On Fri, Dec 09, 2016 at 07:49:00PM +0800, Icenowy Zheng wrote: > > 2016年12月9日 下午4:07于 Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>写道： > > > > On Tue, Dec 06, 2016 at 04:08:38PM +0800, Icenowy Zheng wrote: > > > Some SDIO Wi-Fi chips (such as RTL8703AS) have a UART bluetooth, which > > > has a dedicated enable pin (PL8 in the reference design). > > > > > > Enable the pin in the same way as the WLAN enable pins. > > > > > > Tested on an A33 Q8 tablet with RTL8703AS. > > > > > > Signed-off-by: Icenowy Zheng <icenowy@xxxxxxxx> > > > --- > > > > > > This patch should be coupled with the uart1 node patch I send before: > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2016-December/471997.html > > > > > > For RTL8703AS, the rtl8723bs bluetooth code is used, which can be retrieve from: > > > https://github.com/lwfinger/rtl8723bs_bt > > > > > > arch/arm/boot/dts/sun8i-q8-common.dtsi | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/arch/arm/boot/dts/sun8i-q8-common.dtsi b/arch/arm/boot/dts/sun8i-q8-common.dtsi > > > index c676940..4aeb5bb 100644 > > > --- a/arch/arm/boot/dts/sun8i-q8-common.dtsi > > > +++ b/arch/arm/boot/dts/sun8i-q8-common.dtsi > > > @@ -88,7 +88,7 @@ > > > > > > &r_pio { > > > wifi_pwrseq_pin_q8: wifi_pwrseq_pin@0 { > > > - pins = "PL6", "PL7", "PL11"; > > > + pins = "PL6", "PL7", "PL8", "PL11"; > > > function = "gpio_in"; > > > bias-pull-up; > > > }; > > > > There's several things wrong here. The first one is that you rely > > solely on the pinctrl state to maintain a reset line. This is very > > fragile (especially since the GPIO pinctrl state are likely to go away > > at some point), but it also means that if your driver wants to recover > > from that situation at some point, it won't work. > > > > The other one is that the bluetooth and wifi chips are two devices in > > linux, and you assign that pin to the wrong device (wifi). > > > > rfkill-gpio is made just for that, so please use it. > > The GPIO is not for the radio, but for the full Bluetooth part. I know. > If it's set to 0, then the bluetooth part will reset, and the > hciattach will fail. Both rfkill-gpio and rfkill-regulator will shutdown when called (either by poking the reset pin or shutting down the regulator), so that definitely seems like an expected behavior to put the device in reset. > The BSP uses this as a rfkill, and the result is that the bluetooth > on/off switch do not work properly. Then rfkill needs fixing, but working around it by hoping that the core will probe an entirely different device, and enforcing a default that the rest of the kernel might or might not change is both fragile and wrong. Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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