From f96b08a7e6f69c0f0a576554df3df5b1b519c479 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Tue, 17 Jan 2012 12:38:50 +0100 Subject: [PATCH 2/8] brcmsmac: fix tx queue flush infinite loop This patch workaround live deadlock problem caused by infinite loop in brcms_c_wait_for_tx_completion(). I do not consider the patch as the proper fix, which should fix the real reason of tx queue flush failure, but patch helps with system lockup. Reference: https://bugzilla.kernel.org/show_bug.cgi?id=42576 Reported-and-tested-by: Patrick Cc: stable@vger.kernel.org # 3.2+ Signed-off-by: Stanislaw Gruszka Signed-off-by: John W. Linville --- drivers/net/wireless/brcm80211/brcmsmac/main.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/drivers/net/wireless/brcm80211/brcmsmac/main.c b/drivers/net/wireless/brcm80211/brcmsmac/main.c index f7ed340..f6affc6 100644 --- a/drivers/net/wireless/brcm80211/brcmsmac/main.c +++ b/drivers/net/wireless/brcm80211/brcmsmac/main.c @@ -7981,13 +7981,21 @@ int brcms_c_get_curband(struct brcms_c_info *wlc) void brcms_c_wait_for_tx_completion(struct brcms_c_info *wlc, bool drop) { + 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) + while (!pktq_empty(&wlc->pkt_queue->q) || brcms_txpktpendtot(wlc) > 0) { brcms_msleep(wlc->wl, 1); + + if (--timeout == 0) + break; + } + + WARN_ON_ONCE(timeout == 0); } void brcms_c_set_beacon_listen_interval(struct brcms_c_info *wlc, u8 interval) -- 1.7.4.4