[ath9k-devel] ath9k: massive unexplained latency in 2.6.27 (rc5, rc6, probably others)

[Luis R. Rodriguez <lrodriguez@atheros.com>]

On Fri, Sep 19, 2008 at 10:58:24AM -0700, Senthilkumar Balasubramanian wrote:
> 
> I am on 2.6.27-rc6 and this patch is on top of my earlier patch
> titled "[PATCH] ath9k: connectivity is lost after Group rekeying is
> done". However this patch can be applied on top of latest wireless testing
> too. I could apply this patch succesfully on top of wireless testing
> git tree.
> 
> My git-describe says v2.6.27-rc6-1378-g34e512f.
> 
> There is no sc_invalid flag in "struct ath_softc" today. Where did
> you get this variable from? It was removed in the following commit
> 
> -----------------------------------------------
> commit f2c9705a05ecbc0d94216a3b042d5641e8bf70b1
> Author: Sujith <Sujith.Manoharan@atheros.com>
> Date:   Mon Aug 11 14:05:08 2008 +0530
> 
>     ath9k: Use bitfields for sc operations
> 
>     Signed-off-by: Sujith Manoharan <Sujith.Manoharan@atheros.com>
>     Signed-off-by: John W. Linville <linville@tuxdriver.com>
> -----------------------------------------------
> 
> Which code base are you using?

Thanks for the patch Senthil. He is on Linus' v2.6.27-rc, you are on
wireless-testing so I've ported it (no changes, it just applies cleanly
now). This is also untested by me:

diff --git a/drivers/net/wireless/ath9k/core.c b/drivers/net/wireless/ath9k/core.c
index f6c4528..9a432e5 100644
--- a/drivers/net/wireless/ath9k/core.c
+++ b/drivers/net/wireless/ath9k/core.c
@@ -1336,6 +1336,8 @@ void ath_deinit(struct ath_softc *sc)
 
 	DPRINTF(sc, ATH_DBG_CONFIG, "%s\n", __func__);
 
+	tasklet_kill(&sc->intr_tq);
+	tasklet_kill(&sc->bcon_tasklet);
 	ath_stop(sc);
 	if (!sc->sc_invalid)
 		ath9k_hw_setpower(sc->sc_ah, ATH9K_PM_AWAKE);
diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index c5107f2..75acf54 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -1400,10 +1400,16 @@ static void ath_pci_remove(struct pci_dev *pdev)
 {
 	struct ieee80211_hw *hw = pci_get_drvdata(pdev);
 	struct ath_softc *sc = hw->priv;
+	enum ath9k_int status;
 
-	if (pdev->irq)
+	if (pdev->irq) {
+		ath9k_hw_set_interrupts(sc->sc_ah, 0);
+		ath9k_hw_getisr(sc->sc_ah, &status);	/* NB: clears ISR too */
+		sc->sc_flags |= SC_OP_INVALID;
 		free_irq(pdev->irq, sc);
+	}
 	ath_detach(sc);
+
 	pci_iounmap(pdev, sc->mem);
 	pci_release_region(pdev, 0);
 	pci_disable_device(pdev);