Letux Kernel

Issue 488: WiFi speed

Reported by Nikolaus Schaller, Oct 16, 2013

there has been a report that WiFi speed is low. This appears to be 
related to SDIO interrupt handling and was apparently improved in 
the 2.6.32 kernel by this patch:


Comment 1 by Nikolaus Schaller, Oct 19, 2013

There was also a report/patch for 3.5-rc2:


I was under the impression that it was included in 3.7 and therefore 
in our 3.12-rc5.

Comment 2 by Nikolaus Schaller, Dec 15, 2013

What is the influence (if at all) of the different WiFi firmware 
variants we can install through Debian nonfree? 

There are different variants:

-rw-r--r-- 1 root root 122800 Jan  6  2013 
-rw-r--r-- 1 root root   2464 Jan  6  2013 
-rw-r--r-- 1 root root 124188 Jan  6  2013 
-rw-r--r-- 1 root root   2516 Jan  6  2013 
-rw-r--r-- 1 root root 122916 Feb 29  2008 /lib/firmware/sd8686.bin
-rw-r--r-- 1 root root   2516 May 12  2009 

Or maybe we are patching an old firmware over the latest Debian 


Comment 3 by Nikolaus Schaller, Dec 15, 2013

After reinstaling firmware-libertas we have

root@gta04:~# ls -l /lib/firmware/sd8686*
lrwxrwxrwx 1 root root 22 Jan  6  2013 /lib/firmware/sd8686.bin 
-> libertas/sd8686_v8.bin
lrwxrwxrwx 1 root root 29 Jan  6  2013 
/lib/firmware/sd8686_helper.bin -> libertas/sd8686_v8_helper.bin

I.e. we indeed have a newer version than the patch. And it is v8 but 
still not yet v9.

Comment 4 by Lukas M, Jun 28, 2014

In the 3.12-replicant kernel, the following commit improved wifi 
speed by a factor of 4 (according to PaulK):


Comment 5 by Nikolaus Schaller, Jun 28, 2014

Looks nice if he has made it 3.12 compatible.

A problem might be that none of us understands it and can upstream 
it :(

And we have to check if 3.16 and DT did not do something similar 
(SDIO with interrupts). I remember that there is some DT option to 
define if the SDIO interface should support IRQ or not. But I am not 

Comment 6 by Nikolaus Schaller, Jan 8, 2017

Is this still an issue?

Comment 7 by Andreas Kemnade, Jan 8, 2017

the mentioned stuff is in our feature branches, so it is solved in 
our tree,

but cleaning it up for upstream still needs to be done

Created: 10 years 8 months ago by Nikolaus Schaller

Updated: 7 years 5 months ago

Status: New

Followed by: 2 persons