[Gta04-owner] Small update to 3.7-gta04 kernel: faster wifi.

[Dr. H. Nikolaus Schaller]

Am 18.10.2013 um 13:17 schrieb NeilBrown:

> On Fri, 18 Oct 2013 12:00:57 +0200 "Dr. H. Nikolaus Schaller"
> <hns at goldelico.com> wrote:
> 
>> Hi Neil,
>> 
>> Am 18.10.2013 um 11:44 schrieb NeilBrown:
>> 
>>> 
>>> I've just pushed out a small update to 3.7-gta04.
>>> 
>>> This update adds support for the IRQ line from SDIO cards, such as the wifi
>>> in the gta04.
>>> This allows the wifi to go faster.
>>> With polling (the old behaviour) I get about 1Mb/sec
>>> With Interupts enabled and polling disabled I get about 4Mb/sec.
>>> If I have interrupts *and* polling (which admittedly is a strange
>>> config to even try) I get 5Mb/sec on my 800MHz board, and 6Mb/sec on
>>> my 1GHz board.
>> 
>> That is good news for Issue #488 [1].
>> 
>>> So the code currently does both.  It is a bit of a hack (and not the only
>>> hack) but it works OK for now.
>>> 
>>> This is will well short of the 40Mb/sec my notebook gets!
>>> So it is an improvement, but not as much as I had hoped.
>> 
>> Does you patch also work for 3.12 or does it need (additional) hacks?
>> 
>> Or has anyone already done speed tests with 3.12 showing if it is
>> really needed or not?
> 
> There is a 3.12 patch in my 'mainline' branch.
> 
> http://git.neil.brown.name/git?p=gta04.git;a=commitdiff;h=ad39271dc470f4c1ce048e58e4d137b37d5ff808
> 
> 
> There were patches on the omap list recently:
> https://lkml.org/lkml/2013/10/5/36
> 
> but they don't work for me.
> 
>> 
>> BTW: the MMC1 interface (SD card) is running with ca. 19 MByte/s
>> (which fits to the 25 MHz clock and 8 data bits parallel bus).
> 
> Isn't it a 4bit bus between the OMAP and the WIFI?

Yes, but that should still allow for ~ 9 MByte/s = 72 Mbit/s bandwidth.

So I wonder why we get the high data rate at the MMC1 interface
without IRQ patches, but not at MMC2 (with SDIO and Libertas).

BR,
Nikolaus