[PATCH v2 0/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[PATCH v2 0/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Stefano Radaelli]

While validating SCO audio on a platform using TI WL183x Bluetooth
modules with the hci_ll driver, we observed failures when the
HCI Enhanced Setup Synchronous Connection command was used.

Although the controller advertises support for the command, SCO setup
fails in certain configurations (e.g. BT_VOICE_TRANSPARENT/mSBC).
This matches the scenario described in commit 05abad857277
("Bluetooth: HCI: Add HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN quirk").

Initially, we considered setting the
HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN quirk unconditionally in
hci_ll. However, this would affect all TI controllers handled by the
driver, including configurations where the enhanced setup command
works correctly.

To avoid hardcoding the quirk globally, we first proposed a DT-based
solution. Based on review feedback, the quirk is now enabled
automatically for the affected devices by deducing it from the
compatible string instead.

The issue has been observed on WL1831, WL1835 and WL1837 modules,
therefore the quirk is enabled for:
- "ti,wl1831-st"
- "ti,wl1835-st"
- "ti,wl1837-st"

This keeps the change limited to the affected WL183x family and avoids
impacting other TI controllers handled by hci_ll.

v1->v2:
 - Remove DT property, used compatible instead

v1:
Link: https://patchwork.kernel.org/project/bluetooth/patch/db4c7eab9d0c2f71eb61baff240957596f099401.1771847350.git.stefano.r@variscite.com/

Stefano Radaelli (1):
  Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

 drivers/bluetooth/hci_ll.c | 10 ++++++++++
 1 file changed, 10 insertions(+)


base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
-- 
2.47.3

[PATCH v2 1/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Stefano Radaelli]

From: Stefano Radaelli <stefano.r@variscite.com>

TI WL183x controllers advertise support for the HCI Enhanced Setup
Synchronous Connection command, but SCO setup fails when the enhanced
path is used. The only working configuration is to fall back to the
legacy HCI Setup Synchronous Connection (0x0028).

This matches the scenario described in commit 05abad857277
("Bluetooth: HCI: Add HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN quirk").

Enable HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN automatically for
devices compatible with:
  - ti,wl1831-st
  - ti,wl1835-st
  - ti,wl1837-st

Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
---
v1->v2:
 - 

 drivers/bluetooth/hci_ll.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
index 91acf24f1ef5..6f060eec3b81 100644
--- a/drivers/bluetooth/hci_ll.c
+++ b/drivers/bluetooth/hci_ll.c
@@ -68,6 +68,7 @@ struct ll_device {
 	struct gpio_desc *enable_gpio;
 	struct clk *ext_clk;
 	bdaddr_t bdaddr;
+	bool broken_enhanced_setup;
 };
 
 struct ll_struct {
@@ -656,6 +657,10 @@ static int ll_setup(struct hci_uart *hu)
 			hci_set_quirk(hu->hdev, HCI_QUIRK_INVALID_BDADDR);
 	}
 
+	if (lldev->broken_enhanced_setup)
+		hci_set_quirk(hu->hdev,
+			      HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN);
+
 	/* Operational speed if any */
 	if (hu->oper_speed)
 		speed = hu->oper_speed;
@@ -710,6 +715,11 @@ static int hci_ti_probe(struct serdev_device *serdev)
 	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
 	hci_uart_set_speeds(hu, 115200, max_speed);
 
+	if (of_device_is_compatible(serdev->dev.of_node, "ti,wl1831-st") ||
+	    of_device_is_compatible(serdev->dev.of_node, "ti,wl1835-st") ||
+	    of_device_is_compatible(serdev->dev.of_node, "ti,wl1837-st"))
+		lldev->broken_enhanced_setup = true;
+
 	/* optional BD address from nvram */
 	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
 	if (IS_ERR(bdaddr_cell)) {
-- 
2.47.3

Re: [PATCH v2 1/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Stefano Radaelli]

Hi,

On Tue, Feb 24, 2026 at 12:12:35PM +0100, Stefano Radaelli wrote:
> From: Stefano Radaelli <stefano.r@variscite.com>
> 
> TI WL183x controllers advertise support for the HCI Enhanced Setup
> Synchronous Connection command, but SCO setup fails when the enhanced
> path is used. The only working configuration is to fall back to the
> legacy HCI Setup Synchronous Connection (0x0028).
> 
> This matches the scenario described in commit 05abad857277
> ("Bluetooth: HCI: Add HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN quirk").
> 
> Enable HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN automatically for
> devices compatible with:
>   - ti,wl1831-st
>   - ti,wl1835-st
>   - ti,wl1837-st
> 
> Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
> ---
> v1->v2:
>  - 
> 
>  drivers/bluetooth/hci_ll.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
> index 91acf24f1ef5..6f060eec3b81 100644
> --- a/drivers/bluetooth/hci_ll.c
> +++ b/drivers/bluetooth/hci_ll.c
> @@ -68,6 +68,7 @@ struct ll_device {
>  	struct gpio_desc *enable_gpio;
>  	struct clk *ext_clk;
>  	bdaddr_t bdaddr;
> +	bool broken_enhanced_setup;
>  };
>  
>  struct ll_struct {
> @@ -656,6 +657,10 @@ static int ll_setup(struct hci_uart *hu)
>  			hci_set_quirk(hu->hdev, HCI_QUIRK_INVALID_BDADDR);
>  	}
>  
> +	if (lldev->broken_enhanced_setup)
> +		hci_set_quirk(hu->hdev,
> +			      HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN);
> +
>  	/* Operational speed if any */
>  	if (hu->oper_speed)
>  		speed = hu->oper_speed;
> @@ -710,6 +715,11 @@ static int hci_ti_probe(struct serdev_device *serdev)
>  	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
>  	hci_uart_set_speeds(hu, 115200, max_speed);
>  
> +	if (of_device_is_compatible(serdev->dev.of_node, "ti,wl1831-st") ||
> +	    of_device_is_compatible(serdev->dev.of_node, "ti,wl1835-st") ||
> +	    of_device_is_compatible(serdev->dev.of_node, "ti,wl1837-st"))
> +		lldev->broken_enhanced_setup = true;
> +
>  	/* optional BD address from nvram */
>  	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
>  	if (IS_ERR(bdaddr_cell)) {
> -- 
> 2.47.3
> 

I noticed that this patch has not received feedback and is now marked as
archived in patchwork.

I also saw that the CI reported some test failures (e.g. mgmt-tester and
others), and I was wondering if this might be the reason why it has not
been considered.

Could you please let me know if I should address those issues or if any
changes are needed for this patch?

Thanks,
Stefano

Re: [PATCH v2 1/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Luiz Augusto von Dentz]

Hi Stefano,

On Mon, Mar 30, 2026 at 9:05 AM Stefano Radaelli
<stefano.radaelli21@gmail.com> wrote:
>
> Hi,
>
> On Tue, Feb 24, 2026 at 12:12:35PM +0100, Stefano Radaelli wrote:
> > From: Stefano Radaelli <stefano.r@variscite.com>
> >
> > TI WL183x controllers advertise support for the HCI Enhanced Setup
> > Synchronous Connection command, but SCO setup fails when the enhanced
> > path is used. The only working configuration is to fall back to the
> > legacy HCI Setup Synchronous Connection (0x0028).
> >
> > This matches the scenario described in commit 05abad857277
> > ("Bluetooth: HCI: Add HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN quirk").
> >
> > Enable HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN automatically for
> > devices compatible with:
> >   - ti,wl1831-st
> >   - ti,wl1835-st
> >   - ti,wl1837-st
> >
> > Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
> > ---
> > v1->v2:
> >  -
> >
> >  drivers/bluetooth/hci_ll.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
> > index 91acf24f1ef5..6f060eec3b81 100644
> > --- a/drivers/bluetooth/hci_ll.c
> > +++ b/drivers/bluetooth/hci_ll.c
> > @@ -68,6 +68,7 @@ struct ll_device {
> >       struct gpio_desc *enable_gpio;
> >       struct clk *ext_clk;
> >       bdaddr_t bdaddr;
> > +     bool broken_enhanced_setup;
> >  };
> >
> >  struct ll_struct {
> > @@ -656,6 +657,10 @@ static int ll_setup(struct hci_uart *hu)
> >                       hci_set_quirk(hu->hdev, HCI_QUIRK_INVALID_BDADDR);
> >       }
> >
> > +     if (lldev->broken_enhanced_setup)
> > +             hci_set_quirk(hu->hdev,
> > +                           HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN);
> > +
> >       /* Operational speed if any */
> >       if (hu->oper_speed)
> >               speed = hu->oper_speed;
> > @@ -710,6 +715,11 @@ static int hci_ti_probe(struct serdev_device *serdev)
> >       of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
> >       hci_uart_set_speeds(hu, 115200, max_speed);
> >
> > +     if (of_device_is_compatible(serdev->dev.of_node, "ti,wl1831-st") ||
> > +         of_device_is_compatible(serdev->dev.of_node, "ti,wl1835-st") ||
> > +         of_device_is_compatible(serdev->dev.of_node, "ti,wl1837-st"))
> > +             lldev->broken_enhanced_setup = true;
> > +
> >       /* optional BD address from nvram */
> >       bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
> >       if (IS_ERR(bdaddr_cell)) {
> > --
> > 2.47.3
> >
>
> I noticed that this patch has not received feedback and is now marked as
> archived in patchwork.
>
> I also saw that the CI reported some test failures (e.g. mgmt-tester and
> others), and I was wondering if this might be the reason why it has not
> been considered.
>
> Could you please let me know if I should address those issues or if any
> changes are needed for this patch?

Please resend.

> Thanks,
> Stefano



-- 
Luiz Augusto von Dentz

[PATCH v2 0/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Stefano Radaelli]

While validating SCO audio on a platform using TI WL183x Bluetooth
modules with the hci_ll driver, we observed failures when the
HCI Enhanced Setup Synchronous Connection command was used.

Although the controller advertises support for the command, SCO setup
fails in certain configurations (e.g. BT_VOICE_TRANSPARENT/mSBC).
This matches the scenario described in commit 05abad857277
("Bluetooth: HCI: Add HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN quirk").

Initially, we considered setting the
HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN quirk unconditionally in
hci_ll. However, this would affect all TI controllers handled by the
driver, including configurations where the enhanced setup command
works correctly.

To avoid hardcoding the quirk globally, we first proposed a DT-based
solution. Based on review feedback, the quirk is now enabled
automatically for the affected devices by deducing it from the
compatible string instead.

The issue has been observed on WL1831, WL1835 and WL1837 modules,
therefore the quirk is enabled for:
- "ti,wl1831-st"
- "ti,wl1835-st"
- "ti,wl1837-st"

This keeps the change limited to the affected WL183x family and avoids
impacting other TI controllers handled by hci_ll.

v1->v2:
 - Remove DT property, used compatible instead

v1:
Link: https://patchwork.kernel.org/project/bluetooth/patch/db4c7eab9d0c2f71eb61baff240957596f099401.1771847350.git.stefano.r@variscite.com/

Stefano Radaelli (1):
  Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

 drivers/bluetooth/hci_ll.c | 10 ++++++++++
 1 file changed, 10 insertions(+)


base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
-- 
2.47.3

[PATCH v2 1/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Stefano Radaelli]

From: Stefano Radaelli <stefano.r@variscite.com>

TI WL183x controllers advertise support for the HCI Enhanced Setup
Synchronous Connection command, but SCO setup fails when the enhanced
path is used. The only working configuration is to fall back to the
legacy HCI Setup Synchronous Connection (0x0028).

This matches the scenario described in commit 05abad857277
("Bluetooth: HCI: Add HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN quirk").

Enable HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN automatically for
devices compatible with:
  - ti,wl1831-st
  - ti,wl1835-st
  - ti,wl1837-st

Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
---
v1->v2:
 - 

 drivers/bluetooth/hci_ll.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
index 91acf24f1ef5..6f060eec3b81 100644
--- a/drivers/bluetooth/hci_ll.c
+++ b/drivers/bluetooth/hci_ll.c
@@ -68,6 +68,7 @@ struct ll_device {
 	struct gpio_desc *enable_gpio;
 	struct clk *ext_clk;
 	bdaddr_t bdaddr;
+	bool broken_enhanced_setup;
 };
 
 struct ll_struct {
@@ -656,6 +657,10 @@ static int ll_setup(struct hci_uart *hu)
 			hci_set_quirk(hu->hdev, HCI_QUIRK_INVALID_BDADDR);
 	}
 
+	if (lldev->broken_enhanced_setup)
+		hci_set_quirk(hu->hdev,
+			      HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN);
+
 	/* Operational speed if any */
 	if (hu->oper_speed)
 		speed = hu->oper_speed;
@@ -710,6 +715,11 @@ static int hci_ti_probe(struct serdev_device *serdev)
 	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
 	hci_uart_set_speeds(hu, 115200, max_speed);
 
+	if (of_device_is_compatible(serdev->dev.of_node, "ti,wl1831-st") ||
+	    of_device_is_compatible(serdev->dev.of_node, "ti,wl1835-st") ||
+	    of_device_is_compatible(serdev->dev.of_node, "ti,wl1837-st"))
+		lldev->broken_enhanced_setup = true;
+
 	/* optional BD address from nvram */
 	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
 	if (IS_ERR(bdaddr_cell)) {
-- 
2.47.3

Re: [PATCH v2 1/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Stefano Radaelli]

Hi Luiz,

On Thu, Apr 02, 2026 at 01:38:06PM -0400, Luiz Augusto von Dentz wrote:
> 
> Please resend.
> 

I've re-sent the patch.

Thank you,
Best Regards,
Stefano

Re: [PATCH v2 1/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Paul Menzel]

Dear Stefano,


Thank you for the patch.

Am 02.04.26 um 20:47 schrieb Stefano Radaelli:
> From: Stefano Radaelli <stefano.r@variscite.com>
> 
> TI WL183x controllers advertise support for the HCI Enhanced Setup
> Synchronous Connection command, but SCO setup fails when the enhanced
> path is used. The only working configuration is to fall back to the
> legacy HCI Setup Synchronous Connection (0x0028).

Do you have a reproducer?

Have you contacted TI about this?

> This matches the scenario described in commit 05abad857277
> ("Bluetooth: HCI: Add HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN quirk").
> 
> Enable HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN automatically for
> devices compatible with:
>    - ti,wl1831-st
>    - ti,wl1835-st
>    - ti,wl1837-st

Do you have an example device, that uses one of these? Also, do you know 
of TI device, where the HCI Enhanced Setup Synchronous Connection 
command works?

> Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
> ---
> v1->v2:
>   -

For the future, if you just resend, just add the tag [RESEND] instead of 
v2, so it’s clear no changes were made.

>   drivers/bluetooth/hci_ll.c | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
> index 91acf24f1ef5..6f060eec3b81 100644
> --- a/drivers/bluetooth/hci_ll.c
> +++ b/drivers/bluetooth/hci_ll.c
> @@ -68,6 +68,7 @@ struct ll_device {
>   	struct gpio_desc *enable_gpio;
>   	struct clk *ext_clk;
>   	bdaddr_t bdaddr;
> +	bool broken_enhanced_setup;
>   };
>   
>   struct ll_struct {
> @@ -656,6 +657,10 @@ static int ll_setup(struct hci_uart *hu)
>   			hci_set_quirk(hu->hdev, HCI_QUIRK_INVALID_BDADDR);
>   	}
>   
> +	if (lldev->broken_enhanced_setup)
> +		hci_set_quirk(hu->hdev,
> +			      HCI_QUIRK_BROKEN_ENHANCED_SETUP_SYNC_CONN);
> +
>   	/* Operational speed if any */
>   	if (hu->oper_speed)
>   		speed = hu->oper_speed;
> @@ -710,6 +715,11 @@ static int hci_ti_probe(struct serdev_device *serdev)
>   	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
>   	hci_uart_set_speeds(hu, 115200, max_speed);
>   
> +	if (of_device_is_compatible(serdev->dev.of_node, "ti,wl1831-st") ||
> +	    of_device_is_compatible(serdev->dev.of_node, "ti,wl1835-st") ||
> +	    of_device_is_compatible(serdev->dev.of_node, "ti,wl1837-st"))
> +		lldev->broken_enhanced_setup = true;
> +
>   	/* optional BD address from nvram */
>   	bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
>   	if (IS_ERR(bdaddr_cell)) {

Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>


Kind regards,

Paul

Re: [PATCH v2 1/1] Bluetooth: hci_ll: Enable BROKEN_ENHANCED_SETUP_SYNC_CONN for WL183x

[Stefano Radaelli]

Hi Paul,

On Thu, Apr 02, 2026 at 10:51:01PM +0200, Paul Menzel wrote:
> 
> Do you have a reproducer?
> 

Yes,
the issue can be reproduced on our Variscite platforms using TI WL183x
modules (e.g. VAR-SOM-MX6). When establishing an SCO connection using
the HCI Enhanced Setup Synchronous Connection command.

Forcing the legacy HCI Setup Synchronous Connection (0x0028) instead
restores correct SCO operation.

> Have you contacted TI about this?
> 

No, we have not contacted TI.

WL183x devices are quite old (released more than 10 years ago), and the
latest available firmware is also quite dated and predates the
introduction of the Enhanced Setup Synchronous Connection handling in
the Linux kernel.

Given this, these devices cannot realistically work correctly with this
command unless a new firmware update is provided by TI, which seems
unlikely at this point.

> 
> Do you have an example device, that uses one of these? 

Yes, for example the VAR-SOM-MX6, which integrates WL183x modules.
The issue has been consistently observed across our platforms using
WL1831, WL1835 and WL1837 modules.

>Also, do you know of
> TI device, where the HCI Enhanced Setup Synchronous Connection command
> works?
> 

At the moment I do not have access to other TI Bluetooth families using
this driver to verify whether the enhanced command works correctly on
newer devices.

For this reason, the patch limits the quirk only to the WL183x family,
based on the compatible string, and does not affect other TI devices
handled by hci_ll. Additional compatibles can be added in the future if
similar behaviour is observed on other controllers.

Thanks for your review!

Best Regards,
Stefano