Re: [ath9k-devel] AR9287 ; 2-wire coexistence expected behavior

[Adrian Chadd <adrian@freebsd.org>]

hi,

I'd first double-check that you've correctly configured the btactive
GPIO pin to be an input and the mux config makes it be BT_ACTIVE.

I can't really help you more than this right now; I haven't sat down
and actually tried this. :-(

But it doesn't look like much else needs to happen besides configuring
the GPIOs right, enabling BTCOEX and setting the weights.

Thanks,


Adrian

On 7 April 2013 22:20, sandeep suresh <sandeep.suresh@yahoo.co.in> wrote:
> Hello Mr.Adrian & Mr.Sujith,
>     Started doing some experiments with different settings but there wasn't
> any good progress. Need your help further in analysis & recommendation,
> please. I monitor WLAN_ACTIVE (GPIO5) and BT_ACTIVE (GPIO6) on the
> oscilloscope. There were always a lot of pulse trains on WLAN_ACTIVE. On
> BT_ACTIVE, I initially pulled it high and also tested with a periodic pulse
> train (450ms On and 450ms Off). The following were the different settings
> with which I tested; the difference across each test case is marked in
> underline/bold:
>
> 1. In ath9k_hw_btcoex_enable_2wire(), I added the following code:
>     ath9k_hw_btcoex_set_weight(ah, AR_BT_COEX_WGHT, AR_STOMP_LOW_WLAN_WGHT);
>     REG_WRITE(ah, AR_BT_COEX_WEIGHT, btcoex_hw->bt_coex_weights);
>     Result: WLAN_ACTIVE pulse trains observed during BT_ACTIVE high.
>
> 2. In ath9k_hw_btcoex_enable_2wire(), I added the following code:
>     ath9k_hw_btcoex_set_weight(ah, AR_BT_COEX_WGHT, AR_STOMP_ALL_WLAN_WGHT);
>     REG_WRITE(ah, AR_BT_COEX_WEIGHT, btcoex_hw->bt_coex_weights);
>     Result: WLAN_ACTIVE pulse trains observed during BT_ACTIVE high.
>
> 3. In ath9k_hw_btcoex_enable_2wire(), I added the following code:
>     ath9k_hw_btcoex_set_weight(ah, 0xFFFF, 0x0000);
>     REG_WRITE(ah, AR_BT_COEX_WEIGHT, btcoex_hw->bt_coex_weights);
>     Result: WLAN_ACTIVE pulse trains observed during BT_ACTIVE high.
>
> In the next test cases, I realized that there are two registers
> (AR_BT_COEX_MODE, AR_BT_COEX_MODE2) for setting the coexistence mode. The
> following is the code and the test results:
>
> 4. In ath9k_hw_btcoex_enable_2wire(), I added the following code:
>     REG_WRITE(ah, AR_BT_COEX_MODE, btcoex_hw->bt_coex_mode);
>     REG_WRITE(ah, AR_BT_COEX_MODE2, btcoex_hw->bt_coex_mode);
>     ath9k_hw_btcoex_set_weight(ah, AR_BT_COEX_WGHT, AR_STOMP_LOW_WLAN_WGHT);
>     REG_WRITE(ah, AR_BT_COEX_WEIGHT, btcoex_hw->bt_coex_weights);
>     Result: WLAN_ACTIVE pulse trains observed during BT_ACTIVE high.
>
>
>     Result: WLAN_ACTIVE pulse trains observed during BT_ACTIVE high.
>
> 5.    Next I changed different enum for BT coex modes i.e ath_bt_mode.
> Changed from ATH_BT_COEX_MODE_SLOTTED, ATH_BT_COEX_MODE_UNSLOTTED and
> ATH_BT_COEX_MODE_LEGACY. I used again the above settings. But there still
> there were pulse trains observed.
>
> Please help to further solve these problems, please.
> Regards
> Sandeep Suresh.
> From: Adrian Chadd <adrian@freebsd.org>
> To: sandeep suresh <sandeep.suresh@yahoo.co.in>
> Cc: Sujith Manoharan <sujith@msujith.org>; ath9k-devel
> <ath9k-devel@lists.ath9k.org>; "linux-wireless@vger.kernel.org"
> <linux-wireless@vger.kernel.org>
> Sent: Sunday, 7 April 2013 11:16 PM
>
> Subject: Re: [ath9k-devel] AR9287 ; 2-wire coexistence expected behavior
>
> On 7 April 2013 07:54, sandeep suresh <sandeep.suresh@yahoo.co.in> wrote:
>> Hello Mr.Adrian and Mr.Sujith,
>>    Thanks for your responses. In order to ensure that all of us are on the
>> same page and referring to the same code base, some queries:
>>
>> 1. Please let me know you are referring to freebsd.org or
>> linuxwireless.org
>> drivers? Because you are referring to Kite & Kiwi which are in FreeBSD.
>>    FreeBSD --> http://svn.freebsd.org/base/head/sys/
>>    Ath9k --> http://linuxwireless.org/en/users/Drivers/ath9k
>>    Because currently I am using ath9k drivers only from linuxwireless.org.
>
> Kite = AR9285
> Kiwi = AR9287
>
> I know ath9k enough to be (somewhat) helpful and dangerous. But I'm
> the FreeBSD guy here; I know the HAL and FreeBSD code much better.
>
> The FreeBSD code is closer to what our reference driver does / did
> than Linux, at least for the legacy chipset support.
>
>> 2. Which version of ath9k driver is stable & complete from 2-wire/3-wire
>> coexistence? The reason for this query is that I downloaded
>> compat-wireless-3.6.8-1 which contains the function ath9k_start_btcoex()
>> in
>> which the Weight register is initialized. But this function is not
>> available
>> in some of the stable versions of ath9k which I am using.
>
> Not unsurprising. ath9k's btcoex code is (relatively) recent. it
> sounds like you've been using an older kernel.
>
>> 3. What exactly are Kite and Kiwi? Are these third party modules using
>> AR9287 Atheros chipsets? I did not see this in linuxwireless.org but only
>> in
>> FreeBSD.
>
> They're chip names. AR9285 = Kite, AR9287 = Kiwi.
>
>> 4. Just wanted to confirm if the address of the weight register that you
>> are
>> mentioning below for 2-wire coexistence is : AR_BT_COEX_WEIGHT (0x8174)
>
> Yup. That's what it is for AR5146 -> AR9287. AR9380 changed this.
>
>> 5. Just wanted to cross check if the weight register mentioned is for
>> 2-wire
>> coexistence? The reason for this doubt is I see bt_freq, bt_prio bits
>>    in BT weight register and these bits are relevant to BT_FREQUENCY and
>> BT_PRIORITY lines which are relevant for 3-wire coexistence?
>
> The weight register is still used. I just don't quite know what the
> table mapping is.
>
> But specifically, as you're effectively trying to implement "bluetooth
> stomps everything", what you really want is a table where bt wins each
> round, except perhaps for beacon interval (so you send out beacons
> reliably.) There should already be static stomp register values for
> "BT wins all" and "Wifi wins all." That's all you should need to write
> into that register.
>
>
>
>
> Adrian
>
>