Re: [PATCH v1 3/3] Bluetooth: hci_qca: WAR to handle WCN6750 HW issue

["mka@chromium.org" <mka@chromium.org>]

On Thu, Oct 13, 2022 at 01:06:41PM -0700, Luiz Augusto von Dentz wrote:
> Hi,
> 
> On Thu, Oct 13, 2022 at 12:29 PM mka@chromium.org <mka@chromium.org> wrote:
> >
> > On Wed, Jun 22, 2022 at 07:27:21AM +0000, Balakrishna Godavarthi (QUIC) wrote:
> > > Hi Marcel/Miao,
> > >
> > > We are working on new driver, by 7/29 we will submit initial patch for review.
> >
> > Has this ever been sent? I skimmed through the list archives and couldn't find it.
> 
> If you are asking if it was applied, not it wasn't, it probably needs
> to be resend since we were expecting a follow up on the set.

Sorry, if I wasn't clear, my question was about the new serdev based driver
which was supposed to be posted by 7/29.

> > > -----Original Message-----
> > > From: Miao-chen Chou <mcchou@chromium.org>
> > > Sent: Tuesday, May 10, 2022 8:47 AM
> > > To: Balakrishna Godavarthi (QUIC) <quic_bgodavar@quicinc.com>
> > > Cc: Marcel Holtmann <marcel@holtmann.org>; Andy Gross <agross@kernel.org>; robh+dt@kernel.org; bjorn.andersson@linaro.org; linux-arm-msm@vger.kernel.org; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; Johan Hedberg <johan.hedberg@gmail.com>; mka@chromium.org; linux-bluetooth@vger.kernel.org; Hemant Gupta (QUIC) <quic_hemantg@quicinc.com>; Sai Teja Aluvala (Temp) (QUIC) <quic_saluvala@quicinc.com>; quic_rjliao <quic_rjliao@quicinc.com>; Alain Michaud <alainmichaud@google.com>; Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> > > Subject: Re: [PATCH v1 3/3] Bluetooth: hci_qca: WAR to handle WCN6750 HW issue
> > >
> > > Hi Bala,
> > >
> > > When is the estimated start date and timeline of the driver development?
> > >
> > > Thanks,
> > > Miao
> > >
> > > On Fri, Apr 29, 2022 at 8:09 PM Balakrishna Godavarthi (QUIC) <quic_bgodavar@quicinc.com> wrote:
> > > >
> > > > Hi Marcel,
> > > >
> > > > -----Original Message-----
> > > > From: Marcel Holtmann <marcel@holtmann.org>
> > > > Sent: Friday, April 29, 2022 8:24 PM
> > > > To: Balakrishna Godavarthi (QUIC) <quic_bgodavar@quicinc.com>
> > > > Cc: Andy Gross <agross@kernel.org>; robh+dt@kernel.org;
> > > > bjorn.andersson@linaro.org; linux-arm-msm@vger.kernel.org;
> > > > devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; Johan
> > > > Hedberg <johan.hedberg@gmail.com>; mka@chromium.org;
> > > > linux-bluetooth@vger.kernel.org; Hemant Gupta (QUIC)
> > > > <quic_hemantg@quicinc.com>; Sai Teja Aluvala (Temp) (QUIC)
> > > > <quic_saluvala@quicinc.com>; quic_rjliao <quic_rjliao@quicinc.com>;
> > > > mcchou@chromium.org
> > > > Subject: Re: [PATCH v1 3/3] Bluetooth: hci_qca: WAR to handle WCN6750
> > > > HW issue
> > > >
> > > > Hi Balakrishna,
> > > >
> > > > > The patch is workaround for hardware issue on WCN6750.
> > > > > On WCN6750 sometimes observed AON power source takes 100ms time to
> > > > > fully discharge voltage during OFF. As WCN6750 is combo chip for
> > > > > WLAN and BT. If any of the tech area ON is triggered during
> > > > > discharge phase, it fails to turn ON.
> > > > > To overcome this hardware issue, During BT ON, driver check for
> > > > > WLAN_EN pin status. If it high, it will pull BT_EN to high
> > > > > immediately else it will wait for 100ms assuming WLAN was just
> > > > > powered OFF and then BT_EN will be pulled to high.
> > > > >
> > > > > Fixes: d8f97da1b92d2 ("Bluetooth: hci_qca: Add support for QTI
> > > > > Bluetooth chip wcn6750")
> > > > > Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
> > > > > Signed-off-by: Sai Teja Aluvala <quic_saluvala@quicinc.com>
> > > > > Signed-off-by: Balakrishna Godavarthi <quic_bgodavar@quicinc.com>
> > > > > ---
> > > > > drivers/bluetooth/hci_qca.c | 30 ++++++++++++++++++++++++------
> > > > > 1 file changed, 24 insertions(+), 6 deletions(-)
> > > > >
> > > > > diff --git a/drivers/bluetooth/hci_qca.c
> > > > > b/drivers/bluetooth/hci_qca.c index eab34e2..c3862d1 100644
> > > > > --- a/drivers/bluetooth/hci_qca.c
> > > > > +++ b/drivers/bluetooth/hci_qca.c
> > > > > @@ -219,6 +219,7 @@ struct qca_serdev {
> > > > >       struct hci_uart  serdev_hu;
> > > > >       struct gpio_desc *bt_en;
> > > > >       struct gpio_desc *sw_ctrl;
> > > > > +     struct gpio_desc *wlan_en;
> > > > >       struct clk       *susclk;
> > > > >       enum qca_btsoc_type btsoc_type;
> > > > >       struct qca_power *bt_power;
> > > >
> > > > I am really against these intermixing of Bluetooth and WiFi details. There is work ongoing to do some sequence power procedure. Maybe that is something you should look into. This is a mess.
> > > >
> > > > And again, we are still hacking around hci_qca.c instead of writing a clean serdev only driver for this hardware. I have the feeling that nobody listens to review comments these days. It is just hacking patches together to get hardware enabled somehow and then disappear.
> > > >
> > > > [Bala]: We are working on serdev like driver for our QCA platform.  We are in initial stages of discussion, and soon we will start the driver development work.
> > > > In mean to stop stability or functional issues we are trying to add these HACKs in QCA driver.
> > > >
> > > > Regards
> > > >
> > > > Marcel
> > > >
> 
> 
> 
> -- 
> Luiz Augusto von Dentz