OpenSprinkler Forums Hardware Questions OpenSprinkler Beagle (OSBo) Edimax Nano, disconnects and packet loss with Ubuntu image Re: Re: Edimax Nano, disconnects and packet loss with Ubuntu ima



I also found the same problem with the driver. After sniffing from another pc running wireshark, it appeared that the aggregation sessions between the ap and the usb radio would deadlock. I tried running in non-ht mode and the problem disappeared. Next, I modified the driver to report no hardware aggregation support and the problem disappeared too. The latter allows you to run at ht speeds.

The problem seems to be that the AP starts an aggregation session and the STA starts one also before the AP session terminates. This seems to hang the driver.

I reported the problem to the linux-wireless list.

A patch is below. It’s not a fix, just a workaround until somebody more knowledgable has time to deal with it.


— a/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c
@@ -59,6 +59,9 @@ static int rtl92cu_init_sw_vars(struct ieee80211_hw *hw)
struct rtl_priv *rtlpriv = rtl_priv(hw);
int err;

+ /* disable aggregation until the deadlock is fixed */
+ hw->flags &= ~IEEE80211_HW_AMPDU_AGGREGATION;
rtlpriv->dm.dm_initialgain_enable = true;
rtlpriv->dm.dm_flag = 0;
rtlpriv->dm.disable_framebursting = false;