Re: [PATCH] ath9k: turn on btcoex_enable as default

5 messages, 3 authors, 2018-08-23 · open the first message on its own page

Re: [PATCH] ath9k: turn on btcoex_enable as default

From: Kalle Valo <hidden>
Date: 2018-02-09 07:16:42

Kai Heng Feng [off-list ref] writes:
Hi Felix,
quoted
On Feb 8, 2018, at 7:02 PM, Felix Fietkau [off-list ref] wrote:

On 2018-02-08 06:28, Kai-Heng Feng wrote:
quoted
Without btcoex_enable, WiFi activies make both WiFi and Bluetooth
unstable if there's a bluetooth connection.

Enable this option when bt_ant_diversity is disabled.

BugLink: https://bugs.launchpad.net/bugs/1746164
Signed-off-by: Kai-Heng Feng <redacted>
I think this might cause regressions on devices that don't have
bluetooth. This probably either needs more EEPROM checks, or something
to selectively enable it only on affected platforms.
I think it’s better not to use dmi_match. This issue should affect
more ath9k. And bluetooth peripherals are more than ever now, so it
would be great to use BT out of the box.
Sure, but we have to make sure that we don't create regressions on
existing systems. For example, did you test this with any system which
don't support btcoex? (just asking, haven't tested this myself)

-- 
Kalle Valo

Re: [PATCH] ath9k: turn on btcoex_enable as default

From: Kai Heng Feng <hidden>
Date: 2018-02-10 13:56:46

On 9 Feb 2018, at 3:16 PM, Kalle Valo [off-list ref] wrote:
Sure, but we have to make sure that we don't create regressions on
existing systems. For example, did you test this with any system which
don't support btcoex? (just asking, haven't tested this myself)
No not really, but I will definitely test it.
The only module I have that uses ath9k is Dell’s DW1707.
How do I check if it support btcoex or not?

(I resend the mail because my last mail get changed to HTML by my mail client)

Kai-Heng
-- 
Kalle Valo

Re: [PATCH] ath9k: turn on btcoex_enable as default

From: Felix Fietkau <nbd@nbd.name>
Date: 2018-02-10 14:05:11

On 2018-02-10 14:56, Kai Heng Feng wrote:
quoted
On 9 Feb 2018, at 3:16 PM, Kalle Valo [off-list ref] wrote:
Sure, but we have to make sure that we don't create regressions on
existing systems. For example, did you test this with any system which
don't support btcoex? (just asking, haven't tested this myself)
No not really, but I will definitely test it.
The only module I have that uses ath9k is Dell’s DW1707.
How do I check if it support btcoex or not?
I just reviewed the code again, and I am sure that we cannot merge this
patch. Enabling the btcoex parameter makes the driver enable a whole
bunch of code starting timers, listening to some GPIOs, etc.

On non-btcoex systems, some of those GPIOs might be floating or even
connected to different things, which could cause a lot of undefined
behavior.

This is simply too big a risk, so there absolutely needs to be a
whitelist for systems that need this, otherwise it has to remain
disabled by default.

- Felix

Re: [PATCH] ath9k: turn on btcoex_enable as default

From: Kai Heng Feng <hidden>
Date: 2018-02-12 04:16:03

On 10 Feb 2018, at 10:05 PM, Felix Fietkau [off-list ref] wrote:

On 2018-02-10 14:56, Kai Heng Feng wrote:
quoted
quoted
On 9 Feb 2018, at 3:16 PM, Kalle Valo [off-list ref] wrote:
Sure, but we have to make sure that we don't create regressions on
existing systems. For example, did you test this with any system which
don't support btcoex? (just asking, haven't tested this myself)
No not really, but I will definitely test it.
The only module I have that uses ath9k is Dell’s DW1707.
How do I check if it support btcoex or not?
I just reviewed the code again, and I am sure that we cannot merge this
patch. Enabling the btcoex parameter makes the driver enable a whole
bunch of code starting timers, listening to some GPIOs, etc.

On non-btcoex systems, some of those GPIOs might be floating or even
connected to different things, which could cause a lot of undefined
behavior.

This is simply too big a risk, so there absolutely needs to be a
whitelist for systems that need this, otherwise it has to remain
disabled by default.
So what information can we use to whitelist btcoex chips?
Can we get btcoex support status at ath9k probing?

Kai-Heng
- Felix

Re: [PATCH] ath9k: turn on btcoex_enable as default

From: Kai-Heng Feng <hidden>
Date: 2018-08-23 01:34:07

at 12:15, Kai Heng Feng [off-list ref] wrote:
quoted
On 10 Feb 2018, at 10:05 PM, Felix Fietkau [off-list ref] wrote:

On 2018-02-10 14:56, Kai Heng Feng wrote:
quoted
quoted
On 9 Feb 2018, at 3:16 PM, Kalle Valo [off-list ref] wrote:
Sure, but we have to make sure that we don't create regressions on
existing systems. For example, did you test this with any system which
don't support btcoex? (just asking, haven't tested this myself)
No not really, but I will definitely test it.
The only module I have that uses ath9k is Dell’s DW1707.
How do I check if it support btcoex or not?
I just reviewed the code again, and I am sure that we cannot merge this
patch. Enabling the btcoex parameter makes the driver enable a whole
bunch of code starting timers, listening to some GPIOs, etc.

On non-btcoex systems, some of those GPIOs might be floating or even
connected to different things, which could cause a lot of undefined
behavior.

This is simply too big a risk, so there absolutely needs to be a
whitelist for systems that need this, otherwise it has to remain
disabled by default.
So what information can we use to whitelist btcoex chips?
Can we get btcoex support status at ath9k probing?
Sorry for bringing this up again.

Is DMI based match an acceptable approach for ath9k?

Kai-Heng
Kai-Heng
quoted
- Felix
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