After fixing mac80211 to allow larger A-MSDUs in some cases, there have been
reports of performance regressions and packet loss with some clients.
It appears that the issue occurs when the hardware is transmitting A-MSDUs
bigger than 8k. Limit the local VHT MPDU size capability to 7991, matching
the value used for MT7915 as well.
Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/mediatek/mt76/mt7615/init.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/init.c b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
index 2a4db46727fb..e194259c84e9 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
@@ -481,7 +481,7 @@ void mt7615_init_device(struct mt7615_dev *dev)
dev->mphy.sband_2g.sband.ht_cap.cap |= IEEE80211_HT_CAP_LDPC_CODING;
dev->mphy.sband_5g.sband.ht_cap.cap |= IEEE80211_HT_CAP_LDPC_CODING;
dev->mphy.sband_5g.sband.vht_cap.cap |=
- IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454 |
+ IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_7991 |
IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
mt7615_cap_dbdc_disable(dev);
dev->phy.dfs_state = -1;
--
2.28.0
Felix Fietkau <[email protected]> writes:
> After fixing mac80211 to allow larger A-MSDUs in some cases, there have been
> reports of performance regressions and packet loss with some clients.
> It appears that the issue occurs when the hardware is transmitting A-MSDUs
> bigger than 8k. Limit the local VHT MPDU size capability to 7991, matching
> the value used for MT7915 as well.
>
> Signed-off-by: Felix Fietkau <[email protected]>
I'm planning to queue this to v5.9 and I assigned the patch to me in
patchwork.
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Felix Fietkau <[email protected]> wrote:
> After fixing mac80211 to allow larger A-MSDUs in some cases, there have been
> reports of performance regressions and packet loss with some clients.
> It appears that the issue occurs when the hardware is transmitting A-MSDUs
> bigger than 8k. Limit the local VHT MPDU size capability to 7991, matching
> the value used for MT7915 as well.
>
> Signed-off-by: Felix Fietkau <[email protected]>
Patch applied to wireless-drivers.git, thanks.
efb1676306f6 mt76: mt7615: reduce maximum VHT MPDU length to 7991
--
https://patchwork.kernel.org/patch/11793855/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches