AM335x - Kernel 3.12.20 MUSB Problem

Hi Robert,

The kernel included in SDK v7 is 3.12.10 and you are using 3.12.20. Please check the commits between these two versions for any changes in the MUSB driver that may have caused a regression. Can you also try using the 3.12.10 kernel from the SDK?

Best regards,
Miroslav

Hi Miroslav,

I will take a look at the differences in the kernel versions.

In the SDK 6.0 there was a function in the board file called usb_musb_init().  How is this handled when moving to the dts files?

Just looking through the boot logs it doesn't appear like any of the DMA or musb calls found in the device tree are being called.  Any suggestions on the best way to debug the DTS file processing?

Thanks,

Robert

Robert,

Please send /proc/config.gz. I am wondering if you enabled CPPI in DMA Engine.

Please also provide the kernel boot dmesg log.

Hi Bin,

CPPI seems to be enabled, but maybe I missed something else.

Attached is config.gz and dmesg log.

Robert

Here is the dmesg.

Robert,

I don't see any issue in config.gz. But the mesg log does not have anything about MUSB, so I guess the dts has issues.

- Is this on TI EVM or your custom board? Please provide all AM335x related dts files you used.

- Please provide the whole serial console boot log from the beginning of u-boot.

- to make the debug simple for compare, please use omap2plus_defconfig to build the zImage, and don't put musb_hdrc into the kernel.

Bin,

This is a custom board based on the TI EVM.  I can swap a SD card with the 6.0 SDK and everything works fine.  So I am confident it is not a hardware issue.

I've attached the dts, dtsi and a full dmesg log.  I have been comparing the dts/dtsi files with those found in the SDK 7.0.  I made a couple of patches based on comments you made from a previous post about the ctrl-mod address and order of the dma.

I am building with MACHINE=am335x-evm so I'm using tisdk_am335x-evm_defconfig as the basis.

Robert

Robert,

Have you installed all kernel modules into the sd card?

What happens if you do 'modprobe musb_am335x'? Then does 'lsmod' list any module loaded?

Bin,

Yes, I have the kernel modules on the sd card.  I can successfully insert musb_am335x doing a modprobe and see that it is loaded.  The only message I get in dmesg is

platform 47401300.usb-phy: Driver am335x-phy-driver requests probe deferral

I keep thinking it is something with the dts processing.  If it couldn't find the module then it should show an error in the boot log right?

On a working build (SDK 06) I can see the DMA then MUSB drivers being loaded after usbcore.

Robert

Robert,

That message tells the phy driver misses dependency so its probe is deferred. That causes MUSB drivers are not loaded. But I am wondering why this message does not show up in kernel boot log...

I will check the kernel code to see if I can find what the missing dependency could be. If I don't update by today, please expect something next week, since I will take time off in next two days.

Meanwhile, could you please try this SDK7.0 release which is based on 3.12.10? this is the one we officially support.

http://software-dl.ti.com/sitara_linux/esd/AM335xSDK/latest/exports/am335x-evm-sdk-src-07.00.00.00.tar.gz

Robert,

I guess I found the problem - dts issue: ctrl_mod name don't match in am33xx.dtsi and am335x.dts.

in your am33xx.dtsi Line 519: ctrl_mod: control@44e10000

in your am335x-evm.dts Line 325: control@44e10620

Is the ctrl_mod address supposed to be 44e10000 or 44e10620?

Here is only for naming, so the value does not matter as long as they match to each other in both dts files.

The value is changed from 44e10000 to 44e10620 in the latest kernel on arago.

Bin,

That fixed my problem.  Setting the ctrl_mod labels to match in both the dts and dtsi files and then loading the musb drivers.

Thanks for your help!

Robert