AM5728: DSP booted from MLO hangs on IPC startup

Pavel Azizov42

Part Number: AM5728

Hello

We have managed to boot applications to DSP and IPU from MLO and they do not crash after Linux starts.

Now we try to boot form MLO a DSP application which connects with Linux via IPC (an example from TI with GPIO and IPC GPIO_LedBlink_evmAM572x_c66xExampleProject_with_ipc.zip

taken here processors.wiki.ti.com/.../Linux_IPC_on_AM57xx

Now the DSP application hangs in IpcMgr_ipcStartup() procedure and app_host application in Linux does not connect to it.

What should we check / change in DSP application (maybe, change resource table, change something in cfg-file etc.)?

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

The software team have been notified. They will respond here.

0 Garrett Ding over 8 years ago in reply to Biser Gatchev-XID

TI__Mastermind 43296 points

Pavel,

The section 'Adding IPC to an Existing TI-RTOS Application on slave cores' in the same wiki below the GPIO_LedBlink example elaborates the required changes for adding IPC, please apply those changes accordingly to your project.

Regards,

Garrett

0 Pavel Azizov42 over 8 years ago in reply to Garrett Ding

Intellectual 300 points

Garrett,

We have applied the changes. More of that, we use example from TI wiki
processors.wiki.ti.com/.../GPIO_LedBlink_evmAM572x_c66xExampleProject_with_ipc.zip

Everything is OK when we load this example with remoteproc driver ("bind" command).
Application from HOST can connect to DSP via IPC.

But when we load the same DSP application via MLO before Linux startup, we cannot connect to DSP from Linux ("app_host" application).
DSP application hangs on IpcMgr_ipcStartup().

We assume this is somehow connected with late attach in Linux.

Regards,
Pavel

0 Garrett Ding over 8 years ago in reply to Pavel Azizov42

TI__Mastermind 43296 points

Pavel,

You probably already read the early boot/late attach wiki - processors.wiki.ti.com/.../Early_Boot_and_Late_Attach_in_Linux
Without this feature enabled, ipMgr_ipcStartup() will hang if you load a DSP application via MLO before Linux startup.

Regards, Garrett

0 Pavel Azizov42 over 8 years ago in reply to Garrett Ding

Intellectual 300 points

Garrett,

we have ported Early Boot/Late attach support to AM572x Linux SDK (both kernel and u-boot features).
But we still have the same issue: DSP application hangs on IpcMgr_ipcStartup().

Regards,
Pavel

0 Rex Chang over 8 years ago in reply to Pavel Azizov42

TI__Guru 50170 points

Hi, Pavel,

Please note that IpcMgr_ipcStartup() will block until Linux comes up and sets up IPC communication for that core. In early boot/late attach cases, it may be better to schedule this function to run at a later time than you normally would in regular loading cases, especially if there are other tasks you wish to run before Linux comes up and sets up the communication. This item (from Android late attach wiki, but still applicable to Linux) gives more information:

processors.wiki.ti.com/.../Early_Boot_and_Late_Attach

There are kernel patches in addition to u-boot patches needed for late-attach. In kernel 4.4, these patches can be found here in automotive branches. Have you ported any kernel patches for late-attach?

Late attach changes in kernel:

http://review.omapzoom.org/#/c/37716/

http://review.omapzoom.org/#/c/37717/

http://review.omapzoom.org/#/c/37718/

http://review.omapzoom.org/#/c/37719/

http://review.omapzoom.org/#/c/37720/

http://review.omapzoom.org/#/c/37721/

http://review.omapzoom.org/#/c/37722/

Bug fixes:

http://review.omapzoom.org/#/c/38275/

Reserve mem for IOMMU table for late-attach case: (kernel and u-boot changes)

http://review.omapzoom.org/#/q/topic:iommu-reserve-mem

Rex