From 5368db4d7e0b65caf08929e5332d19d70186508a Mon Sep 17 00:00:00 2001 From: Bitterblue Smith Date: Sun, 8 Jan 2023 17:08:16 +0200 Subject: [PATCH] wifi: rtl8xxxu: Use a longer retry limit of 48 commit 2a86aa9a1892d60ef2e3f310f5b42b8b05546d65 upstream. The Realtek rate control algorithm goes back and forth a lot between the highest and the lowest rate it's allowed to use. This is due to a lot of frames being dropped because the retry limits set by IEEE80211_CONF_CHANGE_RETRY_LIMITS are too low. (Experimentally, they are 4 for long frames and 7 for short frames.) The vendor drivers hardcode the value 48 for both retry limits (for station mode), which makes dropped frames very rare and thus the rate control is more stable. Because most Realtek chips handle the rate control in the firmware, which can't be modified, ignore the limits set by IEEE80211_CONF_CHANGE_RETRY_LIMITS and use the value 48 (set during chip initialisation), same as the vendor drivers. Cc: stable@vger.kernel.org Signed-off-by: Bitterblue Smith Reviewed-by: Ping-Ke Shih Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/477d745b-6bac-111d-403c-487fc19aa30d@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c index 75d393b5dbe5e..d22990464dad6 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c @@ -5954,7 +5954,6 @@ static int rtl8xxxu_config(struct ieee80211_hw *hw, u32 changed) { struct rtl8xxxu_priv *priv = hw->priv; struct device *dev = &priv->udev->dev; - u16 val16; int ret = 0, channel; bool ht40; @@ -5964,14 +5963,6 @@ static int rtl8xxxu_config(struct ieee80211_hw *hw, u32 changed) __func__, hw->conf.chandef.chan->hw_value, changed, hw->conf.chandef.width); - if (changed & IEEE80211_CONF_CHANGE_RETRY_LIMITS) { - val16 = ((hw->conf.long_frame_max_tx_count << - RETRY_LIMIT_LONG_SHIFT) & RETRY_LIMIT_LONG_MASK) | - ((hw->conf.short_frame_max_tx_count << - RETRY_LIMIT_SHORT_SHIFT) & RETRY_LIMIT_SHORT_MASK); - rtl8xxxu_write16(priv, REG_RETRY_LIMIT, val16); - } - if (changed & IEEE80211_CONF_CHANGE_CHANNEL) { switch (hw->conf.chandef.width) { case NL80211_CHAN_WIDTH_20_NOHT: