Re: [PATCH REGRESSION] Revert "ath10k: add quiet mode support for QCA6174/QCA9377"

[Rajkumar Manoharan]

On 2018-11-08 09:30, Brian Norris wrote:
> On Wed, Nov 7, 2018 at 8:32 PM Govind Singh <govinds@xxxxxxxxxxxxxx> 
> wrote:
> > On 2018-11-08 03:00, Rajkumar Manoharan wrote:
> > >
> > > The change "ath10k: add quiet mode support for QCA6174/QCA9377" was
> > > merged even
> > > before full WCN3990 device support was added in ath10k. How come it
> > > could be regression
> > > for WCN3990. I know both are sharing same WMI-TLV interface but
> > > reverting this
> > > will break QCA6174/QCA9377. no?
>
> I don't see how the revert would "break" QCA6174 -- QCA6174 worked
> just fine without this feature and should continue to do so.

I meant that the revert commit remove quiet mode support from QCA6174 & 
QCA9377.

> > This regression is found while we switched from 4.18 + WCN3990
> > back-ports to 4.19.
>
> ^^ What Govind said. WCN3990 support has been trickling in over a few
> releases, and it doesn't seem kosher to allow people to submit
> regressions in the midst of that.
Nobody prefers regression :). WCN3990 support was still in progress, at
the time the commit got merged into upstream. My point is that we can't 
expect
the community to validate the changes against in-progress platform.

> > IMO, we should use (WMI_SERVICE_THERMAL_MGMT | WMI_SERVICE_THERM_THROT 
> > )
> > service bitmap check and call
> > ath10k_thermal_set_throttling only if fw supports THERMAL THROTTLE
> > feature. But we need to ensure all
> > available ath10k fw's are reporting this service.
>
> And the above notes from Govind highlight this -- if the feature was
> not protected by the appropriate service flags, then we can't be sure
> that you didn't break a bunch of other firmware releases out there.
> Linux should not break for everyone just because you spun a firmware
> release.
That is true. Any new features or interface changes in firmware will be
advertised by feature bit. But the quiet param was available in firmware
since first release.

> Of course, I'll leave it up to Kalle as to how he wants to mediate
> this. And if you come up with a solid patch soon that can fix this
> without dropping the feature, then so be it.
Govind is working on to handle this properly either by instantiating
new WMI-TLV table for WCNxxxx or by adding conditional check in exiting 
path.

-Rajkumar