C6670 SRIO Message passing method - Segmentation operation

Rajkumar

Which PDK are you using? It is in multicoreLoopback.c under static Int32 test_multicore (Srio_DrvHandle hSrioDrv).

Elush Shirazpour

Hi Elush Shirazpour

Thank you for your reply.

PDK I used is pdk_C6670_1_1_0_3.

Program : MulticoreLoopbackProject

We tried for the Packet transmission with size 4096  from core 0 to core 1 using the same project for our application purpose .

Our application needs maximum 4k transmission support with packet segmentation of 256 Bytes.

We done below steps for the same.

We set SRIO_MAX_MTU as 4096.

cfg.u.drvManagedCfg.txCfg.txMTU = 4096;

cfg.u.drvManagedCfg.rxCfg.rxMTU = 4096;

Srio_sockSend (srioSocket, hDrvBuffer, 4096, &to)

Bind with Segmap = 0x0; /*single segment */

Does it mean that single packet transmission with packet size 4096 without segmentation ?

Do we need to segment the packets in application level before give it to the SRIO driver ?

Looking forward for your valuable reply.

Thanks

Rajkumar

Rajkumar

The maximum packet size is 256 bytes so in order to send a packet of size 4096, you will need to do segmentation. 

Yes. You need to segment the packets in application level first before giving it to the SRIO driver.

Take a look at this past E2E for some answers on SRIO_MAX_MTU.

https://e2e.ti.com/support/dsp/c6000_multi-core_dsps/int-c66x_multi-core_dsps/f/513/t/161835.aspx?pi36454=1&Redirected=true

Elush Shirazpour

Dear Elush

Thank you very much for the reply.

Then I could not open the link that you shared .I am getting following error

Rajkumar

My mistake. Try this one.

http://e2e.ti.com/support/dsp/c6000_multi-core_dsps/f/639/p/199765/711981.aspx#711981

Elush

Hi Elush

Is it possible to send a host descriptor from Core to core  through SRIO in the below mentioned manner ?

Hostdesc1, Hostdesc2, Hostdesc3 . Each linked with data buffer set with  size 10Bytes.

then I linked descriptors using LinkNextBD API .

Hostdesc3->Hostdesc2->Hostdesc1

Finally I want to send Hostdesc3 in SRIO_Socksend().

Will I get a linear buffer at the receiver side ?

thanks

Rajkumar

Rajkumar

Since this is a different question, please post this on a new E2E forum so the correct people can see this and help you.

Elush

Hi elush,

Maximum I can send in Message passing method is 4096 Bytes.  I hope this is the maximum packet size which is supported by the message passing operation.

In the example program "Multicoreloopback project " in the pdk_C6670_1_1_0_3   , it was 256 Bytes transmission only with segmap field set as 0x0 .

I modified it to 4096 Bytes with segmap field set as 0x0. Successfully verified 4096 Bytes transmission at single stretch transmission using Socksend API.

1) Now my doubt is whether this 4096 Bytes transmitted as single segment or multi-segment.

2) Since it supports 4k then Why do I need segmentation ?

Please clarify..

Thanks
Rajkumar

Rajkumar

1) It is a multi-segment message.

2) That 4K represents the 16 multi-segment messages.

Elush