[PATCH v3 2/5] Bluetooth: add quirk for broken address properties

[PATCH v3 2/5] Bluetooth: add quirk for broken address properties

[Johan Hovold]

Some Bluetooth controllers lack persistent storage for the device
address and instead one can be provided by the boot firmware using the
'local-bd-address' devicetree property.

The Bluetooth devicetree bindings clearly states that the address should
be specified in little-endian order, but due to a long-standing bug in
the Qualcomm driver which reversed the address some boot firmware has
been providing the address in big-endian order instead.

Add a new quirk that can be set on platforms with broken firmware and
use it to reverse the address when parsing the property so that the
underlying driver bug can be fixed.

Fixes: 5c0a1001c8be ("Bluetooth: hci_qca: Add helper to set device address")
Cc: stable@vger.kernel.org      # 5.1
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 include/net/bluetooth/hci.h | 9 +++++++++
 net/bluetooth/hci_sync.c    | 5 ++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index bdee5d649cc6..191077d8d578 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -176,6 +176,15 @@ enum {
 	 */
 	HCI_QUIRK_USE_BDADDR_PROPERTY,
 
+	/* When this quirk is set, the Bluetooth Device Address provided by
+	 * the 'local-bd-address' fwnode property is incorrectly specified in
+	 * big-endian order.
+	 *
+	 * This quirk can be set before hci_register_dev is called or
+	 * during the hdev->setup vendor callback.
+	 */
+	HCI_QUIRK_BDADDR_PROPERTY_BROKEN,
+
 	/* When this quirk is set, the duplicate filtering during
 	 * scanning is based on Bluetooth devices addresses. To allow
 	 * RSSI based updates, restart scanning if needed.
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 5716345a26df..283ae8edc1e5 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -3215,7 +3215,10 @@ static void hci_dev_get_bd_addr_from_property(struct hci_dev *hdev)
 	if (ret < 0 || !bacmp(&ba, BDADDR_ANY))
 		return;
 
-	bacpy(&hdev->public_addr, &ba);
+	if (test_bit(HCI_QUIRK_BDADDR_PROPERTY_BROKEN, &hdev->quirks))
+		baswap(&hdev->public_addr, &ba);
+	else
+		bacpy(&hdev->public_addr, &ba);
 }
 
 struct hci_init_stage {
-- 
2.43.2

Re: [PATCH v3 2/5] Bluetooth: add quirk for broken address properties

[Doug Anderson]

Hi,

On Tue, Mar 19, 2024 at 8:29 AM Johan Hovold <johan+linaro@kernel.org> wrote:
>
> Some Bluetooth controllers lack persistent storage for the device
> address and instead one can be provided by the boot firmware using the
> 'local-bd-address' devicetree property.
>
> The Bluetooth devicetree bindings clearly states that the address should
> be specified in little-endian order, but due to a long-standing bug in
> the Qualcomm driver which reversed the address some boot firmware has
> been providing the address in big-endian order instead.
>
> Add a new quirk that can be set on platforms with broken firmware and
> use it to reverse the address when parsing the property so that the
> underlying driver bug can be fixed.
>
> Fixes: 5c0a1001c8be ("Bluetooth: hci_qca: Add helper to set device address")
> Cc: stable@vger.kernel.org      # 5.1
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>  include/net/bluetooth/hci.h | 9 +++++++++
>  net/bluetooth/hci_sync.c    | 5 ++++-
>  2 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index bdee5d649cc6..191077d8d578 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -176,6 +176,15 @@ enum {
>          */
>         HCI_QUIRK_USE_BDADDR_PROPERTY,
>
> +       /* When this quirk is set, the Bluetooth Device Address provided by
> +        * the 'local-bd-address' fwnode property is incorrectly specified in
> +        * big-endian order.
> +        *
> +        * This quirk can be set before hci_register_dev is called or
> +        * during the hdev->setup vendor callback.
> +        */
> +       HCI_QUIRK_BDADDR_PROPERTY_BROKEN,

Like with the binding, I feel like
"HCI_QUIRK_BDADDR_PROPERTY_BACKWARDS" or
"HCI_QUIRK_BDADDR_PROPERTY_SWAPPED" would be more documenting but I
don't feel strongly.

Reviewed-by: Douglas Anderson <dianders@chromium.org>

Re: [PATCH v3 2/5] Bluetooth: add quirk for broken address properties

[Konrad Dybcio]

On 3/19/24 17:10, Doug Anderson wrote:
> Hi,
> 
> On Tue, Mar 19, 2024 at 8:29 AM Johan Hovold <johan+linaro@kernel.org> wrote:
>>
>> Some Bluetooth controllers lack persistent storage for the device
>> address and instead one can be provided by the boot firmware using the
>> 'local-bd-address' devicetree property.
>>
>> The Bluetooth devicetree bindings clearly states that the address should
>> be specified in little-endian order, but due to a long-standing bug in
>> the Qualcomm driver which reversed the address some boot firmware has
>> been providing the address in big-endian order instead.
>>
>> Add a new quirk that can be set on platforms with broken firmware and
>> use it to reverse the address when parsing the property so that the
>> underlying driver bug can be fixed.
>>
>> Fixes: 5c0a1001c8be ("Bluetooth: hci_qca: Add helper to set device address")
>> Cc: stable@vger.kernel.org      # 5.1
>> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
>> ---
>>   include/net/bluetooth/hci.h | 9 +++++++++
>>   net/bluetooth/hci_sync.c    | 5 ++++-
>>   2 files changed, 13 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
>> index bdee5d649cc6..191077d8d578 100644
>> --- a/include/net/bluetooth/hci.h
>> +++ b/include/net/bluetooth/hci.h
>> @@ -176,6 +176,15 @@ enum {
>>           */
>>          HCI_QUIRK_USE_BDADDR_PROPERTY,
>>
>> +       /* When this quirk is set, the Bluetooth Device Address provided by
>> +        * the 'local-bd-address' fwnode property is incorrectly specified in
>> +        * big-endian order.
>> +        *
>> +        * This quirk can be set before hci_register_dev is called or
>> +        * during the hdev->setup vendor callback.
>> +        */
>> +       HCI_QUIRK_BDADDR_PROPERTY_BROKEN,
> 
> Like with the binding, I feel like
> "HCI_QUIRK_BDADDR_PROPERTY_BACKWARDS" or
> "HCI_QUIRK_BDADDR_PROPERTY_SWAPPED" would be more documenting but I
> don't feel strongly.

Yeah, I thought the same.. and the binding, perhaps could be generic,
as I have a strong suspicion Qualcomm is not the only vendor who
made such oopsies..

Konrad

Re: [PATCH v3 2/5] Bluetooth: add quirk for broken address properties

[Johan Hovold]

On Tue, Mar 19, 2024 at 09:10:23AM -0700, Doug Anderson wrote:
> On Tue, Mar 19, 2024 at 8:29 AM Johan Hovold <johan+linaro@kernel.org> wrote:

> > +       /* When this quirk is set, the Bluetooth Device Address provided by
> > +        * the 'local-bd-address' fwnode property is incorrectly specified in
> > +        * big-endian order.
> > +        *
> > +        * This quirk can be set before hci_register_dev is called or
> > +        * during the hdev->setup vendor callback.
> > +        */
> > +       HCI_QUIRK_BDADDR_PROPERTY_BROKEN,
> 
> Like with the binding, I feel like
> "HCI_QUIRK_BDADDR_PROPERTY_BACKWARDS" or
> "HCI_QUIRK_BDADDR_PROPERTY_SWAPPED" would be more documenting but I
> don't feel strongly.

So, same reasoning here, this it not some quirk that people should go
around setting without first considering to fix their boot firmware.

Johan

Re: [PATCH v3 2/5] Bluetooth: add quirk for broken address properties

[Dmitry Baryshkov]

On Tue, 19 Mar 2024 at 18:26, Johan Hovold <johan@kernel.org> wrote:
>
> On Tue, Mar 19, 2024 at 09:10:23AM -0700, Doug Anderson wrote:
> > On Tue, Mar 19, 2024 at 8:29 AM Johan Hovold <johan+linaro@kernel.org> wrote:
>
> > > +       /* When this quirk is set, the Bluetooth Device Address provided by
> > > +        * the 'local-bd-address' fwnode property is incorrectly specified in
> > > +        * big-endian order.
> > > +        *
> > > +        * This quirk can be set before hci_register_dev is called or
> > > +        * during the hdev->setup vendor callback.
> > > +        */
> > > +       HCI_QUIRK_BDADDR_PROPERTY_BROKEN,
> >
> > Like with the binding, I feel like
> > "HCI_QUIRK_BDADDR_PROPERTY_BACKWARDS" or
> > "HCI_QUIRK_BDADDR_PROPERTY_SWAPPED" would be more documenting but I
> > don't feel strongly.
>
> So, same reasoning here, this it not some quirk that people should go
> around setting without first considering to fix their boot firmware.

The address can be considered broken in many different ways. The name
should still be descriptive enough. If you want to specify that it is
a broken behaviour, please consider something like BROKEN_BE.



-- 
With best wishes
Dmitry

Re: [PATCH v3 2/5] Bluetooth: add quirk for broken address properties

[Johan Hovold]

On Tue, Mar 19, 2024 at 07:01:57PM +0200, Dmitry Baryshkov wrote:
> On Tue, 19 Mar 2024 at 18:26, Johan Hovold <johan@kernel.org> wrote:
> >
> > On Tue, Mar 19, 2024 at 09:10:23AM -0700, Doug Anderson wrote:
> > > On Tue, Mar 19, 2024 at 8:29 AM Johan Hovold <johan+linaro@kernel.org> wrote:
> >
> > > > +       /* When this quirk is set, the Bluetooth Device Address provided by
> > > > +        * the 'local-bd-address' fwnode property is incorrectly specified in
> > > > +        * big-endian order.
> > > > +        *
> > > > +        * This quirk can be set before hci_register_dev is called or
> > > > +        * during the hdev->setup vendor callback.
> > > > +        */
> > > > +       HCI_QUIRK_BDADDR_PROPERTY_BROKEN,
> > >
> > > Like with the binding, I feel like
> > > "HCI_QUIRK_BDADDR_PROPERTY_BACKWARDS" or
> > > "HCI_QUIRK_BDADDR_PROPERTY_SWAPPED" would be more documenting but I
> > > don't feel strongly.
> >
> > So, same reasoning here, this it not some quirk that people should go
> > around setting without first considering to fix their boot firmware.
> 
> The address can be considered broken in many different ways. The name
> should still be descriptive enough. If you want to specify that it is
> a broken behaviour, please consider something like BROKEN_BE.

I doubt that Qualcomm will be able come up with another way to break the
address property. They'd have to try real hard.

And this is an internal define which can be changed at any time. There's
also some worth in keeping it aligned with the DT property, which I'm
more open to renaming (e.g. if the DT maintainers thinks dropping the
vendor prefix makes sense).

The alternative I considered but rejected was something like
"local-bd-address-be" as that would be too neutral.

Perhaps "local-bd-address-reversed" would at least signal that something
is backwards, but I still fear that that may be too subtle.

Johan

Re: [PATCH v3 2/5] Bluetooth: add quirk for broken address properties

[Luiz Augusto von Dentz]

 Hi,

On Tue, Mar 19, 2024 at 4:26 PM Johan Hovold <johan@kernel.org> wrote:
>
> On Tue, Mar 19, 2024 at 09:10:23AM -0700, Doug Anderson wrote:
> > On Tue, Mar 19, 2024 at 8:29 AM Johan Hovold <johan+linaro@kernel.org> wrote:
>
> > > +       /* When this quirk is set, the Bluetooth Device Address provided by
> > > +        * the 'local-bd-address' fwnode property is incorrectly specified in
> > > +        * big-endian order.
> > > +        *
> > > +        * This quirk can be set before hci_register_dev is called or
> > > +        * during the hdev->setup vendor callback.
> > > +        */
> > > +       HCI_QUIRK_BDADDR_PROPERTY_BROKEN,
> >
> > Like with the binding, I feel like
> > "HCI_QUIRK_BDADDR_PROPERTY_BACKWARDS" or
> > "HCI_QUIRK_BDADDR_PROPERTY_SWAPPED" would be more documenting but I
> > don't feel strongly.
>
> So, same reasoning here, this it not some quirk that people should go
> around setting without first considering to fix their boot firmware.

Or we just change its meaning to say what byteorder is the BDADDR e.g:
HCI_QUIRK_BDADDR_PROPERTY_BYTEORDER=be

> Johan



-- 
Luiz Augusto von Dentz

Re: [PATCH v3 2/5] Bluetooth: add quirk for broken address properties

[Luiz Augusto von Dentz]

On Tue, Mar 19, 2024 at 5:02 PM Luiz Augusto von Dentz
<luiz.dentz@gmail.com> wrote:
>
>  Hi,
>
> On Tue, Mar 19, 2024 at 4:26 PM Johan Hovold <johan@kernel.org> wrote:
> >
> > On Tue, Mar 19, 2024 at 09:10:23AM -0700, Doug Anderson wrote:
> > > On Tue, Mar 19, 2024 at 8:29 AM Johan Hovold <johan+linaro@kernel.org> wrote:
> >
> > > > +       /* When this quirk is set, the Bluetooth Device Address provided by
> > > > +        * the 'local-bd-address' fwnode property is incorrectly specified in
> > > > +        * big-endian order.
> > > > +        *
> > > > +        * This quirk can be set before hci_register_dev is called or
> > > > +        * during the hdev->setup vendor callback.
> > > > +        */
> > > > +       HCI_QUIRK_BDADDR_PROPERTY_BROKEN,
> > >
> > > Like with the binding, I feel like
> > > "HCI_QUIRK_BDADDR_PROPERTY_BACKWARDS" or
> > > "HCI_QUIRK_BDADDR_PROPERTY_SWAPPED" would be more documenting but I
> > > don't feel strongly.
> >
> > So, same reasoning here, this it not some quirk that people should go
> > around setting without first considering to fix their boot firmware.
>
> Or we just change its meaning to say what byteorder is the BDADDR e.g:
> HCI_QUIRK_BDADDR_PROPERTY_BYTEORDER=be

Ah just ignore, it is a flag not really a property that can assume
different values.

> > Johan
>
>
>
> --
> Luiz Augusto von Dentz



-- 
Luiz Augusto von Dentz

[PATCH v3 3/5] Bluetooth: qca: fix device-address endianness

[Johan Hovold]

The WCN6855 firmware on the Lenovo ThinkPad X13s expects the Bluetooth
device address in big-endian order when setting it using the
EDL_WRITE_BD_ADDR_OPCODE command.

Presumably, this is the case for all non-ROME devices which all use the
EDL_WRITE_BD_ADDR_OPCODE command for this (unlike the ROME devices which
use a different command and expect the address in little-endian order).

Reverse the little-endian address before setting it to make sure that
the address can be configured using tools like btmgmt or using the
'local-bd-address' devicetree property.

Note that this can potentially break systems with boot firmware which
has started relying on the broken behaviour and is incorrectly passing
the address via devicetree in big-endian order.

Fixes: 5c0a1001c8be ("Bluetooth: hci_qca: Add helper to set device address")
Cc: stable@vger.kernel.org      # 5.1
Cc: Balakrishna Godavarthi <quic_bgodavar@quicinc.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Nikita Travkin <nikita@trvn.ru> # sc7180
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/bluetooth/btqca.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/btqca.c b/drivers/bluetooth/btqca.c
index b40b32fa7f1c..19cfc342fc7b 100644
--- a/drivers/bluetooth/btqca.c
+++ b/drivers/bluetooth/btqca.c
@@ -826,11 +826,15 @@ EXPORT_SYMBOL_GPL(qca_uart_setup);
 
 int qca_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
 {
+	bdaddr_t bdaddr_swapped;
 	struct sk_buff *skb;
 	int err;
 
-	skb = __hci_cmd_sync_ev(hdev, EDL_WRITE_BD_ADDR_OPCODE, 6, bdaddr,
-				HCI_EV_VENDOR, HCI_INIT_TIMEOUT);
+	baswap(&bdaddr_swapped, bdaddr);
+
+	skb = __hci_cmd_sync_ev(hdev, EDL_WRITE_BD_ADDR_OPCODE, 6,
+				&bdaddr_swapped, HCI_EV_VENDOR,
+				HCI_INIT_TIMEOUT);
 	if (IS_ERR(skb)) {
 		err = PTR_ERR(skb);
 		bt_dev_err(hdev, "QCA Change address cmd failed (%d)", err);
-- 
2.43.2

Re: [PATCH v3 3/5] Bluetooth: qca: fix device-address endianness

[Doug Anderson]

Hi,

On Tue, Mar 19, 2024 at 8:30 AM Johan Hovold <johan+linaro@kernel.org> wrote:
>
> The WCN6855 firmware on the Lenovo ThinkPad X13s expects the Bluetooth
> device address in big-endian order when setting it using the
> EDL_WRITE_BD_ADDR_OPCODE command.
>
> Presumably, this is the case for all non-ROME devices which all use the
> EDL_WRITE_BD_ADDR_OPCODE command for this (unlike the ROME devices which
> use a different command and expect the address in little-endian order).
>
> Reverse the little-endian address before setting it to make sure that
> the address can be configured using tools like btmgmt or using the
> 'local-bd-address' devicetree property.
>
> Note that this can potentially break systems with boot firmware which
> has started relying on the broken behaviour and is incorrectly passing
> the address via devicetree in big-endian order.
>
> Fixes: 5c0a1001c8be ("Bluetooth: hci_qca: Add helper to set device address")
> Cc: stable@vger.kernel.org      # 5.1
> Cc: Balakrishna Godavarthi <quic_bgodavar@quicinc.com>
> Cc: Matthias Kaehlcke <mka@chromium.org>
> Tested-by: Nikita Travkin <nikita@trvn.ru> # sc7180
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>  drivers/bluetooth/btqca.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)

Personally, I'd prefer it if you didn't break bisectability with your
series. As it is, if someone applies just the first 3 patches they'll
end up with broken Bluetooth.

IMO the order should be:
1. Binding (currently patch #1)
2. Trogdor dt patch, which won't hurt on its own (currently patch #5)
3. Bluetooth subsystem patch handling the quirk (currently patch #2)
4. Qualcomm change to fix the endianness and handle the quirk squashed
into 1 patch (currently patch #3 + #4)

...and the patch that changes the Qualcomm driver should make it
obvious that it depends on the trogdor DT patch in the change
description.

With patches #3 and #4 combined, feel free to add my Reviewed-by tag
as both patches look fine to me.

-Doug

Re: [PATCH v3 3/5] Bluetooth: qca: fix device-address endianness

[Johan Hovold]

On Tue, Mar 19, 2024 at 09:10:38AM -0700, Doug Anderson wrote:
> On Tue, Mar 19, 2024 at 8:30 AM Johan Hovold <johan+linaro@kernel.org> wrote:
> >
> > The WCN6855 firmware on the Lenovo ThinkPad X13s expects the Bluetooth
> > device address in big-endian order when setting it using the
> > EDL_WRITE_BD_ADDR_OPCODE command.
> >
> > Presumably, this is the case for all non-ROME devices which all use the
> > EDL_WRITE_BD_ADDR_OPCODE command for this (unlike the ROME devices which
> > use a different command and expect the address in little-endian order).
> >
> > Reverse the little-endian address before setting it to make sure that
> > the address can be configured using tools like btmgmt or using the
> > 'local-bd-address' devicetree property.
> >
> > Note that this can potentially break systems with boot firmware which
> > has started relying on the broken behaviour and is incorrectly passing
> > the address via devicetree in big-endian order.
> >
> > Fixes: 5c0a1001c8be ("Bluetooth: hci_qca: Add helper to set device address")
> > Cc: stable@vger.kernel.org      # 5.1
> > Cc: Balakrishna Godavarthi <quic_bgodavar@quicinc.com>
> > Cc: Matthias Kaehlcke <mka@chromium.org>
> > Tested-by: Nikita Travkin <nikita@trvn.ru> # sc7180
> > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > ---
> >  drivers/bluetooth/btqca.c | 8 ++++++--
> >  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> Personally, I'd prefer it if you didn't break bisectability with your
> series. As it is, if someone applies just the first 3 patches they'll
> end up with broken Bluetooth.

It doesn't break the build, but yes, the device address would be
reversed for Trogdor machines for two commits and possible break any
previous pairings. That's hardly something to worry about.

So I consider this to be acceptable for sake of clarity, and especially
since these patches will be coming in from separate trees anyway.

> IMO the order should be:
> 1. Binding (currently patch #1)
> 2. Trogdor dt patch, which won't hurt on its own (currently patch #5)
> 3. Bluetooth subsystem patch handling the quirk (currently patch #2)
> 4. Qualcomm change to fix the endianness and handle the quirk squashed
> into 1 patch (currently patch #3 + #4)
> 
> ..and the patch that changes the Qualcomm driver should make it
> obvious that it depends on the trogdor DT patch in the change
> description.
> 
> With patches #3 and #4 combined, feel free to add my Reviewed-by tag
> as both patches look fine to me.

I don't think it's worth spending more time and effort on this issue
(which should have been caught and fixed years ago) for this.

Johan

Re: [PATCH v3 3/5] Bluetooth: qca: fix device-address endianness

[Doug Anderson]

Hi,

On Tue, Mar 19, 2024 at 9:38 AM Johan Hovold <johan@kernel.org> wrote:
>
> On Tue, Mar 19, 2024 at 09:10:38AM -0700, Doug Anderson wrote:
> > On Tue, Mar 19, 2024 at 8:30 AM Johan Hovold <johan+linaro@kernel.org> wrote:
> > >
> > > The WCN6855 firmware on the Lenovo ThinkPad X13s expects the Bluetooth
> > > device address in big-endian order when setting it using the
> > > EDL_WRITE_BD_ADDR_OPCODE command.
> > >
> > > Presumably, this is the case for all non-ROME devices which all use the
> > > EDL_WRITE_BD_ADDR_OPCODE command for this (unlike the ROME devices which
> > > use a different command and expect the address in little-endian order).
> > >
> > > Reverse the little-endian address before setting it to make sure that
> > > the address can be configured using tools like btmgmt or using the
> > > 'local-bd-address' devicetree property.
> > >
> > > Note that this can potentially break systems with boot firmware which
> > > has started relying on the broken behaviour and is incorrectly passing
> > > the address via devicetree in big-endian order.
> > >
> > > Fixes: 5c0a1001c8be ("Bluetooth: hci_qca: Add helper to set device address")
> > > Cc: stable@vger.kernel.org      # 5.1
> > > Cc: Balakrishna Godavarthi <quic_bgodavar@quicinc.com>
> > > Cc: Matthias Kaehlcke <mka@chromium.org>
> > > Tested-by: Nikita Travkin <nikita@trvn.ru> # sc7180
> > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> > > ---
> > >  drivers/bluetooth/btqca.c | 8 ++++++--
> > >  1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > Personally, I'd prefer it if you didn't break bisectability with your
> > series. As it is, if someone applies just the first 3 patches they'll
> > end up with broken Bluetooth.
>
> It doesn't break the build, but yes, the device address would be
> reversed for Trogdor machines for two commits and possible break any
> previous pairings. That's hardly something to worry about.
>
> So I consider this to be acceptable for sake of clarity, and especially
> since these patches will be coming in from separate trees anyway.

I guess I have a different opinion on the matter. I often end up
cherry-picking stuff to older branches and I generally assume that
it's relatively safe to pick the beginning of a series without picking
later patches because I assume everyone has a goal of bisectability.
This breaks that assumption. IMO splitting up the Qualcomm Bluetooth
patch into two patches doesn't help enough with clarity to justify.


> > IMO the order should be:
> > 1. Binding (currently patch #1)
> > 2. Trogdor dt patch, which won't hurt on its own (currently patch #5)
> > 3. Bluetooth subsystem patch handling the quirk (currently patch #2)
> > 4. Qualcomm change to fix the endianness and handle the quirk squashed
> > into 1 patch (currently patch #3 + #4)
> >
> > ..and the patch that changes the Qualcomm driver should make it
> > obvious that it depends on the trogdor DT patch in the change
> > description.
> >
> > With patches #3 and #4 combined, feel free to add my Reviewed-by tag
> > as both patches look fine to me.
>
> I don't think it's worth spending more time and effort on this issue
> (which should have been caught and fixed years ago) for this.

Sure, that's your opinion and if the BT folks agree with you then they
are free to land the patches without my Reviewed-by on them. ;-) Mine
is not a strong Nak but I feel strongly enough that I'd prefer not to
have my Reviewed-by added without the re-organization.

-Doug

Re: [PATCH v3 3/5] Bluetooth: qca: fix device-address endianness

[Johan Hovold]

On Tue, Mar 19, 2024 at 10:12:25AM -0700, Doug Anderson wrote:
> On Tue, Mar 19, 2024 at 9:38 AM Johan Hovold <johan@kernel.org> wrote:
> > On Tue, Mar 19, 2024 at 09:10:38AM -0700, Doug Anderson wrote:

> > > Personally, I'd prefer it if you didn't break bisectability with your
> > > series. As it is, if someone applies just the first 3 patches they'll
> > > end up with broken Bluetooth.
> >
> > It doesn't break the build, but yes, the device address would be
> > reversed for Trogdor machines for two commits and possible break any
> > previous pairings. That's hardly something to worry about.
> >
> > So I consider this to be acceptable for sake of clarity, and especially
> > since these patches will be coming in from separate trees anyway.
> 
> I guess I have a different opinion on the matter. I often end up
> cherry-picking stuff to older branches and I generally assume that
> it's relatively safe to pick the beginning of a series without picking
> later patches because I assume everyone has a goal of bisectability.
> This breaks that assumption. IMO splitting up the Qualcomm Bluetooth
> patch into two patches doesn't help enough with clarity to justify.

I did that in v2 because then the two patches had to be split to
facilitate backporting as wcn3991 support was added later.

But the big issue here is taking the patches through different trees. If
Bjorn could ack the DT patch so that everything goes through the
Bluetooth tree, then I guess I can reorder the DT patch and squash the
two driver patches.

But waiting several weeks just to make sure that the DT patch hits
mainline (and the binding patch before that?) before the driver fixes
can go in just does not seem worth it to me.

> > I don't think it's worth spending more time and effort on this issue
> > (which should have been caught and fixed years ago) for this.
> 
> Sure, that's your opinion and if the BT folks agree with you then they
> are free to land the patches without my Reviewed-by on them. ;-) Mine
> is not a strong Nak but I feel strongly enough that I'd prefer not to
> have my Reviewed-by added without the re-organization.

Of course, understood.

Johan

Re: [PATCH v3 3/5] Bluetooth: qca: fix device-address endianness

[Doug Anderson]

Hi,

On Tue, Mar 19, 2024 at 10:28 AM Johan Hovold <johan@kernel.org> wrote:
>
> > I guess I have a different opinion on the matter. I often end up
> > cherry-picking stuff to older branches and I generally assume that
> > it's relatively safe to pick the beginning of a series without picking
> > later patches because I assume everyone has a goal of bisectability.
> > This breaks that assumption. IMO splitting up the Qualcomm Bluetooth
> > patch into two patches doesn't help enough with clarity to justify.
>
> I did that in v2 because then the two patches had to be split to
> facilitate backporting as wcn3991 support was added later.
>
> But the big issue here is taking the patches through different trees. If
> Bjorn could ack the DT patch so that everything goes through the
> Bluetooth tree, then I guess I can reorder the DT patch and squash the
> two driver patches.
>
> But waiting several weeks just to make sure that the DT patch hits
> mainline (and the binding patch before that?) before the driver fixes
> can go in just does not seem worth it to me.

Personally, I don't care quite as much about them going through the
same tree. It'd be nice, but I agree with you that it's probably not
worth the hassle (though I wouldn't object if Bjorn wanted to Ack the
dts) and it's fine with me if the patches "meet up" in mainline. In my
case, though, I could imagine following the "Link" tag in the patches
and arriving at the mailing list post. That's where I'd go back and
look to see the order which I should apply the patches safely. ...and
I'd prefer that it shows an order that lets things apply safely.

-Doug

[PATCH v3 4/5] Bluetooth: qca: add workaround for broken address properties

[Johan Hovold]

Due to a long-standing bug in the Qualcomm Bluetooth driver, the device
address has so far been reversed when configuring non-ROME controllers.
This, in turn, has led to one vendor reversing the address that the boot
firmware provides using the 'local-bd-address' devicetree property.

The only device affected by this should be the WCN3991 used in some
Chromebooks. As ChromeOS updates the kernel and devicetree in lockstep,
the new 'qcom,local-bd-address-broken' property can be used to determine
if the firmware is buggy so that the underlying driver bug can be fixed
without breaking backwards compatibility.

Set the HCI_QUIRK_BDADDR_PROPERTY_BROKEN quirk for such platforms so
that the address is reversed when parsing the address property.

Fixes: 5c0a1001c8be ("Bluetooth: hci_qca: Add helper to set device address")
Cc: stable@vger.kernel.org      # 5.1
Cc: Balakrishna Godavarthi <quic_bgodavar@quicinc.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/bluetooth/hci_qca.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index f989c05f8177..c73481c57741 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -225,6 +225,7 @@ struct qca_serdev {
 	struct qca_power *bt_power;
 	u32 init_speed;
 	u32 oper_speed;
+	bool bdaddr_property_broken;
 	const char *firmware_name;
 };
 
@@ -1842,6 +1843,7 @@ static int qca_setup(struct hci_uart *hu)
 	const char *firmware_name = qca_get_firmware_name(hu);
 	int ret;
 	struct qca_btsoc_version ver;
+	struct qca_serdev *qcadev;
 	const char *soc_name;
 
 	ret = qca_check_speeds(hu);
@@ -1904,6 +1906,11 @@ static int qca_setup(struct hci_uart *hu)
 	case QCA_WCN6855:
 	case QCA_WCN7850:
 		set_bit(HCI_QUIRK_USE_BDADDR_PROPERTY, &hdev->quirks);
+
+		qcadev = serdev_device_get_drvdata(hu->serdev);
+		if (qcadev->bdaddr_property_broken)
+			set_bit(HCI_QUIRK_BDADDR_PROPERTY_BROKEN, &hdev->quirks);
+
 		hci_set_aosp_capable(hdev);
 
 		ret = qca_read_soc_version(hdev, &ver, soc_type);
@@ -2284,6 +2291,9 @@ static int qca_serdev_probe(struct serdev_device *serdev)
 	if (!qcadev->oper_speed)
 		BT_DBG("UART will pick default operating speed");
 
+	qcadev->bdaddr_property_broken = device_property_read_bool(&serdev->dev,
+			"qcom,local-bd-address-broken");
+
 	if (data)
 		qcadev->btsoc_type = data->soc_type;
 	else
-- 
2.43.2

[PATCH v3 5/5] arm64: dts: qcom: sc7180-trogdor: mark bluetooth address as broken

[Johan Hovold]

Several Qualcomm Bluetooth controllers lack persistent storage for the
device address and instead one can be provided by the boot firmware
using the 'local-bd-address' devicetree property.

The Bluetooth bindings clearly states that the address should be
specified in little-endian order, but due to a long-standing bug in the
Qualcomm driver which reversed the address some boot firmware has been
providing the address in big-endian order instead.

The boot firmware in SC7180 Trogdor Chromebooks is known to be affected
so mark the 'local-bd-address' property as broken to maintain backwards
compatibility with older firmware when fixing the underlying driver bug.

Note that ChromeOS always updates the kernel and devicetree in lockstep
so that there is no need to handle backwards compatibility with older
devicetrees.

Fixes: 7ec3e67307f8 ("arm64: dts: qcom: sc7180-trogdor: add initial trogdor and lazor dt")
Cc: stable@vger.kernel.org      # 5.10
Cc: Rob Clark <robdclark@chromium.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
index 46aaeba28604..ebe37678102f 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
@@ -943,6 +943,8 @@ bluetooth: bluetooth {
 		vddrf-supply = <&pp1300_l2c>;
 		vddch0-supply = <&pp3300_l10c>;
 		max-speed = <3200000>;
+
+		qcom,local-bd-address-broken;
 	};
 };
 
-- 
2.43.2

Re: [PATCH v3 5/5] arm64: dts: qcom: sc7180-trogdor: mark bluetooth address as broken

[Doug Anderson]

Hi,

On Tue, Mar 19, 2024 at 8:29 AM Johan Hovold <johan+linaro@kernel.org> wrote:
>
> Several Qualcomm Bluetooth controllers lack persistent storage for the
> device address and instead one can be provided by the boot firmware
> using the 'local-bd-address' devicetree property.
>
> The Bluetooth bindings clearly states that the address should be
> specified in little-endian order, but due to a long-standing bug in the
> Qualcomm driver which reversed the address some boot firmware has been
> providing the address in big-endian order instead.
>
> The boot firmware in SC7180 Trogdor Chromebooks is known to be affected
> so mark the 'local-bd-address' property as broken to maintain backwards
> compatibility with older firmware when fixing the underlying driver bug.
>
> Note that ChromeOS always updates the kernel and devicetree in lockstep
> so that there is no need to handle backwards compatibility with older
> devicetrees.
>
> Fixes: 7ec3e67307f8 ("arm64: dts: qcom: sc7180-trogdor: add initial trogdor and lazor dt")
> Cc: stable@vger.kernel.org      # 5.10
> Cc: Rob Clark <robdclark@chromium.org>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi | 2 ++
>  1 file changed, 2 insertions(+)

Assuming DT bindings folks Ack the binding, this looks fine to me.

Reviewed-by: Douglas Anderson <dianders@chromium.org>