On 2019-02-22 19:47, David Summers wrote: > The Problem: > > On ASUS Tinker Board S, when booting from the eMMC, and there is no > card sd slot, then there are constant errors. > > Cause: > > Thanks must go to Robin Murphy @ ARM for idenifying the problem. The > rk808 on the Tinker Board and Tinker Board S has many regulators, one > vccio_sd powers the IO for the sd card. Unfortunatly this is also used > in the card detect. Now when no card is install, the regulator is > powered down. This means that the card detect floats, and this means > random card detection. > > The Solution: > > Make sure that the sd IO is always powered, this means card detection > is always active, which is what should be done on a board with an sd > slot, which both the Tinker Board and Tinker Board S are. Hence change > is made to the .dtsi which takes effect on all Tinker Boards as > required. > > The change also adds "regulator-boot-on" the Tinker Board boot from > uboot, and the sd card is always one option. Hence the IO must be > powered in uboot, and so setting this flag. > > Also removed is "disable-wp" the micro sd card which are used have no > write protection, so the concept doesn't mean anything, and the > Tinker Boards work without this. Hence it is removed to simply. > > This change came from ArchLinux Arm, but we note it is the fix also > used by Armbian: > > https://github.com/Miouyouyou/RockMyy/blob/master/patches/kernel/v5.0/DTS/0016-ARM-DTSI-rk3288-tinker-Setting-up-the-SD-regulators.patch > > Signed-off-by: David Summers <beagleboard@xxxxxxxxxxxxxxxxxxx> > --- > arch/arm/boot/dts/rk3288-tinker.dtsi | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/boot/dts/rk3288-tinker.dtsi b/arch/arm/boot/dts/rk3288-tinker.dtsi > index aa107ee41b8b..6b7e55085b0c 100644 > --- a/arch/arm/boot/dts/rk3288-tinker.dtsi > +++ b/arch/arm/boot/dts/rk3288-tinker.dtsi > @@ -254,6 +254,8 @@ > }; > > vccio_sd: LDO_REG5 { > + regulator-always-on; > + regulator-boot-on; > regulator-min-microvolt = <1800000>; > regulator-max-microvolt = <3300000>; > regulator-name = "vccio_sd"; > @@ -431,7 +433,6 @@ > cap-mmc-highspeed; > cap-sd-highspeed; > card-detect-delay = <200>; > - disable-wp; /* wp not hooked up */ I think disable-wp correctly describes that wp is not expected to work and should not be removed. >From comment in mmc_sd_get_ro(): "Some systems don't feature a write-protect pin and don't need one. E.g. because they only have micro-SD card slot. For those systems assume that the SD card is always read-write." Without disable-wp core will call dw_mci_get_ro() to get wp status. This patch also fixes reboot when booting from sd-card and having emmc zeroed out. Tested-by: Jonas Karlman <jonas@xxxxxxxxx> Regards, Jonas > pinctrl-names = "default"; > pinctrl-0 = <&sdmmc_clk &sdmmc_cmd &sdmmc_cd &sdmmc_bus4>; > status = "okay";
