From: Shrenik Shikhare <shrenik@xxxxxxxxxxx>
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 <cluo@xxxxxxxxxxx>
Signed-off-by: Ganapathi Bhat <gbhat@xxxxxxxxxxx>
---
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
