Cppi_Desc union wrong?

Sebastian D.

Hi,

there seems to be an error in the definition of Cppi_Desc in cppi_desc.h.

/**
* @brief CPPI descriptor
*/
typedef union {
    /** Host descriptor */
    Cppi_HostDesc       *ptrHostDesc;
    /** Monolithic descriptor */
    Cppi_MonolithicDesc *ptrMonoDesc;
}Cppi_Desc;

This leads to completely wrong Instructions like:

Cppi_Desc *pCppiDesc = Qmss_queuePop (hFDQ));
pCppiDesc->ptrHostDesc->buffLen = pCppiDesc->ptrHostDesc->origBufferLen; (!!!wrong!!!)

(One level of indirection too much)

When I look at, how Cppi_desc is used in the Cppi LLD, I think it should be:

/**
* @brief CPPI descriptor
*/
typedef union {
    /** Host descriptor */
    Cppi_HostDesc       hostDesc;
    /** Monolithic descriptor */
    Cppi_MonolithicDesc monoDesc;
}Cppi_Desc;

So I could do thinks like that:

Cppi_Desc *pCppiDesc = Qmss_queuePop (hFDQ));
pCppiDesc->hostDesc.buffLen = pCppiDesc->hostDesc.origBufferLen;

over 12 years ago

0 Tom Kopriva over 12 years ago

TI__Mastermind 20480 points

Hi Sebastian,

Not sure where this code is from? Which product is this?

0 Sebastian D. over 12 years ago in reply to Tom Kopriva

Intellectual 265 points

Hi,

I originally posted this thread in the C6000 Multicore forum. It was moved here by a moderator.

This code is part of the Platform Development Kit (PDK) of the C6670 DSP. The CPPI and QMSS Low Level Driver (LLD) handle operations on the Multicore Navigator, which I think is only available for C66xx devices.

0 db_woodall over 12 years ago in reply to Sebastian D.

TI__Mastermind 21025 points

Hi Sebastian,

I believe this is more a matter of style than error. I personally prefer the idea of a union of structs vs. a union of pointers, but to make the change at this point would require a rewrite of the CPPI LLD and would impact every program currently using it. This makes the change prohibitive. You could create your own union of structs and use it within your program.

-dave

Processors

Processors forum

Cppi_Desc union wrong?