Hi,
On Mon, May 18, 2015 at 11:03 PM, Lawrence Yu <[email protected]> wrote: > Hi, > > > On Mon, May 18, 2015 at 8:01 PM, Chen-Yu Tsai <[email protected]> wrote: > >> Hi, >> >> On Mon, May 18, 2015 at 12:08 AM, Lawrence Y <[email protected]> wrote: >> > Hi, >> > >> > I'm not sure if it is my sdcard, my A31 hummingboard device, or >> something I >> > am doing wrong, but I've been trying to boot an A31 hummingbird from an >> > sdcard using the kernel from the sunxi-next branch at >> > >> > https://github.com/mripard/linux >> > 33da8d2 - Merge tag 'ib-mfd-regulator-v4.2' into sunxi-next >> > >> > and ran into a problem where the kernel would hang while waiting for the >> > root device /dev/mmcblk0p2 >> > >> > If I use the sun6i-a31-hummingbird.dtb built from the linux mainline the >> > sdcard will boot the root file system correctly, but if I use the >> > sun6i-a31-hummingbird.dtb from sunxi-next the kernel will hang while >> waiting >> > for /dev/mmcblk0p2. >> > >> > I ran a git bisect and narrowed down the commit that causes the problem >> I am >> > seeing to >> > >> > commit bab03561224baa536b98f1d137d2b6b5dd159763 >> > Date: Tue Mar 10 19:59:21 2015 +0800 >> > >> > ARM: dts: sun6i: hummingbird: Add AXP221 regulator nodes >> > >> > This patch adds the AXP221 regulators. Only the ones directly used >> > on the board are added. >> > >> > Please let me know if there is anything I can do to help fix this >> problem, >> > if it really is a problem. I have an A31 hummingbird available for >> testing. >> >> The latest commit you pointed to merges AXP221 support with regulators. >> The Hummingbird A31 dts was also updated with the new regulator nodes. >> >> Do you have AXP20X MFD and regulator support enabled? >> CONFIG_MFD_AXP20X and CONFIG_REGULATOR_AXP20X should be y. >> >> >> ChenYu >> > > I tested with the sunxi_defconfig and confirmed that > > CONFIG_INPUT_AXP20X_PEK=y > CONFIG_MFD_AXP20X=y > CONFIG_REGULATOR_AXP20X=y > > are set in the .config file by the sunxi_defconfig and was used when the > root file system on the mmc card is not detected during the boot. > > I did some more experimenting and found that if I change the vmmc-supply > for the mmc0 in the dts from vcc_3v0 to reg_vcc3v0 the root file system on > the sdcard will boot properly > > @@ -119,7 +119,7 @@ > &mmc0 { > pinctrl-names = "default"; > pinctrl-0 = <&mmc0_pins_a>, <&mmc0_cd_pin_hummingbird>; > - vmmc-supply = <&vcc_3v0>; > + vmmc-supply = <®_vcc3v0>; > bus-width = <4>; > cd-gpios = <&pio 0 8 GPIO_ACTIVE_HIGH>; /* PA8 */ > cd-inverted; > > I am going to try Han's suggestion of using the vcc_3v3 when I get a > chance to see if that makes it better. > > Lawrence > > I changed the vmmc-supply in the mmc0 dts section to be reg_vcc3v0 from vcc_3v0 and the tablet seems to boot to login from the sdcard consistently now. I'm not sure if the AXP20x module is being loaded or not from the hummingbird A31 dts file. I did a grep of the dmesg and there is no occurrence of the string AXP in the dmesg logs during boot. If the AXP20x module is not being loaded, maybe that could explain why the vcc_3v0 did not work for the mmc0 section? I also added some printk statements to the axp209 probe function that did not emit anything to the dmesg output, but I'm not sure if that is conclusive or not since I'm not sure if printk works in the probe. Maybe someone could suggest a better way to tell if the AXP221 support is being loaded? Thanks! Lawrence -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
