b94177e10f
The radio would stop communicating completely. This issue was easiest to trigger on AR913x devices, e.g. the TP-Link TL-WR1043ND, but other hardware was occasionally affected as well. The most critical issue was a race condition in disabling/enabling IRQs between the IRQ handler and the IRQ processing tasklet Signed-off-by: Felix Fietkau <nbd@nbd.name>
100 lines
3 KiB
Diff
100 lines
3 KiB
Diff
From: Felix Fietkau <nbd@nbd.name>
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Date: Wed, 25 Jan 2017 13:00:58 +0100
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Subject: [PATCH] ath9k: check for deaf rx path state
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Various chips occasionally run into a state where the tx path still
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appears to be working normally, but the rx path is deaf.
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There is no known register signature to check for this state explicitly,
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so use the lack of rx interrupts as an indicator.
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This detection is prone to false positives, since a device could also
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simply be in an environment where there are no frames on the air.
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However, in this case doing a reset should be harmless since it's
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obviously not interrupting any real activity. To avoid confusion, call
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the reset counters in this case "Rx path inactive" instead of something
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like "Rx path deaf", since it may not be an indication of a real
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hardware failure.
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Signed-off-by: Felix Fietkau <nbd@nbd.name>
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---
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--- a/drivers/net/wireless/ath/ath9k/ath9k.h
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+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
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@@ -1027,6 +1027,7 @@ struct ath_softc {
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u8 gtt_cnt;
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u32 intrstatus;
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+ u32 rx_active;
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u16 ps_flags; /* PS_* */
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bool ps_enabled;
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bool ps_idle;
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--- a/drivers/net/wireless/ath/ath9k/debug.c
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+++ b/drivers/net/wireless/ath/ath9k/debug.c
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@@ -763,6 +763,7 @@ static int read_file_reset(struct seq_fi
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[RESET_TYPE_BEACON_STUCK] = "Stuck Beacon",
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[RESET_TYPE_MCI] = "MCI Reset",
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[RESET_TYPE_CALIBRATION] = "Calibration error",
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+ [RESET_TYPE_RX_INACTIVE] = "Rx path inactive",
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[RESET_TX_DMA_ERROR] = "Tx DMA stop error",
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[RESET_RX_DMA_ERROR] = "Rx DMA stop error",
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};
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--- a/drivers/net/wireless/ath/ath9k/debug.h
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+++ b/drivers/net/wireless/ath/ath9k/debug.h
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@@ -50,6 +50,7 @@ enum ath_reset_type {
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RESET_TYPE_BEACON_STUCK,
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RESET_TYPE_MCI,
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RESET_TYPE_CALIBRATION,
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+ RESET_TYPE_RX_INACTIVE,
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RESET_TX_DMA_ERROR,
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RESET_RX_DMA_ERROR,
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__RESET_TYPE_MAX
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--- a/drivers/net/wireless/ath/ath9k/link.c
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+++ b/drivers/net/wireless/ath/ath9k/link.c
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@@ -53,13 +53,27 @@ reset:
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}
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+static bool ath_rx_active_check(struct ath_softc *sc)
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+{
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+ if (sc->rx_active) {
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+ sc->rx_active = 0;
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+ return true;
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+ }
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+
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+ ath_dbg(ath9k_hw_common(sc->sc_ah), RESET,
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+ "rx path inactive, resetting the chip\n");
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+ ath9k_queue_reset(sc, RESET_TYPE_RX_INACTIVE);
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+ return false;
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+}
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+
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void ath_hw_check_work(struct work_struct *work)
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{
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struct ath_softc *sc = container_of(work, struct ath_softc,
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hw_check_work.work);
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if (!ath_hw_check(sc) ||
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- !ath_tx_complete_check(sc))
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+ !ath_tx_complete_check(sc) ||
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+ !ath_rx_active_check(sc))
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return;
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ieee80211_queue_delayed_work(sc->hw, &sc->hw_check_work,
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--- a/drivers/net/wireless/ath/ath9k/main.c
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+++ b/drivers/net/wireless/ath/ath9k/main.c
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@@ -269,6 +269,7 @@ static bool ath_complete_reset(struct at
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}
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sc->gtt_cnt = 0;
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+ sc->rx_active = 1;
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ath9k_hw_set_interrupts(ah);
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ath9k_hw_enable_interrupts(ah);
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@@ -452,6 +453,7 @@ void ath9k_tasklet(unsigned long data)
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ath_rx_tasklet(sc, 0, true);
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ath_rx_tasklet(sc, 0, false);
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+ sc->rx_active = 1;
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}
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if (status & ATH9K_INT_TX) {
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