Attachment 609744 Details for Bug 787649 – using waitqueue to wait for flush completion

[patch] using waitqueue to wait for flush completion

0001-brcmsmac-rework-of-mac80211-.flush-callback-operatio.patch (text/plain), 7.14 KB, created by brcm80211 driver developers on 2012-09-04 16:47:54 UTC

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Creator: brcm80211 driver developers

Created: 2012-09-04 16:47:54 UTC

Size: 7.14 KB

patch

obsolete

>From 9ce7cd0cae3058c9057fa2e7036c38769efa8a3b Mon Sep 17 00:00:00 2001
>From: Arend van Spriel <arend@broadcom.com>
>Date: Fri, 31 Aug 2012 16:00:10 +0200
>Subject: [PATCH] brcmsmac: rework of mac80211 .flush() callback operation
>MIME-Version: 1.0
>Content-Type: text/plain; charset=UTF-8
>Content-Transfer-Encoding: 8bit
>
>This patch addresses a long standing issue of the driver with the
>mac80211 .flush() callback. Since implementing the .flush() callback
>a number of issues have been fixed, but a WARN_ON_ONCE() was still
>triggered because the flush takes too much time. The flush now
>makes use of a waitqueue and still has a timeout on which a warning
>is given.
>
>bugzilla: 42840 <https://bugzilla.kernel.org/show_bug.cgi?id=42840>
>bugzilla@redhat: <https://bugzilla.redhat.com/show_bug.cgi?id=799168>
>bugzilla@redhat: <https://bugzilla.redhat.com/show_bug.cgi?id=787649>
>
>Cc: stable <stable@vger.kernel.org>
>Cc: Jonathan Nieder <jrnieder@gmail.com>
>Cc: Stanislaw Gruszka <sgruszka@redhat.com>
>Cc: CamaleÃ³n <noelamac@gmail.com>
>Cc: Milan Bouchet-Valat <nalimilan@club-internet.fr>
>Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
>Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
>Signed-off-by: Arend van Spriel <arend@broadcom.com>
>---
> .../net/wireless/brcm80211/brcmsmac/mac80211_if.c  |   41 +++++++++++++-------
> .../net/wireless/brcm80211/brcmsmac/mac80211_if.h  |    3 +-
> drivers/net/wireless/brcm80211/brcmsmac/main.c     |   21 +++-------
> drivers/net/wireless/brcm80211/brcmsmac/pub.h      |    4 +-
> 4 files changed, 37 insertions(+), 32 deletions(-)
>
>diff --git a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
>index 192ad5c..d2e2fc5 100644
>--- a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
>+++ b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.c
>@@ -35,6 +35,7 @@
> #include "main.h"
> 
> #define N_TX_QUEUES	4 /* #tx queues on mac80211<->driver interface */
>+#define BRCMS_FLUSH_TIMEOUT	100 /* msec */
> 
> /* Flags we support */
> #define MAC_FILTERS (FIF_PROMISC_IN_BSS | \
>@@ -693,16 +694,35 @@ static void brcms_ops_rfkill_poll(struct ieee80211_hw *hw)
> 	wiphy_rfkill_set_hw_state(wl->pub->ieee_hw->wiphy, blocked);
> }
> 
>+static bool brcms_tx_flush_completed(struct brcms_info *wl)
>+{
>+	bool result;
>+
>+	spin_lock_bh(&wl->lock);
>+	result = brcms_c_tx_flush_completed(wl->wlc);
>+	spin_unlock_bh(&wl->lock);
>+	return result;
>+}
>+
> static void brcms_ops_flush(struct ieee80211_hw *hw, bool drop)
> {
> 	struct brcms_info *wl = hw->priv;
>+	int ret;
> 
> 	no_printk("%s: drop = %s\n", __func__, drop ? "true" : "false");
> 
>-	/* wait for packet queue and dma fifos to run empty */
>-	spin_lock_bh(&wl->lock);
>-	brcms_c_wait_for_tx_completion(wl->wlc, drop);
>-	spin_unlock_bh(&wl->lock);
>+	ieee80211_stop_queues(hw);
>+	if (drop) {
>+		spin_lock_bh(&wl->lock);
>+		brcms_c_pktq_flush(wl->wlc);
>+		spin_unlock_bh(&wl->lock);
>+	}
>+	ret = wait_event_timeout(wl->tx_flush_wq,
>+				 brcms_tx_flush_completed(wl),
>+				 msecs_to_jiffies(BRCMS_FLUSH_TIMEOUT));
>+
>+	ieee80211_wake_queues(hw);
>+	WARN_ON(!ret);
> }
> 
> static const struct ieee80211_ops brcms_ops = {
>@@ -757,6 +777,7 @@ void brcms_dpc(unsigned long data)
> 
>  done:
> 	spin_unlock_bh(&wl->lock);
>+	wake_up(&wl->tx_flush_wq);
> }
> 
> /*
>@@ -1008,6 +1029,8 @@ static struct brcms_info *brcms_attach(struct bcma_device *pdev)
> 
> 	atomic_set(&wl->callbacks, 0);
> 
>+	init_waitqueue_head(&wl->tx_flush_wq);
>+
> 	/* setup the bottom half handler */
> 	tasklet_init(&wl->tasklet, brcms_dpc, (unsigned long) wl);
> 
>@@ -1591,13 +1614,3 @@ bool brcms_rfkill_set_hw_state(struct brcms_info *wl)
> 	spin_lock_bh(&wl->lock);
> 	return blocked;
> }
>-
>-/*
>- * precondition: perimeter lock has been acquired
>- */
>-void brcms_msleep(struct brcms_info *wl, uint ms)
>-{
>-	spin_unlock_bh(&wl->lock);
>-	msleep(ms);
>-	spin_lock_bh(&wl->lock);
>-}
>diff --git a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.h b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.h
>index 9358bd5..947ccac 100644
>--- a/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.h
>+++ b/drivers/net/wireless/brcm80211/brcmsmac/mac80211_if.h
>@@ -68,6 +68,8 @@ struct brcms_info {
> 	spinlock_t lock;	/* per-device perimeter lock */
> 	spinlock_t isr_lock;	/* per-device ISR synchronization lock */
> 
>+	/* tx flush */
>+	wait_queue_head_t tx_flush_wq;
> 
> 	/* timer related fields */
> 	atomic_t callbacks;	/* # outstanding callback functions */
>@@ -100,7 +102,6 @@ extern struct brcms_timer *brcms_init_timer(struct brcms_info *wl,
> extern void brcms_free_timer(struct brcms_timer *timer);
> extern void brcms_add_timer(struct brcms_timer *timer, uint ms, int periodic);
> extern bool brcms_del_timer(struct brcms_timer *timer);
>-extern void brcms_msleep(struct brcms_info *wl, uint ms);
> extern void brcms_dpc(unsigned long data);
> extern void brcms_timer(struct brcms_timer *t);
> extern void brcms_fatal_error(struct brcms_info *wl);
>diff --git a/drivers/net/wireless/brcm80211/brcmsmac/main.c b/drivers/net/wireless/brcm80211/brcmsmac/main.c
>index 03ca653..ee44126 100644
>--- a/drivers/net/wireless/brcm80211/brcmsmac/main.c
>+++ b/drivers/net/wireless/brcm80211/brcmsmac/main.c
>@@ -7979,23 +7979,14 @@ int brcms_c_get_curband(struct brcms_c_info *wlc)
> 	return wlc->band->bandunit;
> }
> 
>-void brcms_c_wait_for_tx_completion(struct brcms_c_info *wlc, bool drop)
>+void brcms_c_pktq_flush(struct brcms_c_info *wlc)
> {
>-	int timeout = 20;
>-
>-	/* flush packet queue when requested */
>-	if (drop)
>-		brcmu_pktq_flush(&wlc->pkt_queue->q, false, NULL, NULL);
>-
>-	/* wait for queue and DMA fifos to run dry */
>-	while (!pktq_empty(&wlc->pkt_queue->q) || brcms_txpktpendtot(wlc) > 0) {
>-		brcms_msleep(wlc->wl, 1);
>-
>-		if (--timeout == 0)
>-			break;
>-	}
>+	brcmu_pktq_flush(&wlc->pkt_queue->q, false, NULL, NULL);
>+}
> 
>-	WARN_ON_ONCE(timeout == 0);
>+bool brcms_c_tx_flush_completed(struct brcms_c_info *wlc)
>+{
>+	return pktq_empty(&wlc->pkt_queue->q) && !brcms_txpktpendtot(wlc);
> }
> 
> void brcms_c_set_beacon_listen_interval(struct brcms_c_info *wlc, u8 interval)
>diff --git a/drivers/net/wireless/brcm80211/brcmsmac/pub.h b/drivers/net/wireless/brcm80211/brcmsmac/pub.h
>index 5855f4f..59caa1c 100644
>--- a/drivers/net/wireless/brcm80211/brcmsmac/pub.h
>+++ b/drivers/net/wireless/brcm80211/brcmsmac/pub.h
>@@ -350,8 +350,6 @@ extern void brcms_c_associate_upd(struct brcms_c_info *wlc, bool state);
> extern void brcms_c_scan_start(struct brcms_c_info *wlc);
> extern void brcms_c_scan_stop(struct brcms_c_info *wlc);
> extern int brcms_c_get_curband(struct brcms_c_info *wlc);
>-extern void brcms_c_wait_for_tx_completion(struct brcms_c_info *wlc,
>-					   bool drop);
> extern int brcms_c_set_channel(struct brcms_c_info *wlc, u16 channel);
> extern int brcms_c_set_rate_limit(struct brcms_c_info *wlc, u16 srl, u16 lrl);
> extern void brcms_c_get_current_rateset(struct brcms_c_info *wlc,
>@@ -368,5 +366,7 @@ extern int brcms_c_set_tx_power(struct brcms_c_info *wlc, int txpwr);
> extern int brcms_c_get_tx_power(struct brcms_c_info *wlc);
> extern bool brcms_c_check_radio_disabled(struct brcms_c_info *wlc);
> extern void brcms_c_mute(struct brcms_c_info *wlc, bool on);
>+extern void brcms_c_pktq_flush(struct brcms_c_info *wlc);
>+extern bool brcms_c_tx_flush_completed(struct brcms_c_info *wlc);
> 
> #endif				/* _BRCM_PUB_H_ */
>-- 
>1.7.9.5
>

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Attachments on bug 787649: 559902 | 609744