Kernel panic while using wireless (wifi) drivers of Mediatek 7601U chipset

After my experience with HP and theirs support team, I became much frustrated (Read it at http://wp.me/43Iof). Now I had few options left:

• Throw this garbage (HP Pavilion 15) to bin.
• Sell it on olx.
• Spend few more bucks and buy a wireless USB adapter.

Since, I found that a bug is opened for Mediatek 7630 PCIe card on launchpad, I assumed that the fix should be available with in few months. I dropped my idea of throwing it up. (Obviously, first two options were a ridiculous thought.)

Third option seems to be feasible. I bought ‘Leoxsys Nano Wireless N USB WiFi Adapter LEO-NANO150N’, which is based on Mediatek 7601U chipset (Actually, it was the cheapest one available on Internet. :D). I confirmed that drivers for Linux for the same chipset are available in market.

At that time, I was using Ubuntu 13.04 – 64 bit. I copy the driver (v 3.0.3) from provided CD, compiled and loaded the module. Nothing happened. Right, you heard me correct, nothing happened. Network Manager could not detect any wifi adapter. I installed wicd, and bla bla, but nothing worked.

After few days wasting, I found that you have to set following parameters in config.mk file.

‘HAS_WPA_SUPPLICANT=y’
‘HAS_NATIVE_WPA_SUPPLICANT_SUPPORT=y’

I dont know, why they did not set them by default. Whatever. I downloaded latest driver (v3.0.4) from Mediatek site, compiled and as soon as I inserted module, my wifi connection was alive. This is the first time, when my notebook was experiencing WIFI. If my notebook could have dance, it would have been dancing like Shakir. I had tears in my eyes due to happiness. lol…..

Soon after, I start downloading few required software. Within 5 minutes, kabooooooooooooooooooooooooooooooooooooom…. a black screen was displayed on screen. Everything was over. My notebook was feeling like Justin Bieber, completely screwed. I didn’t lost my whole faith in humanity. After hard boot, everything was working fine. Then after few minutes, system froze. Nothing was responding.

After, a lot of search, I found that the drives which Mediatek is providing is for 32 bit system. In 64 bit system, there are lot of changes required in 32 bit driver e.g. in 64 bit system, skb->tail is a pointer, in 32 bit system, it rather is an offset to add to skb->data to obtain the pointer.  The details description is provided at:

http://ubuntuforums.org/showthread.php?t=2092888

http://pastebin.com/VkUjULJ5

I discussed the same with Mediatek team and they agreed that this is the reason of Kernel Panic.

Following is the mail communication received from Mediatek team;

“Great thanks for your detail information. It really a issue of the 64-bit system.  Did you try patches described in these websites? If so, did the kernel still crash?”

The above answered was received on 28-Oct-2013. Since then, I have not listen from the team. Neither there is any new version uploaded on Mediatek site.

I have now shifted to Mint 15 – 32 bit system. Now everything is working fine. My life just became hell  due to HP and Mediatek. Now, I am able to run wifi with USB dongle. Neither HP nor Mediatek has provided any drivers for 7630 card till now (28-Nov-13). In fact Mediatek has not provided a single reply for all the mails sent for 7630 card.

I hope soon I will be using inbuilt wifi card. With this hope, I finish this post here.