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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Johannes Berg <johannes.berg@intel.com>,
        Luca Coelho <luciano.coelho@intel.com>,
        Kalle Valo <kvalo@codeaurora.org>
Subject: [PATCH 5.4 128/168] iwlwifi: pcie: actually release queue memory in TVQM
Date:   Tue, 28 Apr 2020 20:25:02 +0200
Message-Id: <20200428182248.371321557@linuxfoundation.org>
In-Reply-To: <20200428182231.704304409@linuxfoundation.org>
References: <20200428182231.704304409@linuxfoundation.org>
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From: Johannes Berg <johannes.berg@intel.com>

commit b98b33d5560a2d940f3b80f6768a6177bf3dfbc0 upstream.

The iwl_trans_pcie_dyn_txq_free() function only releases the frames
that may be left on the queue by calling iwl_pcie_gen2_txq_unmap(),
but doesn't actually free the DMA ring or byte-count tables for the
queue. This leads to pretty large memory leaks (at least before my
queue size improvements), in particular in monitor/sniffer mode on
channel hopping since this happens on every channel change.

This was also now more evident after the move to a DMA pool for the
byte count tables, showing messages such as

  BUG iwlwifi:bc (...): Objects remaining in iwlwifi:bc on __kmem_cache_shutdown()

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=206811.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Fixes: 6b35ff91572f ("iwlwifi: pcie: introduce a000 TX queues management")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20200417100405.f5f4c4193ec1.Id5feebc9b4318041913a9c89fc1378bb5454292c@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
@@ -1283,6 +1283,9 @@ void iwl_trans_pcie_dyn_txq_free(struct
 
 	iwl_pcie_gen2_txq_unmap(trans, queue);
 
+	iwl_pcie_gen2_txq_free_memory(trans, trans_pcie->txq[queue]);
+	trans_pcie->txq[queue] = NULL;
+
 	IWL_DEBUG_TX_QUEUES(trans, "Deactivate queue %d\n", queue);
 }