| Message ID | 20210128081411.1139971-1-eugen.hristev@microchip.com |
|---|---|
| State | Accepted |
| Commit | 5dc68b07e75d4695a554b60135d70f1847885bd2 |
| Delegated to: | Eugen Hristev |
| Headers | show |
| Series | ARM: dts: at91: sama7g5ek: enable pull-up for serial debug line | expand |
On 28.01.2021 10:14, Eugen Hristev wrote: > If the serial tx/rx are floating, it can happen that bogus characters > are detected on the line at boot time. This leads to U-boot accidentally > thinking someone pressed a key to stop autoboot, thus stopping booting process. > This can happen if the serial cable is not connected. There are hardware > pull-ups on the board connected to serial cable VBUS. > To solve this when the cable is not plugged, enable internal pull-ups as well > for the tx/rx lines. > > Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> > --- > arch/arm/dts/sama7g5ek.dts | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/dts/sama7g5ek.dts b/arch/arm/dts/sama7g5ek.dts > index ff9c9eb45c..3a4fdd38a5 100644 > --- a/arch/arm/dts/sama7g5ek.dts > +++ b/arch/arm/dts/sama7g5ek.dts > @@ -122,7 +122,7 @@ > pinctrl_flx3_default: flx3_default { > pinmux = <PIN_PD16__FLEXCOM3_IO0>, > <PIN_PD17__FLEXCOM3_IO1>; > - bias-disable; > + bias-pull-up; > }; > > pinctrl_sdmmc0_cmd_data_default: sdmmc0_cmd_data_default { > Applied to u-boot-atmel/master
diff --git a/arch/arm/dts/sama7g5ek.dts b/arch/arm/dts/sama7g5ek.dts index ff9c9eb45c..3a4fdd38a5 100644 --- a/arch/arm/dts/sama7g5ek.dts +++ b/arch/arm/dts/sama7g5ek.dts @@ -122,7 +122,7 @@ pinctrl_flx3_default: flx3_default { pinmux = <PIN_PD16__FLEXCOM3_IO0>, <PIN_PD17__FLEXCOM3_IO1>; - bias-disable; + bias-pull-up; }; pinctrl_sdmmc0_cmd_data_default: sdmmc0_cmd_data_default {
If the serial tx/rx are floating, it can happen that bogus characters are detected on the line at boot time. This leads to U-boot accidentally thinking someone pressed a key to stop autoboot, thus stopping booting process. This can happen if the serial cable is not connected. There are hardware pull-ups on the board connected to serial cable VBUS. To solve this when the cable is not plugged, enable internal pull-ups as well for the tx/rx lines. Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> --- arch/arm/dts/sama7g5ek.dts | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)