linux-kernel - Re: [PATCH] power: sequencing: qcom-wcn: don't request BT enable GPIOs for wcn7850

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Message-ID: <CAA8EJpqk+yko_jqyRFo4sFJgtz+YZyEPh2sOEcDa-cYD3pGtnA@mail.gmail.com>
Date: Tue, 2 Jul 2024 16:08:07 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Krzysztof Kozlowski <krzk@...nel.org>, Amit Pundir <amit.pundir@...aro.org>, linux-pm@...r.kernel.org, 
	linux-kernel@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH] power: sequencing: qcom-wcn: don't request BT enable
 GPIOs for wcn7850

On Tue, 2 Jul 2024 at 14:48, Bartosz Golaszewski <brgl@...ev.pl> wrote:
>
> On Tue, Jul 2, 2024 at 1:42 PM Dmitry Baryshkov
> <dmitry.baryshkov@...aro.org> wrote:
> >
> > On Tue, 2 Jul 2024 at 14:41, Bartosz Golaszewski <brgl@...ev.pl> wrote:
> > >
> > > From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> > >
> > > Due to having many existing users of wcn7850 in the kernel, conversion
> > > of the hci_qca driver to using pwrseq exclusively must be done
> > > carefully. Right now, the Bluetooth driver requests and controls the BT
> > > enable GPIO and so the PMU pwrseq driver must not do it or we will run
> > > into problems depending on the probe ordering.
> > >
> > > Add a flag that tells the driver not to request the BT-enable GPIO. We
> > > will remove it once the conversion of the Bluetooth driver is complete.
> >
> > This will not prevent the pinctrl conflict if both PMU and BT devices
> > declare pinctrl for the BT_EN pin.
> >
>
> Hmm... So maybe we'll need to modify the BT driver after all. Should
> we see if we have the enable-gpios property in hci_qca and - if not -
> try to use the power sequencer? Or prioritize the sequencer first and
> if it doesn't match, then fall-back to the current mode of operation?

I'd say, try powerseq first, then fallback to enable-gpio.

-- 
With best wishes
Dmitry