Return-path: Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]:51734 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750851AbeAYKTI (ORCPT ); Thu, 25 Jan 2018 05:19:08 -0500 From: Ganapathi Bhat To: CC: Brian Norris , Cathy Luo , Xinming Hu , Zhiyuan Yang , James Cao , Mangesh Malusare , Shrenik Shikhare , Ganapathi Bhat Subject: [PATCH v2 1/2] mwifiex: schedule rx_work on RX interrupt for USB Date: Thu, 25 Jan 2018 15:44:35 +0530 Message-ID: <1516875276-12171-2-git-send-email-gbhat@marvell.com> (sfid-20180125_111913_792961_DCAB4F4A) In-Reply-To: <1516875276-12171-1-git-send-email-gbhat@marvell.com> References: <1516875276-12171-1-git-send-email-gbhat@marvell.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Shrenik Shikhare There is race for data_received flag between main thread and RX data interrupt(mwifiex_usb_rx_complete()): 1. USB received an RX data interrupt, set data_received flag 2. main thread checks data_received, if set queues rx_work 3. rx worker thread independently start processing rx_data_q 4. rx work exits (once rx_data_q is empty) 5. main thread resets the data_received flag(after #2) 6. Now at the corner case there will be high RX data interrupts between #4 and #5 7. Driver stops submitting URBs to firmware, once rx_pending exceeds HIGH_RX_PENDING 8. The flag data_received(cleared in #5) will remain unset since there will be no interrupts from firmware to set it(after #7) Above scenario causes RX stall in driver, which will finally result in command/TX timeouts in firmware. As a fix, queue rx_work directly in mwifiex_usb_rx_complete() callback, instead in the main thread. This removes dependency of RX processing on data_received flag. Signed-off-by: Cathy Luo Signed-off-by: Ganapathi Bhat --- v2: same as v1 --- drivers/net/wireless/marvell/mwifiex/main.c | 7 ++++--- drivers/net/wireless/marvell/mwifiex/main.h | 1 + drivers/net/wireless/marvell/mwifiex/usb.c | 2 ++ 3 files changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/marvell/mwifiex/main.c b/drivers/net/wireless/marvell/mwifiex/main.c index 12e7399..6e6e1a7 100644 --- a/drivers/net/wireless/marvell/mwifiex/main.c +++ b/drivers/net/wireless/marvell/mwifiex/main.c @@ -171,7 +171,7 @@ void mwifiex_queue_main_work(struct mwifiex_adapter *adapter) } EXPORT_SYMBOL_GPL(mwifiex_queue_main_work); -static void mwifiex_queue_rx_work(struct mwifiex_adapter *adapter) +void mwifiex_queue_rx_work(struct mwifiex_adapter *adapter) { unsigned long flags; @@ -183,6 +183,7 @@ static void mwifiex_queue_rx_work(struct mwifiex_adapter *adapter) queue_work(adapter->rx_workqueue, &adapter->rx_work); } } +EXPORT_SYMBOL_GPL(mwifiex_queue_rx_work); static int mwifiex_process_rx(struct mwifiex_adapter *adapter) { @@ -283,10 +284,10 @@ int mwifiex_main_process(struct mwifiex_adapter *adapter) mwifiex_process_hs_config(adapter); if (adapter->if_ops.process_int_status) adapter->if_ops.process_int_status(adapter); + if (adapter->rx_work_enabled && adapter->data_received) + mwifiex_queue_rx_work(adapter); } - if (adapter->rx_work_enabled && adapter->data_received) - mwifiex_queue_rx_work(adapter); /* Need to wake up the card ? */ if ((adapter->ps_state == PS_STATE_SLEEP) && diff --git a/drivers/net/wireless/marvell/mwifiex/main.h b/drivers/net/wireless/marvell/mwifiex/main.h index 6b5539b..66ba95c 100644 --- a/drivers/net/wireless/marvell/mwifiex/main.h +++ b/drivers/net/wireless/marvell/mwifiex/main.h @@ -1667,6 +1667,7 @@ u8 mwifiex_adjust_data_rate(struct mwifiex_private *priv, void mwifiex_upload_device_dump(struct mwifiex_adapter *adapter); void *mwifiex_alloc_dma_align_buf(int rx_len, gfp_t flags); void mwifiex_queue_main_work(struct mwifiex_adapter *adapter); +void mwifiex_queue_rx_work(struct mwifiex_adapter *adapter); int mwifiex_get_wakeup_reason(struct mwifiex_private *priv, u16 action, int cmd_type, struct mwifiex_ds_wakeup_reason *wakeup_reason); diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c index 4bc2448..d20fda1 100644 --- a/drivers/net/wireless/marvell/mwifiex/usb.c +++ b/drivers/net/wireless/marvell/mwifiex/usb.c @@ -144,6 +144,8 @@ static int mwifiex_usb_recv(struct mwifiex_adapter *adapter, skb_queue_tail(&adapter->rx_data_q, skb); adapter->data_received = true; atomic_inc(&adapter->rx_pending); + if (adapter->rx_work_enabled) + mwifiex_queue_rx_work(adapter); break; default: mwifiex_dbg(adapter, ERROR, -- 1.9.1