1 Introduction
Because the QCA scheme of WLAN has been responsible for product development, so there is no energy to go and get product MTK program. Nor is MTK program does not work, but it is really good, so there are too many companies, too many lives over many output product, personally think that devote their energies and resources to engage in MTK program, not market value. So, when a factory friends again and again to ask me for help to solve the WLAN ping packets lost, I always shirk are not familiar with the program. But his Jiabu Zhu grinding grumble, recently took some time to deal with this problem.
MTK's WLAN driver, and the new program is similar to QCA, the firmware is to be loaded onto the MCU. Benefit is that you do not understand that RF MCU, as long as the 802.11 upper-layer protocol can do; of course obvious shortcomings, you can not directly control the RF function through the registers. Even worse is that, not get documents, there is no express or implied code files full-featured set of registers and its specific position. Even the spread of the Internet programming class documentation, its role is quite limited, really informational purposes only, not solve the real problem.
2 DETAILED DESCRIPTION
Specific programs for hardware 7621A + 7603E + 7612E, did not EPA; but there PCIE slot and USB3.0 interface. After this I wish to engage in stable WLAN, use this hardware platform debugging 5G cellular modules to make a low-cost 5G equipment to use. After the official openwrt directly with the original package, compile the firmware uploaded to the device, found 5G still available, starting automatic frequency selection normal, will not seek death himself; but 2G is really too bad, boot the selected frequency is normal, However, with a bit difficult, various cards; big bag off of about 7% ping packet rate, and have the same grade QCA9531 light from several seconds.
First change the bandwidth, forced HT20 mode, BG protection release after the close TxBurst, tests showed little improvement.
Second change WME parameters to improve the rights of BE, several tests down a little improvement, at least not love parades around the circle when the Fantastic Art load.
Then followed by the release print ping package, found the PC ping packets sent, received and returned packet router, but the PC is off ping. BA Action existing adjustment processing logic, and different schemes for a card, the card found QCA scheme ping off only small number of packets.
Finally turned tmac, RMAC and rtmp_mac, andes_mt and GRP, continuously changing the configuration register, the driving parameter; found more interference scenario, TrainUpRuleRSSI will increase, in the TCR register tmac RDG_RA_MODE addition, other bits are set EN 1; the same time, the Retry frequency after modified by 0x17 0x0f, can significantly reduce the number of ping packets lost.
3 provisional results
Before without making adjustments in the office scene, daily 16:00 to 6:00 this day WLAN equipment performance the worst period of time (this period running stream QCA scheme of effect does not work, there is inexplicable interference), ping MTK program packet loss rate of more than 11%; however, after adjusting the code, the packet loss rate is not more than 1% a. ping 3000 packets, packet loss does not exceed 15. The other periods, very few encounter packet loss.
Of course, in order to solve the problem of packet loss, it appears that there is one or more registers to be adjusted, but do not know when to find the root cause of several upper registers or logic implementation point, can only continue to take the time to explore. Welcome all kinds of tips to do it as steady with QCA9531.