97 lines
3.5 KiB
Diff
97 lines
3.5 KiB
Diff
From: Sergey Ryazanov <ryazanov.s.a@gmail.com>
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Date: Wed, 4 Mar 2015 05:12:11 +0300
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Subject: [PATCH] ath5k: fix reset race
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To prepare for reset ath5k should finish all asynchronous tasks. At
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first, it disables the interrupt generation, then it waits for the
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interrupt handler and tasklets completion, and then proceeds to the HW
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configuration update. But it does not consider that the interrupt
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handler or tasklet re-enables the interrupt generation. And we fall in a
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situation when ath5k assumes that interrupts are disabled, but it is
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not.
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This can lead to different consequences, such as reception of the frame,
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when we do not expect it. Under certain circumstances, this can lead to
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the following warning:
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WARNING: at ath5k/base.c:589 ath5k_tasklet_rx+0x318/0x6ec [ath5k]()
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invalid hw_rix: 1a
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[..]
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Call Trace:
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[<802656a8>] show_stack+0x48/0x70
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[<802dd92c>] warn_slowpath_common+0x88/0xbc
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[<802dd98c>] warn_slowpath_fmt+0x2c/0x38
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[<81b51be8>] ath5k_tasklet_rx+0x318/0x6ec [ath5k]
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[<8028ac64>] tasklet_action+0x8c/0xf0
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[<80075804>] __do_softirq+0x180/0x32c
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[<80196ce8>] irq_exit+0x54/0x70
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[<80041848>] ret_from_irq+0x0/0x4
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[<80182fdc>] ioread32+0x4/0xc
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[<81b4c42c>] ath5k_hw_set_sleep_clock+0x2ec/0x474 [ath5k]
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[<81b4cf28>] ath5k_hw_reset+0x50/0xeb8 [ath5k]
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[<81b50900>] ath5k_reset+0xd4/0x310 [ath5k]
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[<81b557e8>] ath5k_config+0x4c/0x104 [ath5k]
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[<80d01770>] ieee80211_hw_config+0x2f4/0x35c [mac80211]
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[<80d09aa8>] ieee80211_scan_work+0x2e4/0x414 [mac80211]
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[<8022c3f4>] process_one_work+0x28c/0x400
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[<802df8f8>] worker_thread+0x258/0x3c0
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[<801b5710>] kthread+0xe0/0xec
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[<800418a8>] ret_from_kernel_thread+0x14/0x1c
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Fix this issue by adding a new status flag, which forbids to re-enable
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the interrupt generation until the HW configuration is completed.
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Note: previous patch, which reorders the Rx disable code helps to avoid
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the above warning, but not fixes the root cause of unexpected frame
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receiving.
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CC: Jiri Slaby <jirislaby@gmail.com>
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CC: Nick Kossifidis <mickflemm@gmail.com>
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CC: Luis R. Rodriguez <mcgrof@do-not-panic.com>
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Reported-by: Christophe Prevotaux <cprevotaux@nltinc.com>
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Tested-by: Christophe Prevotaux <cprevotaux@nltinc.com>
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Tested-by: Eric Bree <ebree@nltinc.com>
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Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
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---
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--- a/drivers/net/wireless/ath/ath5k/ath5k.h
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+++ b/drivers/net/wireless/ath/ath5k/ath5k.h
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@@ -1283,6 +1283,7 @@ struct ath5k_hw {
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#define ATH_STAT_PROMISC 1
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#define ATH_STAT_LEDSOFT 2 /* enable LED gpio status */
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#define ATH_STAT_STARTED 3 /* opened & irqs enabled */
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+#define ATH_STAT_RESET 4 /* hw reset */
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unsigned int filter_flags; /* HW flags, AR5K_RX_FILTER_* */
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unsigned int fif_filter_flags; /* Current FIF_* filter flags */
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--- a/drivers/net/wireless/ath/ath5k/base.c
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+++ b/drivers/net/wireless/ath/ath5k/base.c
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@@ -1523,6 +1523,9 @@ ath5k_set_current_imask(struct ath5k_hw
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enum ath5k_int imask;
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unsigned long flags;
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+ if (test_bit(ATH_STAT_RESET, ah->status))
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+ return;
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+
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spin_lock_irqsave(&ah->irqlock, flags);
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imask = ah->imask;
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if (ah->rx_pending)
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@@ -2862,6 +2865,8 @@ ath5k_reset(struct ath5k_hw *ah, struct
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ATH5K_DBG(ah, ATH5K_DEBUG_RESET, "resetting\n");
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+ __set_bit(ATH_STAT_RESET, ah->status);
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+
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ath5k_hw_set_imr(ah, 0);
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synchronize_irq(ah->irq);
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ath5k_stop_tasklets(ah);
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@@ -2952,6 +2957,8 @@ ath5k_reset(struct ath5k_hw *ah, struct
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*/
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/* ath5k_chan_change(ah, c); */
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+ __clear_bit(ATH_STAT_RESET, ah->status);
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+
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ath5k_beacon_config(ah);
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/* intrs are enabled by ath5k_beacon_config */
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