Re: [PATCH 3/4] ath5k: Wakeup fixes

[Nick Kossifidis <mick@madwifi-project.org>]

 * Don't put chip to full sleep because there are problems during
   wakeup. Instead hold MAC/Baseband on warm reset state via a new
   function ath5k_hw_on_hold.

 * Durring attach preserve pcicfg bits when enabling pci core
   sw retry fix.

 * Minor cleanups

 Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>

---
 drivers/net/wireless/ath/ath5k/ath5k.h  |    1 +
 drivers/net/wireless/ath/ath5k/attach.c |    4 +-
 drivers/net/wireless/ath/ath5k/base.c   |   44 +++++----
 drivers/net/wireless/ath/ath5k/reset.c  |  155 +++++++++++++++++++++++--------
 4 files changed, 141 insertions(+), 63 deletions(-)

diff --git a/drivers/net/wireless/ath/ath5k/ath5k.h b/drivers/net/wireless/ath/ath5k/ath5k.h
index 9137511..1047a6c 100644
--- a/drivers/net/wireless/ath/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath/ath5k/ath5k.h
@@ -1157,6 +1157,7 @@ extern void ath5k_unregister_leds(struct ath5k_softc *sc);
 
 /* Reset Functions */
 extern int ath5k_hw_nic_wakeup(struct ath5k_hw *ah, int flags, bool initial);
+extern int ath5k_hw_on_hold(struct ath5k_hw *ah);
 extern int ath5k_hw_reset(struct ath5k_hw *ah, enum nl80211_iftype op_mode, struct ieee80211_channel *channel, bool change_channel);
 /* Power management functions */
 extern int ath5k_hw_set_power(struct ath5k_hw *ah, enum ath5k_power_mode mode, bool set_chip, u16 sleep_duration);
diff --git a/drivers/net/wireless/ath/ath5k/attach.c b/drivers/net/wireless/ath/ath5k/attach.c
index 6263065..65d438b 100644
--- a/drivers/net/wireless/ath/ath5k/attach.c
+++ b/drivers/net/wireless/ath/ath5k/attach.c
@@ -145,7 +145,7 @@ struct ath5k_hw *ath5k_hw_attach(struct ath5k_softc *sc, u8 mac_version)
 		goto err_free;
 
 	/* Bring device out of sleep and reset it's units */
-	ret = ath5k_hw_nic_wakeup(ah, CHANNEL_B, true);
+	ret = ath5k_hw_nic_wakeup(ah, 0, true);
 	if (ret)
 		goto err_free;
 
@@ -261,7 +261,7 @@ struct ath5k_hw *ath5k_hw_attach(struct ath5k_softc *sc, u8 mac_version)
 
 	/* Enable pci core retry fix on Hainan (5213A) and later chips */
 	if (srev >= AR5K_SREV_AR5213A)
-		ath5k_hw_reg_write(ah, AR5K_PCICFG_RETRY_FIX, AR5K_PCICFG);
+		AR5K_REG_ENABLE_BITS(ah, AR5K_PCICFG, AR5K_PCICFG_RETRY_FIX);
 
 	/*
 	 * Get card capabilities, calibration values etc
diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index 7db32ce..b64731b 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -2448,27 +2448,29 @@ ath5k_stop_hw(struct ath5k_softc *sc)
 	ret = ath5k_stop_locked(sc);
 	if (ret == 0 && !test_bit(ATH_STAT_INVALID, sc->status)) {
 		/*
-		 * Set the chip in full sleep mode.  Note that we are
-		 * careful to do this only when bringing the interface
-		 * completely to a stop.  When the chip is in this state
-		 * it must be carefully woken up or references to
-		 * registers in the PCI clock domain may freeze the bus
-		 * (and system).  This varies by chip and is mostly an
-		 * issue with newer parts that go to sleep more quickly.
-		 */
-		if (sc->ah->ah_mac_srev >= 0x78) {
-			/*
-			 * XXX
-			 * don't put newer MAC revisions > 7.8 to sleep because
-			 * of the above mentioned problems
-			 */
-			ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "mac version > 7.8, "
-				"not putting device to sleep\n");
-		} else {
-			ATH5K_DBG(sc, ATH5K_DEBUG_RESET,
-				"putting device to full sleep\n");
-			ath5k_hw_set_power(sc->ah, AR5K_PM_FULL_SLEEP, true, 0);
-		}
+		 * Don't set the card in full sleep mode!
+		 *
+		 * a) When the device is in this state it must be carefully
+		 * woken up or references to registers in the PCI clock
+		 * domain may freeze the bus (and system).  This varies
+		 * by chip and is mostly an issue with newer parts
+		 * (madwifi sources mentioned srev >= 0x78) that go to
+		 * sleep more quickly.
+		 *
+		 * b) On older chips full sleep results a weird behaviour
+		 * during wakeup. I tested various cards with srev < 0x78
+		 * and they don't wake up after module reload, a second
+		 * module reload is needed to bring the card up again.
+		 *
+		 * Until we figure out what's going on don't enable
+		 * full chip reset on any chip (this is what Legacy HAL
+		 * and Sam's HAL do anyway). Instead Perform a full reset
+		 * on the device (same as initial state after attach) and
+		 * leave it idle (keep MAC/BB on warm reset) */
+		ret = ath5k_hw_on_hold(sc->ah);
+
+		ATH5K_DBG(sc, ATH5K_DEBUG_RESET,
+				"putting device to sleep\n");
 	}
 	ath5k_txbuf_free(sc, sc->bbuf);
 
diff --git a/drivers/net/wireless/ath/ath5k/reset.c b/drivers/net/wireless/ath/ath5k/reset.c
index 86733fd..34e13c7 100644
--- a/drivers/net/wireless/ath/ath5k/reset.c
+++ b/drivers/net/wireless/ath/ath5k/reset.c
@@ -258,29 +258,35 @@ int ath5k_hw_set_power(struct ath5k_hw *ah, enum ath5k_power_mode mode,
 		if (!set_chip)
 			goto commit;
 
-		/* Preserve sleep duration */
 		data = ath5k_hw_reg_read(ah, AR5K_SLEEP_CTL);
+
+		/* If card is down we 'll get 0xffff... so we
+		 * need to clean this up before we write the register
+		 */
 		if (data & 0xffc00000)
 			data = 0;
 		else
-			data = data & 0xfffcffff;
+			/* Preserve sleep duration etc */
+			data = data & ~AR5K_SLEEP_CTL_SLE;
 
-		ath5k_hw_reg_write(ah, data, AR5K_SLEEP_CTL);
+		ath5k_hw_reg_write(ah, data | AR5K_SLEEP_CTL_SLE_WAKE,
+							AR5K_SLEEP_CTL);
 		udelay(15);
 
-		for (i = 50; i > 0; i--) {
+		for (i = 200; i > 0; i--) {
 			/* Check if the chip did wake up */
 			if ((ath5k_hw_reg_read(ah, AR5K_PCICFG) &
 					AR5K_PCICFG_SPWR_DN) == 0)
 				break;
 
 			/* Wait a bit and retry */
-			udelay(200);
-			ath5k_hw_reg_write(ah, data, AR5K_SLEEP_CTL);
+			udelay(50);
+			ath5k_hw_reg_write(ah, data | AR5K_SLEEP_CTL_SLE_WAKE,
+							AR5K_SLEEP_CTL);
 		}
 
 		/* Fail if the chip didn't wake up */
-		if (i <= 0)
+		if (i == 0)
 			return -EIO;
 
 		break;
@@ -296,6 +302,64 @@ commit:
 }
 
 /*
+ * Put device on hold
+ *
+ * Put MAC and Baseband on warm reset and
+ * keep that state (don't clean sleep control
+ * register). After this MAC and Baseband are
+ * disabled and a full reset is needed to come
+ * back. This way we save as much power as possible
+ * without puting the card on full sleep.
+ */
+int ath5k_hw_on_hold(struct ath5k_hw *ah)
+{
+	struct pci_dev *pdev = ah->ah_sc->pdev;
+	u32 bus_flags;
+	int ret;
+
+	/* Make sure device is awake */
+	ret = ath5k_hw_set_power(ah, AR5K_PM_AWAKE, true, 0);
+	if (ret) {
+		ATH5K_ERR(ah->ah_sc, "failed to wakeup the MAC Chip\n");
+		return ret;
+	}
+
+	/*
+	 * Put chipset on warm reset...
+	 *
+	 * Note: puting PCI core on warm reset on PCI-E cards
+	 * results card to hang and always return 0xffff... so
+	 * we ingore that flag for PCI-E cards. On PCI cards
+	 * this flag gets cleared after 64 PCI clocks.
+	 */
+	bus_flags = (pdev->is_pcie) ? 0 : AR5K_RESET_CTL_PCI;
+
+	if (ah->ah_version == AR5K_AR5210) {
+		ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
+			AR5K_RESET_CTL_MAC | AR5K_RESET_CTL_DMA |
+			AR5K_RESET_CTL_PHY | AR5K_RESET_CTL_PCI);
+			mdelay(2);
+	} else {
+		ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
+			AR5K_RESET_CTL_BASEBAND | bus_flags);
+	}
+
+	if (ret) {
+		ATH5K_ERR(ah->ah_sc, "failed to put device on warm reset\n");
+		return -EIO;
+	}
+
+	/* ...wakeup again!*/
+	ret = ath5k_hw_set_power(ah, AR5K_PM_AWAKE, true, 0);
+	if (ret) {
+		ATH5K_ERR(ah->ah_sc, "failed to put device on hold\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+/*
  * Bring up MAC + PHY Chips and program PLL
  * TODO: Half/Quarter rate support
  */
@@ -318,6 +382,50 @@ int ath5k_hw_nic_wakeup(struct ath5k_hw *ah, int flags, bool initial)
 		return ret;
 	}
 
+	/*
+	 * Put chipset on warm reset...
+	 *
+	 * Note: puting PCI core on warm reset on PCI-E cards
+	 * results card to hang and always return 0xffff... so
+	 * we ingore that flag for PCI-E cards. On PCI cards
+	 * this flag gets cleared after 64 PCI clocks.
+	 */
+	bus_flags = (pdev->is_pcie) ? 0 : AR5K_RESET_CTL_PCI;
+
+	if (ah->ah_version == AR5K_AR5210) {
+		ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
+			AR5K_RESET_CTL_MAC | AR5K_RESET_CTL_DMA |
+			AR5K_RESET_CTL_PHY | AR5K_RESET_CTL_PCI);
+			mdelay(2);
+	} else {
+		ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
+			AR5K_RESET_CTL_BASEBAND | bus_flags);
+	}
+
+	if (ret) {
+		ATH5K_ERR(ah->ah_sc, "failed to reset the MAC Chip\n");
+		return -EIO;
+	}
+
+	/* ...wakeup again!...*/
+	ret = ath5k_hw_set_power(ah, AR5K_PM_AWAKE, true, 0);
+	if (ret) {
+		ATH5K_ERR(ah->ah_sc, "failed to resume the MAC Chip\n");
+		return ret;
+	}
+
+	/* ...clear reset control register and pull device out of
+	 * warm reset */
+	if (ath5k_hw_nic_reset(ah, 0)) {
+		ATH5K_ERR(ah->ah_sc, "failed to warm reset the MAC Chip\n");
+		return -EIO;
+	}
+
+	/* On initialization skip PLL programming since we don't have
+	 * a channel / mode set yet */
+	if (initial)
+		return 0;
+
 	if (ah->ah_version != AR5K_AR5210) {
 		/*
 		 * Get channel mode flags
@@ -383,39 +491,6 @@ int ath5k_hw_nic_wakeup(struct ath5k_hw *ah, int flags, bool initial)
 					AR5K_PHY_TURBO);
 	}
 
-	/* reseting PCI on PCI-E cards results card to hang
-	 * and always return 0xffff... so we ingore that flag
-	 * for PCI-E cards */
-	bus_flags = (pdev->is_pcie) ? 0 : AR5K_RESET_CTL_PCI;
-
-	/* Reset chipset */
-	if (ah->ah_version == AR5K_AR5210) {
-		ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
-			AR5K_RESET_CTL_MAC | AR5K_RESET_CTL_DMA |
-			AR5K_RESET_CTL_PHY | AR5K_RESET_CTL_PCI);
-			mdelay(2);
-	} else {
-		ret = ath5k_hw_nic_reset(ah, AR5K_RESET_CTL_PCU |
-			AR5K_RESET_CTL_BASEBAND | bus_flags);
-	}
-	if (ret) {
-		ATH5K_ERR(ah->ah_sc, "failed to reset the MAC Chip\n");
-		return -EIO;
-	}
-
-	/* ...wakeup again!*/
-	ret = ath5k_hw_set_power(ah, AR5K_PM_AWAKE, true, 0);
-	if (ret) {
-		ATH5K_ERR(ah->ah_sc, "failed to resume the MAC Chip\n");
-		return ret;
-	}
-
-	/* ...final warm reset */
-	if (ath5k_hw_nic_reset(ah, 0)) {
-		ATH5K_ERR(ah->ah_sc, "failed to warm reset the MAC Chip\n");
-		return -EIO;
-	}
-
 	if (ah->ah_version != AR5K_AR5210) {
 
 		/* ...update PLL if needed */