FORCE_WAKE,
                   AR_RTC_FORCE_WAKE_EN | AR_RTC_FORCE_WAKE_ON_INT);
 
+        if (!ah->reset_power_on)
+                type = ATH9K_RESET_POWER_ON;
+
         switch (type) {
         case ATH9K_RESET_POWER_ON:
                 ret = ath9k_hw_set_reset_power_on(ah);
+                if (!ret)
+                        ah->reset_power_on = true;
                 break;
         case ATH9K_RESET_WARM:
         case ATH9K_RESET_COLD:
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 566a4ce4f156..dbc1b7a4cbfd 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -741,6 +741,7 @@ struct ath_hw {
         u32 rfkill_polarity;
         u32 ah_flags;
 
+        bool reset_power_on;
         bool htc_reset_init;
 
         enum nl80211_iftype opmode;
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 31ab82e3ba85..e2fe713235dc 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -639,8 +639,7 @@ static int ath9k_start(struct ieee80211_hw *hw)
                 ath_err(common,
                         "Unable to reset hardware; reset status %d (freq %u MHz)\n",
                         r, curchan->center_freq);
-                spin_unlock_bh(&sc->sc_pcu_lock);
-                goto mutex_unlock;
+                ah->reset_power_on = false;
         }
 
         /* Setup our intr mask. */
@@ -665,11 +664,8 @@ static int ath9k_start(struct ieee80211_hw *hw)
         clear_bit(SC_OP_INVALID, &sc->sc_flags);
         sc->sc_ah->is_monitoring = false;
 
-        if (!ath_complete_reset(sc, false)) {
-                r = -EIO;
-                spin_unlock_bh(&sc->sc_pcu_lock);
-                goto mutex_unlock;
-        }
+        if (!ath_complete_reset(sc, false))
+                ah->reset_power_on = false;
 
         if (ah->led_pin >= 0) {
                 ath9k_hw_cfg_output(ah, ah->led_pin,
@@ -688,12 +684,11 @@ static int ath9k_start(struct ieee80211_hw *hw)
         if (ah->caps.pcie_lcr_extsync_en && common->bus_ops->extn_synch_en)
                 common->bus_ops->extn_synch_en(common);
 
-mutex_unlock:
         mutex_unlock(&sc->mutex);
 
         ath9k_ps_restore(sc);
 
-        return r;
+        return 0;
 }
 
 static void ath9k_tx(struct ieee80211_hw *hw,
diff --git a/drivers/net/wireless/ath/ath9k/pci.c b/drivers/net/wireless/ath/ath9k/pci.c
index 270abf720f3e..f088f4bf9a26 100644
--- a/drivers/net/wireless/ath/ath9k/pci.c
+++ b/drivers/net/wireless/ath/ath9k/pci.c
@@ -326,7 +326,8 @@ static int ath_pci_resume(struct device *device)
         struct pci_dev *pdev = to_pci_dev(device);
         struct ieee80211_hw *hw = pci_get_drvdata(pdev);
         struct ath_softc *sc = hw->priv;
-        struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+        struct ath_hw *ah = sc->sc_ah;
+        struct ath_common *common = ath9k_hw_common(ah);
         u32 val;
 
         /*
@@ -339,6 +340,7 @@ static int ath_pci_resume(struct device *device)
                 pci_write_config_dword(pdev, 0x40, val & 0xffff00ff);
 
         ath_pci_aspm_init(common);
+        ah->reset_power_on = false;
 
         return 0;
 }