From: Prasurjya Rohan Saikia <prasurjya.rohansaikia@xxxxxxxxxxxxx>
Added an algorithm to backoff the Tx Task when low memory scenario is
triggered at firmware. During high data transfer from host, the firmware
runs out of VMM memory, which is used to hold the frames from the host.
So added flow control to delay the transmit from host side when there is
not enough space to accomodate frames in firmware side.
Signed-off-by: Prasurjya Rohan Saikia <prasurjya.rohansaikia@xxxxxxxxxxxxx>
---
v1 -> v2: Removed the unused `timeout` variable.
v2 -> v3: Replaced schedule_timeout() by schedule_timeout_interruptible().
---
.../net/wireless/microchip/wilc1000/netdev.c | 21 +++++++++++++++----
.../net/wireless/microchip/wilc1000/netdev.h | 2 ++
2 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/microchip/wilc1000/netdev.c b/drivers/net/wireless/microchip/wilc1000/netdev.c
index e9f59de31b0b..f6bec17bfd0f 100644
--- a/drivers/net/wireless/microchip/wilc1000/netdev.c
+++ b/drivers/net/wireless/microchip/wilc1000/netdev.c
@@ -148,8 +148,8 @@ static int wilc_txq_task(void *vp)
complete(&wl->txq_thread_started);
while (1) {
- wait_for_completion(&wl->txq_event);
-
+ if (wait_for_completion_interruptible(&wl->txq_event))
+ continue;
if (wl->close) {
complete(&wl->txq_thread_started);
@@ -166,12 +166,25 @@ static int wilc_txq_task(void *vp)
srcu_idx = srcu_read_lock(&wl->srcu);
list_for_each_entry_rcu(ifc, &wl->vif_list,
list) {
- if (ifc->mac_opened && ifc->ndev)
+ if (ifc->mac_opened &&
+ netif_queue_stopped(ifc->ndev))
netif_wake_queue(ifc->ndev);
}
srcu_read_unlock(&wl->srcu, srcu_idx);
}
- } while (ret == WILC_VMM_ENTRY_FULL_RETRY && !wl->close);
+ if (ret != WILC_VMM_ENTRY_FULL_RETRY)
+ break;
+ /* Back off TX task from sending packets for some time.
+ * schedule_timeout_interruptible will allow RX task
+ * to run and free buffers. TX task will be in
+ * TASK_INTERRUPTIBLE state which will put the thread
+ * back to CPU running queue when it's signaled even
+ * if the timeout isn't elapsed. This gives faster chance
+ * for reserved SK buffers to be freed
+ */
+ schedule_timeout_interruptible(msecs_to_jiffies
+ (TX_BACKOFF_WEIGHT_MS));
+ } while (!wl->close);
}
return 0;
}
diff --git a/drivers/net/wireless/microchip/wilc1000/netdev.h b/drivers/net/wireless/microchip/wilc1000/netdev.h
index bb1a315a7b7e..aafe3dc44ac6 100644
--- a/drivers/net/wireless/microchip/wilc1000/netdev.h
+++ b/drivers/net/wireless/microchip/wilc1000/netdev.h
@@ -27,6 +27,8 @@
#define TCP_ACK_FILTER_LINK_SPEED_THRESH 54
#define DEFAULT_LINK_SPEED 72
+#define TX_BACKOFF_WEIGHT_MS 1
+
struct wilc_wfi_stats {
unsigned long rx_packets;
unsigned long tx_packets;
--
2.34.1
