AM3352 custom board mmc boot problem using SDK v07.00

Hi Dimitar,

Can you describe what the problem is?

Hi,

What is the filesystem you are using on the root partition of your SD card? Check whether you have kernel support enabled for the particular file system.

Best regards,
Miroslav

Hi Miroslav,

i use ext4 FS , and yes ext4 is built into kernel.

grep EXT4 .config
CONFIG_EXT4_FS=y

u-boot environment is default, so i think this is mmc driver SD Card detection bug.

When i try to list sd contents in u-boot it works fine . I can see files and partitions.

~Best

Dimitar, I can't see the pinmuxing for the MMC pins in your .dts file. Did you do it inside am33xx.dtsi?

Best regards,
Miroslav

I can see you are using the MMC controller's SDCD pin. Please try using a GPIO and specify the GPIO pin inside the .dts file using:

cd-gpios = <&gpio ## #>;

More information inside <linux_kernel_dir>/Documentation/devicetree/bindings/mmc/mmc.txt

Best regards,
Miroslav

Hi Miroslav,

i just made changes you talking about.

I add following lines to my dts file :

mmc cd pin :

mmc1_pins: pinmux_mmc1_pins {
pinctrl-single,pins = <
0x160 (PIN_INPUT | MUX_MODE7) /* spi0_cs1.gpio0_6 */
>;
};

and 

&mmc1 {
status = "okay";
vmmc-supply = <&vmmc_reg>;
bus-width = <4>;
pinctrl-names = "default";
pinctrl-0 = <&mmc1_pins>;
cd-gpios = <&gpio0 6 GPIO_ACTIVE_HIGH>;
};

This cause kernel panic @omap4_rng_init

Please see log here :

http://pastebin.com/gySYTZdn

Best Regards,

Dimtiar

Try to disable the random number generator for now, in order to at least see if the MMC card would be successfully detected by the kernel.

Best regards,
Miroslav

When Random HWGen is disabled board boots and hangs at same place. 

I made some tests with 3.11.0 and board boots fine. So i think this must be some kernel config  problem.  When  I run diff on configs  there is no significant difference.

So i am waiting for further suggestions.

Thanks in advance

Dimitar

~Best 

Dimitar Gamishev said:

When Random HWGen is disabled board boots and hangs at same place. 

Do you mean "Waiting for root device /dev/mmcblk0p2..." ?

Dimitar Gamishev said:

I made some tests with 3.11.0 and board boots fine.

Are you using the same device tree files in both cases?

What exactly are the differences between the kernel configurations?

Best regards,
Miroslav

Hi Miroslav,

sorry for delay.

There is no significant difference between configs. I think the problem is in VDD regulator, in our design we do not use PMU. I think omap_hsmmc fails to load because of this :

[    2.114389] omap_hsmmc 48060000.mmc: unable to get vmmc regulator -517

[    2.135340] platform 48060000.mmc: Driver omap_hsmmc requests probe deferral

Is there a way to disable PMU at all ?

~Best