On Tue, 8 Sep 2015 17:49:08 +0300 Siarhei Siamashka siarhei.siamashka@gmail.com wrote:
The Forfun Q88DB tablet was unbootable since commit b6006baf9c2553543e3384983d23d95efbf24fa6 ("sunxi: Move all boards to the driver-model"). Appears that this is caused by the wrong serial console setup in the SPL. The serial console should use PG3/PG4 pins according to the FEX file.
Signed-off-by: Siarhei Siamashka siarhei.siamashka@gmail.com
configs/forfun_q88db_defconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
While this should be a correct fix, the reason why the tablet failed to boot is a bit unclear. Without the correct CONS_INDEX setup, we should just get the serial console routed to the nonexisting pins B19/B20, and this is expected to be harmless. Maybe the DM code in the main U-Boot binary can't initialize serial console properly if we have a mismatch between the settings in the dts file and the CONS_INDEX settings in the SPL?
Yes, as an experiment, pretending that the tablet has an A10S SoC (the same die as A13, but with more pins routed to the outside, including B19/B20) also "fixes" the boot issue:
index 24de86c..9254a42 100644 --- a/arch/arm/dts/sun5i-a13-forfun-q88db.dts +++ b/arch/arm/dts/sun5i-a13-forfun-q88db.dts @@ -7,14 +7,14 @@ */
/dts-v1/; -#include "sun5i-a13.dtsi" +#include "sun5i-a10s.dtsi"
/ { model = "Forfun Q88db"; compatible = "forfun,q88db", "allwinner,sun5i-a13";
aliases { - serial0 = &uart1; + serial0 = &uart0; };
chosen { @@ -22,8 +22,8 @@ }; };
-&uart1 { +&uart0 { pinctrl-names = "default"; - pinctrl-0 = <&uart1_pins_b>; + pinctrl-0 = <&uart0_pins_a>; status = "okay"; };
Is something broken in the sunxi DM serial code, so that it partially relies on the SPL configuring the UART pins properly?