From mboxrd@z Thu Jan 1 00:00:00 1970 From: Helmut Schaa Date: Sat, 21 Aug 2010 15:23:08 +0200 Subject: [ath9k-devel] About the video problem of ath9k_htc In-Reply-To: References: Message-ID: <201008211523.09127.helmut.schaa@googlemail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org Hi, Am Saturday 21 August 2010 schrieb LvEric: > I am using the ath9k_htc driver for TL -WN721N on my Linux Set top box. > > after insmod all moudles, plugin the TL-WN721N ,and run "wlist wlan0 scan", > > It can works,but the video output became sharking when scaning, when it finish the scaning, > > the video back to normal. why? This driver oprate some video output? Or something is same as the video driver? > > Any body known what is the reason of this? One possible explanation would be because the scanning involves changing the channel and as a result the wifi card cannot exchange data with the AP during that time (I just assume your set top box is configured as wireless STA and associates with an AP since otherwise you wouldn't need to scan). However, the software scan implementation in mac80211 uses the configured qos requiremenets to determine how many channels to scan at once. In order to reduce the average latency at the cost of a longer wireless scan duration you can use something like the attached python script (this will set the qos latency to 300ms while running, however not sure if the script is still up to date). This should advise mac80211 to not leave the operating channel for longer periods of time than 300ms (or by a different value you put in there). And one more thing: the scan implementation in mac80211 does not respect DTIM beacons at all and thus won't work nicely with mutli- and boradcast traffic at all. Not sure if that applies to your issue. HTH, Helmut -------------- next part -------------- A non-text attachment was scrubbed... Name: set_network_latency.py Type: text/x-python Size: 230 bytes Desc: not available Url : http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20100821/66818d15/attachment.py