wl1271: Improvements to the TX path
- Fix a TX result overflow problem that was present in the TX path and visible
with at least linksys AP's (probably any AP with high throughput capability.)
- Optimize TX by writing FW trigger for a group of TX frames instead of
each and every frame.
- Slightly optimize the TX path code.
Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/wl12xx/wl1271_tx.c b/drivers/net/wireless/wl12xx/wl1271_tx.c
index 2b7dd9b..2e057b0 100644
--- a/drivers/net/wireless/wl12xx/wl1271_tx.c
+++ b/drivers/net/wireless/wl12xx/wl1271_tx.c
@@ -169,7 +169,6 @@
/* write packet new counter into the write access register */
wl->tx_packets_count++;
- wl1271_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
desc = (struct wl1271_tx_hw_descr *) skb->data;
wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
@@ -244,6 +243,7 @@
struct sk_buff *skb;
bool woken_up = false;
u32 sta_rates = 0;
+ u32 prev_tx_packets_count;
int ret;
/* check if the rates supported by the AP have changed */
@@ -260,6 +260,8 @@
if (unlikely(wl->state == WL1271_STATE_OFF))
goto out;
+ prev_tx_packets_count = wl->tx_packets_count;
+
/* if rates have changed, re-configure the rate policy */
if (unlikely(sta_rates)) {
wl->rate_set = wl1271_tx_enabled_rates_get(wl, sta_rates);
@@ -270,7 +272,7 @@
if (!woken_up) {
ret = wl1271_ps_elp_wakeup(wl, false);
if (ret < 0)
- goto out;
+ goto out_ack;
woken_up = true;
}
@@ -282,10 +284,10 @@
ieee80211_stop_queues(wl->hw);
set_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags);
skb_queue_head(&wl->tx_queue, skb);
- goto out;
+ goto out_ack;
} else if (ret < 0) {
dev_kfree_skb(skb);
- goto out;
+ goto out_ack;
} else if (test_and_clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED,
&wl->flags)) {
/* firmware buffer has space, restart queues */
@@ -295,6 +297,11 @@
}
}
+out_ack:
+ /* interrupt the firmware with the new packets */
+ if (prev_tx_packets_count != wl->tx_packets_count)
+ wl1271_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
+
out:
if (woken_up)
wl1271_ps_elp_sleep(wl);
@@ -311,7 +318,7 @@
int id = result->id;
/* check for id legality */
- if (id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL) {
+ if (unlikely(id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL)) {
wl1271_warning("TX result illegal id: %d", id);
return;
}
@@ -366,10 +373,11 @@
}
/* Called upon reception of a TX complete interrupt */
-void wl1271_tx_complete(struct wl1271 *wl, u32 count)
+void wl1271_tx_complete(struct wl1271 *wl)
{
struct wl1271_acx_mem_map *memmap =
(struct wl1271_acx_mem_map *)wl->target_mem_map;
+ u32 count, fw_counter;
u32 i;
wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);
@@ -377,12 +385,18 @@
/* read the tx results from the chipset */
wl1271_read(wl, le32_to_cpu(memmap->tx_result),
wl->tx_res_if, sizeof(*wl->tx_res_if), false);
+ fw_counter = le32_to_cpu(wl->tx_res_if->tx_result_fw_counter);
+
+ /* write host counter to chipset (to ack) */
+ wl1271_write32(wl, le32_to_cpu(memmap->tx_result) +
+ offsetof(struct wl1271_tx_hw_res_if,
+ tx_result_host_counter), fw_counter);
+
+ count = fw_counter - wl->tx_results_count;
/* verify that the result buffer is not getting overrun */
- if (count > TX_HW_RESULT_QUEUE_LEN) {
+ if (unlikely(count > TX_HW_RESULT_QUEUE_LEN))
wl1271_warning("TX result overflow from chipset: %d", count);
- count = TX_HW_RESULT_QUEUE_LEN;
- }
/* process the results */
for (i = 0; i < count; i++) {
@@ -395,12 +409,6 @@
wl->tx_results_count++;
}
-
- /* write host counter to chipset (to ack) */
- wl1271_write32(wl, le32_to_cpu(memmap->tx_result) +
- offsetof(struct wl1271_tx_hw_res_if,
- tx_result_host_counter),
- le32_to_cpu(wl->tx_res_if->tx_result_fw_counter));
}
/* caller must hold wl->mutex */