* [PATCH] mt76: fix rx amsdu subframe processing
@ 2021-04-06 18:22 Felix Fietkau
2021-04-07 10:53 ` Lorenzo Bianconi
0 siblings, 1 reply; 2+ messages in thread
From: Felix Fietkau @ 2021-04-06 18:22 UTC (permalink / raw)
To: linux-wireless
When receiving an A-MSDU containing only a single subframe, status->last_amsdu
is set, but no previous head is present in the rx A-MSDU queue.
In this case, the A-MSDU subframe will be held until the next one is received,
potentially causing significant extra latency.
Fix this by releasing the frame instead of creating a new queue head if
last_amsdu is set.
Fixes: c7fd4a5d3f75 ("mt76: mt7915: enable hw rx-amsdu de-aggregation")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
drivers/net/wireless/mediatek/mt76/mac80211.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c
index 7684a8cf00fb..0d92b658b6a6 100644
--- a/drivers/net/wireless/mediatek/mt76/mac80211.c
+++ b/drivers/net/wireless/mediatek/mt76/mac80211.c
@@ -517,10 +517,14 @@ static void mt76_rx_release_burst(struct mt76_phy *phy, enum mt76_rxq_id q,
/* first amsdu subframe */
if (status->amsdu && !phy->rx_amsdu[q].head) {
+ if (status->last_amsdu) {
+ nskb = skb;
+ goto reset_burst;
+ }
phy->rx_amsdu[q].tail = &skb_shinfo(skb)->frag_list;
phy->rx_amsdu[q].seqno = status->seqno;
phy->rx_amsdu[q].head = skb;
- goto enqueue;
+ return;
}
/* ampdu or out-of-order amsdu subframes */
@@ -543,7 +547,6 @@ static void mt76_rx_release_burst(struct mt76_phy *phy, enum mt76_rxq_id q,
reset_burst:
phy->rx_amsdu[q].head = NULL;
phy->rx_amsdu[q].tail = NULL;
-enqueue:
if (nskb)
__skb_queue_tail(&dev->rx_skb[q], nskb);
}
--
2.30.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] mt76: fix rx amsdu subframe processing
2021-04-06 18:22 [PATCH] mt76: fix rx amsdu subframe processing Felix Fietkau
@ 2021-04-07 10:53 ` Lorenzo Bianconi
0 siblings, 0 replies; 2+ messages in thread
From: Lorenzo Bianconi @ 2021-04-07 10:53 UTC (permalink / raw)
To: Felix Fietkau; +Cc: linux-wireless
[-- Attachment #1: Type: text/plain, Size: 1742 bytes --]
> When receiving an A-MSDU containing only a single subframe, status->last_amsdu
> is set, but no previous head is present in the rx A-MSDU queue.
> In this case, the A-MSDU subframe will be held until the next one is received,
> potentially causing significant extra latency.
> Fix this by releasing the frame instead of creating a new queue head if
> last_amsdu is set.
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
>
> Fixes: c7fd4a5d3f75 ("mt76: mt7915: enable hw rx-amsdu de-aggregation")
> Signed-off-by: Felix Fietkau <nbd@nbd.name>
> ---
> drivers/net/wireless/mediatek/mt76/mac80211.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c
> index 7684a8cf00fb..0d92b658b6a6 100644
> --- a/drivers/net/wireless/mediatek/mt76/mac80211.c
> +++ b/drivers/net/wireless/mediatek/mt76/mac80211.c
> @@ -517,10 +517,14 @@ static void mt76_rx_release_burst(struct mt76_phy *phy, enum mt76_rxq_id q,
>
> /* first amsdu subframe */
> if (status->amsdu && !phy->rx_amsdu[q].head) {
> + if (status->last_amsdu) {
> + nskb = skb;
> + goto reset_burst;
> + }
> phy->rx_amsdu[q].tail = &skb_shinfo(skb)->frag_list;
> phy->rx_amsdu[q].seqno = status->seqno;
> phy->rx_amsdu[q].head = skb;
> - goto enqueue;
> + return;
> }
>
> /* ampdu or out-of-order amsdu subframes */
> @@ -543,7 +547,6 @@ static void mt76_rx_release_burst(struct mt76_phy *phy, enum mt76_rxq_id q,
> reset_burst:
> phy->rx_amsdu[q].head = NULL;
> phy->rx_amsdu[q].tail = NULL;
> -enqueue:
> if (nskb)
> __skb_queue_tail(&dev->rx_skb[q], nskb);
> }
> --
> 2.30.1
>
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2021-04-07 10:53 ` Lorenzo Bianconi
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