Fastboot issue on the VAR-SOM Gingerbread OS.

Siva naga kishore Kampili

Other Parts Discussed in Thread: DM3730

Hi,

I am working on custom board(DM3730 ) which has Gingerbread (kernel-2.6.37) OS flashed. After the device is powered up, from the device i have connected the USB cable to the PC, adb commands are working fine. I have given adb reboot, then the system is rebooting, device is interrupted at U-boot to go into the fastboot. Here fastboot not working, but we can observe the log "fastboot initialised". from cutecom

I have removed the battery and reinsert the battery, push the power on button, at normal boot, if i have interrupted at U-boot to go into the fastboot, it is working fine. Fast boot is not working if iam rebooting the device by the adb reboot command.

Note : In the adb reboot scenario, battery is not removed.

My observation is, if the battery is reinserted, then the USB OTG is working fine, so fastboot also working without any issue. I am expecting USB-OTG reset can solve this problem. Is there any way to reset the USB-OTG in the adb reboot scenario? or Is there any way to solve this issue?

Kishore

over 10 years ago

0 Cvetolin Shulev-XID over 10 years ago

TI__Guru 65405 points

Hi Kishore,

The USB-OTG registers are not public and therefore I can not give you information about.
The other way to investigate the issue if you have no debugger or console is to change the adb reboot command with something else because I suspect the adb reboot command makes an warm reset instead of cold reset which does not init all clocks for some reason. I suggest you to the try the "adb shell fastboot reboot" command.

BR
Tsvetolin Shulev

0 Siva naga kishore Kampili over 10 years ago in reply to Cvetolin Shulev-XID

Intellectual 500 points

Hi Tsvetolin Shulev,

We are having adb reboot commands to reboot the system. I have tried the "adb shell reboot fastboot", it is not "adb shell fastboot reboot" command. With this command also behavior does not changed. Is there any other commands to reboot the system?

BR
Kishore

0 Cvetolin Shulev-XID over 10 years ago in reply to Siva naga kishore Kampili

TI__Guru 65405 points

Kishore,

I only could suppose two ways for searching for a solution because the issue does not appear with the boards which I have:
Software way - by adding or increasing the timeouts before reset_cpu(0) function in the ../u-boot/arch/arm/lib/reset.c file. Also add debug messages to by sure that this code has been executed.
Hardware way - by making a revision of the schematics of the power supply circuit and searching for some bigger then necessary capacities.

BR
Tsvetolin Shulev

0 Siva naga kishore Kampili over 10 years ago in reply to Cvetolin Shulev-XID

Intellectual 500 points

Hi Tsvetolin Shulev,

I am using VAR-SOM DM3730 board. The function do_reset() in file "../u-boot/arch/arm/lib/reset.c" is called, when the user give reset() command at U-boot, but not by the command "adb reboot fastboot" at Android boot. So what i am thinking is, increasing the timeouts before reset_cpu(0), will not give any clue to debug the issue.

BR
Kishore

0 Cvetolin Shulev-XID over 10 years ago in reply to Siva naga kishore Kampili

TI__Guru 65405 points

Kishore,

Check the fbt_handle_reboot function in file "../u-boot/common/cmd_fastboot.c" which calls the do_reset function. Also add debug messages on each step to localize where the system stuck. If the debug messages appears to the last stage of rebooting procedure I assume that the stuck is possible to appears during the early steps of the boot also.

BR
Tsvetolin Shulev

0 Siva naga kishore Kampili over 10 years ago in reply to Cvetolin Shulev-XID

Intellectual 500 points

Hi Tsvetolin ,

When kernel booted up USB-OTG is working in client mode, after system is reboots, at U-boot USB-OTG is not working. When the user issued the adb-reboot command, kernel reboot the system by the WARM RESET by the PRM_RSTCTRL.RST_GS soft reset. I changed the reset to Cold reset RST_DPLL3, so it is working fine.

Is there is any USB-OTG issue with the Global warm reset?

BR,
Kishore

0 Cvetolin Shulev-XID over 10 years ago in reply to Siva naga kishore Kampili

TI__Guru 65405 points

Hi Kishore,

I found some erratas which I recommend you to check whether they directly match to your issue.
Check advisory: 1.78, 1.39 and 1.107 at Silicon Errata:
www.ti.com/.../sprz319f.pdf

BR
Tsvetolin Shulev

0 Siva naga kishore Kampili over 10 years ago in reply to Cvetolin Shulev-XID

Intellectual 500 points

Hi Tsvetolin ,

Thanks. I will check the errata and update the status. In the meanwhile, i want to conform that, can we do PRM_RSTCTRL.RST_DPLL3 (cold reset) instead of the warm reset by PRM_RSTCTRL.RST_GS bit? Are there known issues if we go by the cold reset ?

BR,
Kishore

0 Siva naga kishore Kampili over 10 years ago in reply to Siva naga kishore Kampili

Intellectual 500 points

Hi Tsvetolin ,

I have tried errata advisory 1.107 workaround at U-boot after warm reset from the kernel, but USB OTG is not working with this workaround also at U-boot.

BR,
Kishore

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Fastboot issue on the VAR-SOM Gingerbread OS.