diff mbox series

[1/3] ARM: dts: sun5i: chip: Enable bluetooth

Message ID f26d11e613df7bd55822ff3fb7689e36bf9e4f7a.1681580558.git.noodles@earth.li
State New
Headers show
Series Minor device-tree additions for C.H.I.P | expand

Commit Message

Jonathan McDowell April 15, 2023, 5:46 p.m. UTC
The C.H.I.P has an rtl8723bs device with the bluetooth interface hooked
up on UART3. Support for this didn't exist in mainline when the DTS was
initially added, but it does now, so enable it.

Signed-off-by: Jonathan McDowell <noodles@earth.li>
---
 arch/arm/boot/dts/sun5i-r8-chip.dts | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Andre Przywara April 16, 2023, 12:24 a.m. UTC | #1
On Sat, 15 Apr 2023 18:46:03 +0100
Jonathan McDowell <noodles@earth.li> wrote:

> The C.H.I.P has an rtl8723bs device with the bluetooth interface hooked
> up on UART3. Support for this didn't exist in mainline when the DTS was
> initially added, but it does now, so enable it.
> 
> Signed-off-by: Jonathan McDowell <noodles@earth.li>
> ---
>  arch/arm/boot/dts/sun5i-r8-chip.dts | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/sun5i-r8-chip.dts b/arch/arm/boot/dts/sun5i-r8-chip.dts
> index fd37bd1f3920..4d72a181d8aa 100644
> --- a/arch/arm/boot/dts/sun5i-r8-chip.dts
> +++ b/arch/arm/boot/dts/sun5i-r8-chip.dts
> @@ -255,6 +255,10 @@ &uart3 {
>  	pinctrl-0 = <&uart3_pg_pins>,
>  		    <&uart3_cts_rts_pg_pins>;
>  	status = "okay";
> +
> +	bluetooth {
> +		compatible = "realtek,rtl8723bs-bt";
> +	}

As the kernel test robot already pointed out, there is a semicolon
missing here.
Otherwise looks good (dt-validate passes), but don't know if there are
any wakeup GPIOs connected (can't seem to find a schematic?).

Cheers,
Andre


>  };
>  
>  &usb_otg {
Saravana Kannan April 21, 2023, 10:45 p.m. UTC | #2
On Fri, Apr 21, 2023 at 1:28 AM Jonathan McDowell <noodles@earth.li> wrote:
>
> On Thu, Apr 20, 2023 at 06:43:06PM -0700, Saravana Kannan wrote:
> > On Thu, Apr 20, 2023 at 12:12 PM Jonathan McDowell <noodles@earth.li> wrote:
> > > On Sun, Apr 16, 2023 at 01:24:21AM +0100, Andre Przywara wrote:
> > > > On Sat, 15 Apr 2023 18:46:03 +0100
> > > > Jonathan McDowell <noodles@earth.li> wrote:
> > > >
> > > > > The C.H.I.P has an rtl8723bs device with the bluetooth interface hooked
> > > > > up on UART3. Support for this didn't exist in mainline when the DTS was
> > > > > initially added, but it does now, so enable it.
> > > > >
> > > > > Signed-off-by: Jonathan McDowell <noodles@earth.li>
> > > > > ---
> > > > >  arch/arm/boot/dts/sun5i-r8-chip.dts | 4 ++++
> > > > >  1 file changed, 4 insertions(+)
> > > > >
> > > > > diff --git a/arch/arm/boot/dts/sun5i-r8-chip.dts b/arch/arm/boot/dts/sun5i-r8-chip.dts
> > > > > index fd37bd1f3920..4d72a181d8aa 100644
> > > > > --- a/arch/arm/boot/dts/sun5i-r8-chip.dts
> > > > > +++ b/arch/arm/boot/dts/sun5i-r8-chip.dts
> > > > > @@ -255,6 +255,10 @@ &uart3 {
> > > > >     pinctrl-0 = <&uart3_pg_pins>,
> > > > >                 <&uart3_cts_rts_pg_pins>;
> > > > >     status = "okay";
> > > > > +
> > > > > +   bluetooth {
> > > > > +           compatible = "realtek,rtl8723bs-bt";
> > > > > +   }
> > > >
> > > > As the kernel test robot already pointed out, there is a semicolon
> > > > missing here.
> > > > Otherwise looks good (dt-validate passes), but don't know if there are
> > > > any wakeup GPIOs connected (can't seem to find a schematic?).
> > >
> > > So there are wakeups, but if I add:
> > >
> > >         device-wake-gpios = <&axp_gpio 3 GPIO_ACTIVE_LOW>;
> > >         host-wake-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
> > >
> > > then some odd sort of dependency issue happens where the serial port
> > > load is deferred waiting for the GPIO to appear, and then the device
> > > doesn't work.
> >
> > When you say your device doesn't work, are you saying it never probes?

Read your whole email and it's a strange issue. Also, going forward to
avoid confusion, only reply to questions with respect to 6.3-rc7.

> The bluetooth device (realtek,rtl8723bs-bt) never appears, apparently
> because the UART it's attached to never loads - it doesn't even try to
> load the firmware.
>
> > <debugfs>/devices_deferred should tell you what devices have deferred and why.
>
> root@chip:~# cat /sys/kernel/debug/devices_deferred
> serial0-0

Do you see this in 6.3-rc7 too?

> > > Error in dmesg is:
> > >
> > > serial serial0-0: deferred probe pending
> > >
> > > on 6.3-rc and on 6.1 I get:
> > >
> > > dw-apb-uart 1c28c00.serial: Failed to create device link (0x180) with axp20x-gpio
> >
> > This error message doesn't block anything. So I don't think this is
> > the cause of your blocking issue. But I still want to understand why
> > this error message is showing up.
> >
> > > I'm not clear why it's trying to link the serial port to the GPIO; it
> > > seems that it should be the bluetooth device that depends on both the
> > > UART and the GPIO,
> >
> > A fix for the device link error message went in on v6.3-rc3. Is that
> > the 6.3 version you tested this on?
>
> I originally tried on 6.1.21, which is where I got the "Failed to create
> device link" message. I then moved to 6.3-rc7 as I saw there had been
> further changes recently. There I just get the:
>
> serial serial0-0: deferred probe pending

If the deferral is related to fw_devlink, you should see the reason
for deferring in the devices_deferred file. So I don't think the issue
is related to fw_devlink.

> message.
>
> > Also, I tried looking into the UART driver
> > (drivers/tty/serial/8250/8250_dw.c) but it wasn't clear how it ends up
> > populating the bluetooth serial device. If you can point that out,
> > that'd be helpful (assuming 6.3-rc3 still shows that error message).
>
> I have the following in my device tree:
>
> &uart3 {
>         pinctrl-names = "default";
>         pinctrl-0 = <&uart3_pg_pins>,
>                     <&uart3_cts_rts_pg_pins>;
>         status = "okay";
>
>         bluetooth {
>                 compatible = "realtek,rtl8723bs-bt";
>                 device-wake-gpios = <&axp_gpio 3 GPIO_ACTIVE_LOW>;
>                 host-wake-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
>         };
> };
>
> uart3 is a snps,dw-apb-uart, defined in arch/arm/boot/dts/sun5i.dtsi
>
> The UART and AXP209 device drivers are compiled into the kernel:
>
> CONFIG_PINCTRL_AXP209=y
> CONFIG_SERIAL_8250=y
> CONFIG_SERIAL_8250_DW=y
>
> The bluetooth bits are modules (btrtl, hci_uart).
>
> If I remove the device-wake-gpios line then the Bluetooth device works
> fine, and /sys/kernel/debug/devices_deferred is empty.
>
> Somehow it seems like the GPIO is being parsed as a dependency for the
> serial port, even though the serial port + GPIO are both dependencies
> for the bluetooth device.

I'm fairly sure that fw_devlink isn't causing that. Because even
without bluetooth, fw_devlink doesn't consider any suppliers listed in
child DT nodes as mandatory suppliers. That has been the case since
the beginning.

> Even with that, given both are built-in I
> don't understand why the serial port never completes setup.

My guess is that the driver itself has some bug that's sensitive to
device probe order even though it shouldn't.

Can you add #define DEBUG 1 to the top of drivers/base/core.c and
share the boot log? I can try and help debug it.

-Saravana

> > > and that the GPIO is actually optional so shouldn't
> > > hold up loading, but I can't see how that should be represented.
> >
> > Optional dependencies should get ignored after the default
> > deferred_probe_timeout runs out and the supplier driver hasn't been
> > loaded yet.
>
> When I say it's optional I mean if it's not listed everything works
> fine, but I don't believe there's anyway to express that in the DTS.
> It's certainly not required for the serial port, just the bluetooth
> device.
>
> J.
>
> --
> Web [                     Don't be a stranger.                     ]
> site: https:// [                                          ]      Made by
> www.earth.li/~noodles/  [                      ]         HuggieTag 0.0.24
Jonathan McDowell April 24, 2023, 5:34 p.m. UTC | #3
On Fri, Apr 21, 2023 at 03:45:52PM -0700, Saravana Kannan wrote:
> On Fri, Apr 21, 2023 at 1:28 AM Jonathan McDowell <noodles@earth.li> wrote:
> >
> > On Thu, Apr 20, 2023 at 06:43:06PM -0700, Saravana Kannan wrote:
> > > On Thu, Apr 20, 2023 at 12:12 PM Jonathan McDowell <noodles@earth.li> wrote:
> > > > On Sun, Apr 16, 2023 at 01:24:21AM +0100, Andre Przywara wrote:
> > > > > On Sat, 15 Apr 2023 18:46:03 +0100
> > > > > Jonathan McDowell <noodles@earth.li> wrote:
> > > > >
> > > > > > The C.H.I.P has an rtl8723bs device with the bluetooth interface hooked
> > > > > > up on UART3. Support for this didn't exist in mainline when the DTS was
> > > > > > initially added, but it does now, so enable it.
> > > > > >
> > > > > > Signed-off-by: Jonathan McDowell <noodles@earth.li>
> > > > > > ---
> > > > > >  arch/arm/boot/dts/sun5i-r8-chip.dts | 4 ++++
> > > > > >  1 file changed, 4 insertions(+)
> > > > > >
> > > > > > diff --git a/arch/arm/boot/dts/sun5i-r8-chip.dts b/arch/arm/boot/dts/sun5i-r8-chip.dts
> > > > > > index fd37bd1f3920..4d72a181d8aa 100644
> > > > > > --- a/arch/arm/boot/dts/sun5i-r8-chip.dts
> > > > > > +++ b/arch/arm/boot/dts/sun5i-r8-chip.dts
> > > > > > @@ -255,6 +255,10 @@ &uart3 {
> > > > > >     pinctrl-0 = <&uart3_pg_pins>,
> > > > > >                 <&uart3_cts_rts_pg_pins>;
> > > > > >     status = "okay";
> > > > > > +
> > > > > > +   bluetooth {
> > > > > > +           compatible = "realtek,rtl8723bs-bt";
> > > > > > +   }
> > > > >
> > > > > As the kernel test robot already pointed out, there is a semicolon
> > > > > missing here.
> > > > > Otherwise looks good (dt-validate passes), but don't know if there are
> > > > > any wakeup GPIOs connected (can't seem to find a schematic?).
> > > >
> > > > So there are wakeups, but if I add:
> > > >
> > > >         device-wake-gpios = <&axp_gpio 3 GPIO_ACTIVE_LOW>;
> > > >         host-wake-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
> > > >
> > > > then some odd sort of dependency issue happens where the serial port
> > > > load is deferred waiting for the GPIO to appear, and then the device
> > > > doesn't work.
> > >
> > > When you say your device doesn't work, are you saying it never probes?
> 
> Read your whole email and it's a strange issue. Also, going forward to
> avoid confusion, only reply to questions with respect to 6.3-rc7.

Just to be clear, in my initial mail I referred to 6.1.21 as that's
where I started, but in my reply to you all output was quoted from
6.3-rc7. 6.3 has been released since, so all details below are based on
that.

> > The bluetooth device (realtek,rtl8723bs-bt) never appears, apparently
> > because the UART it's attached to never loads - it doesn't even try to
> > load the firmware.
> >
> > > <debugfs>/devices_deferred should tell you what devices have deferred and why.
> >
> > root@chip:~# cat /sys/kernel/debug/devices_deferred
> > serial0-0
> 
> Do you see this in 6.3-rc7 too?

That was under 6.3-rc7. I see it on 6.3 too:

root@chip:~# cat /sys/kernel/debug/devices_deferred
serial0-0

Without the device-wake-gpios line in the device tree it's empty.

> > > > Error in dmesg is:
> > > >
> > > > serial serial0-0: deferred probe pending
> > > >
> > > > on 6.3-rc and on 6.1 I get:
> > > >
> > > > dw-apb-uart 1c28c00.serial: Failed to create device link (0x180) with axp20x-gpio
> > >
> > > This error message doesn't block anything. So I don't think this is
> > > the cause of your blocking issue. But I still want to understand why
> > > this error message is showing up.
> > >
> > > > I'm not clear why it's trying to link the serial port to the GPIO; it
> > > > seems that it should be the bluetooth device that depends on both the
> > > > UART and the GPIO,
> > >
> > > A fix for the device link error message went in on v6.3-rc3. Is that
> > > the 6.3 version you tested this on?
> >
> > I originally tried on 6.1.21, which is where I got the "Failed to create
> > device link" message. I then moved to 6.3-rc7 as I saw there had been
> > further changes recently. There I just get the:
> >
> > serial serial0-0: deferred probe pending
> 
> If the deferral is related to fw_devlink, you should see the reason
> for deferring in the devices_deferred file. So I don't think the issue
> is related to fw_devlink.

Ok.

> > message.
> >
> > > Also, I tried looking into the UART driver
> > > (drivers/tty/serial/8250/8250_dw.c) but it wasn't clear how it ends up
> > > populating the bluetooth serial device. If you can point that out,
> > > that'd be helpful (assuming 6.3-rc3 still shows that error message).
> >
> > I have the following in my device tree:
> >
> > &uart3 {
> >         pinctrl-names = "default";
> >         pinctrl-0 = <&uart3_pg_pins>,
> >                     <&uart3_cts_rts_pg_pins>;
> >         status = "okay";
> >
> >         bluetooth {
> >                 compatible = "realtek,rtl8723bs-bt";
> >                 device-wake-gpios = <&axp_gpio 3 GPIO_ACTIVE_LOW>;
> >                 host-wake-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
> >         };
> > };
> >
> > uart3 is a snps,dw-apb-uart, defined in arch/arm/boot/dts/sun5i.dtsi
> >
> > The UART and AXP209 device drivers are compiled into the kernel:
> >
> > CONFIG_PINCTRL_AXP209=y
> > CONFIG_SERIAL_8250=y
> > CONFIG_SERIAL_8250_DW=y
> >
> > The bluetooth bits are modules (btrtl, hci_uart).
> >
> > If I remove the device-wake-gpios line then the Bluetooth device works
> > fine, and /sys/kernel/debug/devices_deferred is empty.
> >
> > Somehow it seems like the GPIO is being parsed as a dependency for the
> > serial port, even though the serial port + GPIO are both dependencies
> > for the bluetooth device.
> 
> I'm fairly sure that fw_devlink isn't causing that. Because even
> without bluetooth, fw_devlink doesn't consider any suppliers listed in
> child DT nodes as mandatory suppliers. That has been the case since
> the beginning.

Ok, I just got confused with the 6.1 message about the device link and
thought that might be the rough area.

> > Even with that, given both are built-in I
> > don't understand why the serial port never completes setup.
> 
> My guess is that the driver itself has some bug that's sensitive to
> device probe order even though it shouldn't.
> 
> Can you add #define DEBUG 1 to the top of drivers/base/core.c and
> share the boot log? I can try and help debug it.

Thanks for any input you're able to provide. dmesg from 6.3 with a
failure to complete the probe:

https://the.earth.li/~noodles/chip-bluetooth/6.3-not-working

and just for completeness, without the device-wake-gpios line:

https://the.earth.li/~noodles/chip-bluetooth/6.3-working

J.
Jonathan McDowell May 10, 2023, 11:34 a.m. UTC | #4
On Mon, May 01, 2023 at 02:12:05PM -0700, Saravana Kannan wrote:
> On Mon, Apr 24, 2023 at 10:34 AM Jonathan McDowell <noodles@earth.li> wrote:
> >
> > On Fri, Apr 21, 2023 at 03:45:52PM -0700, Saravana Kannan wrote:
> > > On Fri, Apr 21, 2023 at 1:28 AM Jonathan McDowell <noodles@earth.li> wrote:
> > > >
> > > > On Thu, Apr 20, 2023 at 06:43:06PM -0700, Saravana Kannan wrote:
> > > > > On Thu, Apr 20, 2023 at 12:12 PM Jonathan McDowell <noodles@earth.li> wrote:
> > > > > > On Sun, Apr 16, 2023 at 01:24:21AM +0100, Andre Przywara wrote:
> > > > > > > On Sat, 15 Apr 2023 18:46:03 +0100
> > > > > > > Jonathan McDowell <noodles@earth.li> wrote:
> > > > > > >
> > > > > > > > The C.H.I.P has an rtl8723bs device with the bluetooth interface hooked
> > > > > > > > up on UART3. Support for this didn't exist in mainline when the DTS was
> > > > > > > > initially added, but it does now, so enable it.
> > > > > > > >
> > > > > > > > Signed-off-by: Jonathan McDowell <noodles@earth.li>
> > > > > > > > ---
> > > > > > > >  arch/arm/boot/dts/sun5i-r8-chip.dts | 4 ++++
> > > > > > > >  1 file changed, 4 insertions(+)
> > > > > > > >
> > > > > > > > diff --git a/arch/arm/boot/dts/sun5i-r8-chip.dts b/arch/arm/boot/dts/sun5i-r8-chip.dts
> > > > > > > > index fd37bd1f3920..4d72a181d8aa 100644
> > > > > > > > --- a/arch/arm/boot/dts/sun5i-r8-chip.dts
> > > > > > > > +++ b/arch/arm/boot/dts/sun5i-r8-chip.dts
> > > > > > > > @@ -255,6 +255,10 @@ &uart3 {
> > > > > > > >     pinctrl-0 = <&uart3_pg_pins>,
> > > > > > > >                 <&uart3_cts_rts_pg_pins>;
> > > > > > > >     status = "okay";
> > > > > > > > +
> > > > > > > > +   bluetooth {
> > > > > > > > +           compatible = "realtek,rtl8723bs-bt";
> > > > > > > > +   }
> > > > > > >
> > > > > > > As the kernel test robot already pointed out, there is a semicolon
> > > > > > > missing here.
> > > > > > > Otherwise looks good (dt-validate passes), but don't know if there are
> > > > > > > any wakeup GPIOs connected (can't seem to find a schematic?).
> > > > > >
> > > > > > So there are wakeups, but if I add:
> > > > > >
> > > > > >         device-wake-gpios = <&axp_gpio 3 GPIO_ACTIVE_LOW>;
> > > > > >         host-wake-gpios = <&pio 1 3 GPIO_ACTIVE_HIGH>; /* PB3 */
> > > > > >
> > > > > > then some odd sort of dependency issue happens where the serial port
> > > > > > load is deferred waiting for the GPIO to appear, and then the device
> > > > > > doesn't work.
> > > > >
> > > > > When you say your device doesn't work, are you saying it never probes?
> > >
> > > Read your whole email and it's a strange issue. Also, going forward to
> > > avoid confusion, only reply to questions with respect to 6.3-rc7.
> 
> Sorry it took a while to respond. Life got busy.

No problem, I appreciate you looking into this.

> > Just to be clear, in my initial mail I referred to 6.1.21 as that's
> > where I started, but in my reply to you all output was quoted from
> > 6.3-rc7. 6.3 has been released since, so all details below are based on
> > that.
> >
> > > > The bluetooth device (realtek,rtl8723bs-bt) never appears, apparently
> > > > because the UART it's attached to never loads - it doesn't even try to
> > > > load the firmware.
> > > >
> > > > > <debugfs>/devices_deferred should tell you what devices have deferred and why.
> > > >
> > > > root@chip:~# cat /sys/kernel/debug/devices_deferred
> > > > serial0-0
> > >
> > > Do you see this in 6.3-rc7 too?
> >
> > That was under 6.3-rc7. I see it on 6.3 too:
> >
> > root@chip:~# cat /sys/kernel/debug/devices_deferred
> > serial0-0
> 
> I somehow didn't connect the dots earlier... but serial0-0 is NOT the
> uart/serial device. It's the child device of serial0 and in this case,
> it's the bluetooth device.
> 
> So adding those gpios in DT is not breaking serial. It's just
> preventing the BT device from probing.

Aaaaah.

> Looking at the logs in the non-working case:
> 
> [    0.715083] 1c28c00.serial: ttyS1 at MMIO 0x1c28c00 (irq = 53,
> base_baud = 1500000) is a U6_16550A
> [    0.724132] device: 'serial0': device_add
> 
> I don't know why all of the ttySx are showing up as serial0, but this
> is the serial port. As you can see 1c28c00 is already probing.
> 
> [    0.724228] device: 'serial0-0': device_add
> 
> This is the child devices getting populated. In this case this is the BT device.
> 
> [    0.724311] device: 'platform:1c20800.pinctrl--serial:serial0-0': device_add
> 
> I can tell it's the BT device because we see a device link being
> created between pinctrl and serial:serial0-0. So it's a device sitting
> on the serial bus.
> 
> [    0.724378] devices_kset: Moving serial0-0 to end of list
> [    0.724390] serial serial0-0: Linked as a consumer to 1c20800.pinctrl
> [    0.724401] /soc/serial@1c28c00/bluetooth Dropping the fwnode link
> to /soc/pinctrl@1c20800
> 
> And the fwnode like that was converted to device link clearly shows
> that the serial0-0 corresponds to the bluetooth node.
> 
> [    0.724441] serial serial0: tty port ttyS1 registered
> 
> Serial port works.
> 
> >
> > Without the device-wake-gpios line in the device tree it's empty.
> 
> I think the issue is at the BT driver level or some other framework.
> 
> Add a print at the start of the BT driver to see if the probe() is
> actually getting called. I'm guessing it is and it's returning an
> error from within.
> 
> If you don't see that print, then debug the really_probe() function to
> see how far within it the BT device goes through before it errors out.
> It's possible pinctrl_bind_pins() in really_probe() fails for the BT
> device because of how the GPIO pins are configured in your DT.

Thank you! That was exactly the pointer I needed to go and find the
actual issue, which is a real facepalm moment. The AXP209 driver does
not have support for GPIO3 (which is in a different register and needs a
bunch of special casing). So the Bluetooth driver tries to request it
and gets failures, so can't complete the probe.

I've added support to the pinctrl-axp209 driver for GPIO3 and everything
is working just fine now. I'll get that cleaned up and a v2 patch set
submitted. Thanks for all your help.

J.
diff mbox series

Patch

diff --git a/arch/arm/boot/dts/sun5i-r8-chip.dts b/arch/arm/boot/dts/sun5i-r8-chip.dts
index fd37bd1f3920..4d72a181d8aa 100644
--- a/arch/arm/boot/dts/sun5i-r8-chip.dts
+++ b/arch/arm/boot/dts/sun5i-r8-chip.dts
@@ -255,6 +255,10 @@  &uart3 {
 	pinctrl-0 = <&uart3_pg_pins>,
 		    <&uart3_cts_rts_pg_pins>;
 	status = "okay";
+
+	bluetooth {
+		compatible = "realtek,rtl8723bs-bt";
+	}
 };
 
 &usb_otg {