Date:   Tue, 12 Mar 2019 08:52:41 -0700
From:   Matthias Kaehlcke <mka@chromium.org>
To:     rjliao@codeaurora.org
Cc:     Balakrishna Godavarthi <bgodavar@codeaurora.org>,
        marcel@holtmann.org, johan.hedberg@gmail.com,
        linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org,
        hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH v1] Bluetooth: hci_qca: Enable the ldisc for ROME for x86
 platforms.
Message-ID: <20190312155241.GB200579@google.com>
References: <20190307101722.25871-1-bgodavar@codeaurora.org>
 <20190307204224.GD138592@google.com>
 <6e0abe10b3ed44053e92ad6a21c75d93@codeaurora.org>
 <20190308185232.GB69116@google.com>
 <1042d21dde881e886541d32b8f0dff63@codeaurora.org>
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Hi Rocky,

On Tue, Mar 12, 2019 at 05:01:59PM +0800, rjliao@codeaurora.org wrote:
> 在 2019-03-09 02:52，Matthias Kaehlcke 写道：
> > On Fri, Mar 08, 2019 at 10:43:14AM +0530, Balakrishna Godavarthi wrote:
> > > Hi Matthias,
> > > 
> > > On 2019-03-08 02:12, Matthias Kaehlcke wrote:
> > > > Hi Balakrishna,
> > > >
> > > > On Thu, Mar 07, 2019 at 03:47:22PM +0530, Balakrishna Godavarthi wrote:
> > > > > When using btattach to setup Rome over ldisc we observed a crash
> > > > > in qca_setup as it will try to access the serdev which is not
> > > > > available in the ldisc proto. This patch will fix the crash by
> > > > > support both the ldisc and serdev way in the qca hci_uart driver.
> > > > >
> > > > > Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
> > > >
> > > > Oh, I wasn't aware of the instantiation through ldisc and was actually
> > > > considering to *remove* some of the seemingly unnecessary serdev
> > > > checks.
> > > >
> > > > > ---
> > > > >  drivers/bluetooth/hci_qca.c | 47
> > > > > ++++++++++++++++++++++---------------
> > > > >  1 file changed, 28 insertions(+), 19 deletions(-)
> > > > >
> > > > > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> > > > > index 237aea34b69f..0a5c98d46864 100644
> > > > > --- a/drivers/bluetooth/hci_qca.c
> > > > > +++ b/drivers/bluetooth/hci_qca.c
> > > > > @@ -963,7 +963,7 @@ static int qca_set_baudrate(struct hci_dev
> > > > > *hdev, uint8_t baudrate)
> > > > >  {
> > > > >  	struct hci_uart *hu = hci_get_drvdata(hdev);
> > > > >  	struct qca_data *qca = hu->priv;
> > > > > -	struct qca_serdev *qcadev;
> > > > > +	struct qca_serdev *qcadev = NULL;
> > > >
> > > > In many cases the only field that is accessed is qcadev->btsoc_type. I
> > > > think something like 'qca_get_soc_type(struct hci_dev *hdev / struct
> > > > hci_uart *hu)' would make things more readable.
> > > >
> > > [Bala]: sure will update this in other patch once this change is
> > > landed as
> > > this has to
> > >         go in priority as we have crash coming.
> > 
> > That's not how things should work, especially for fairly trivial
> > changes. It requires reviewers to first spent time to review the patch
> > that adds clutter and later spend more time to review the one that
> > removes it. It's also easier to get a clean patch merged in the first
> > place, rather than a noisy one.
> > 
> > Anyway, here is my take at it:
> > https://lore.kernel.org/patchwork/patch/1049014/
> > 
> > Please help with testing for ROME, unless you disagree with the
> > approach.
> > 
> > Thanks
> > 
> > Matthias
> 
> Hi Matthias,
> 
> I will test your patch and update to you, and you are correct that AR3002 is
> not part of Rome family, you should use QCA_ROME as the default return of
> qca_soc_type.

Thanks for the confirmation!

> Could you also loop me in
> https://lore.kernel.org/patchwork/patch/1049014/?

This patch has been superseded by a newer version:

https://lore.kernel.org/patchwork/patch/1049696/

It already landed in bluetooth-next.

Testing with Rome and ldisc would still be appreciated, since I don't
have such a configuration.

Thanks

Matthias