16-bit transfer via SPI with DMA TMS320C6745 yields overlapping output

I have a custom board with a TMS320C6745 connected to a ADS7953 ADC. I would like to utilize the full capability of the ADC so I am using DMA.

The problem I am having is that the DMA controller isn't correctly incrementing its pointer in memory. Though it should be incremented by 2, it is only incremented by 1 and thus the data written to the SPI port overlaps.

I have looked at these related threads to no avail:

http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/168604.aspx (Copied this code into Spi_edma, recompiled driver, recompiled test program, still broken)

http://e2e.ti.com/support/embedded/bios/f/355/t/89303.aspx (Tried this, still no)

http://e2e.ti.com/support/embedded/bios/f/355/t/170382.aspx (This too, no)

http://e2e.ti.com/support/embedded/bios/f/355/t/130781.aspx (This neither)

I'm out of ideas. Perhaps someone can attach a working copy of the source code and the compiled libraries. I'm not sure where the problem is at this point.

void SpiUserInit()
{
spiParams = Spi_PARAMS;

spiParams.hwiNumber = 8;
spiParams.spiHWCfgData.intrLevel = FALSE;
spiParams.opMode = Spi_OpMode_DMAINTERRUPT;
//spiParams.opMode = Spi_OpMode_INTERRUPT;
//spiParams.opMode = Spi_OpMode_POLLED;

spiParams.outputClkFreq = 15000000; 
spiParams.loopbackEnabled = FALSE;
spiParams.edmaHandle = NULL;

spiParams.spiHWCfgData.configDatafmt[0].charLength = 16u;
spiParams.spiHWCfgData.configDatafmt[0].clkHigh = TRUE;
spiParams.spiHWCfgData.configDatafmt[0].lsbFirst = FALSE;
spiParams.spiHWCfgData.configDatafmt[0].oddParity = FALSE;
spiParams.spiHWCfgData.configDatafmt[0].parityEnable = FALSE;
spiParams.spiHWCfgData.configDatafmt[0].phaseIn = FALSE;
spiParams.spiHWCfgData.configDatafmt[0].waitEnable = FALSE;
spiParams.spiHWCfgData.configDatafmt[0].wDelay = 10;
spiParams.spiHWCfgData.intrLevel = TRUE;

spiParams.spiHWCfgData.waitDelay = TRUE;/**< True - enable format delay between 2 consecutive transfers ; */
spiParams.spiHWCfgData.pinOpModes = Spi_PinOpMode_SPISCS_4PIN;
spiParams.spiHWCfgData.delay.c2TDelay = 5; // < [IN] Chip-select-active-to-transmit-start-delay
spiParams.spiHWCfgData.delay.t2CDelay = 0; /**< [IN] Transmit-end-to-chip-select-inactive-delay */
//spiParams.spiHWCfgData.delay.t2EDelay = 0;/**< [IN] Transmit-data-finished-to-ENA-pin-inactive-time-out */
//spiParams.spiHWCfgData.delay.c2EDelay = 0;/**< [IN] Chip-select-active-to-ENA-signal-active-time-out */

Spi_init();
}

/* Buffer alignment is required when working in DMA Mode */
#pragma DATA_ALIGN(loopWrite, 128);
Uint8 loopWrite[ADC_BUF_SIZE];

/* Buffer alignment is required when working in DMA Mode */
#pragma DATA_ALIGN(loopRead, 128);
Uint8 loopRead[ADC_BUF_SIZE];

void init_adc()
{
GIO_Attrs gioAttrs = GIO_ATTRS;

Spi_ChanParams chanParams;

//if the edma support is required then we need to configure edma
EDMA3_DRV_Result edmaResult = 0;

if (NULL == hEdma)
{
edmaResult = edma3init();
if (EDMA3_DRV_SOK != edmaResult)
{
//Error in configuring the edma driver
LOG_printf(&trace,"\r\nEDMA3 : edma3init() failed\r\n");
}
else
{
LOG_printf(&trace,"\r\nEDMA3 : edma3init() passed\r\n");
}
}
chanParams.hEdma = hEdma;

//create SPI channel for transmission

spiHandle = GIO_create("/Spi1",IOM_INOUT,NULL,&chanParams,&gioAttrs);

if (spiHandle == NULL)
{
LOG_printf(&trace,"\r\n SPI Driver Handle creation Failed ");
}

}

void adc_read(int channel, Uint16 *buf, int count)
{

Spi_DataParam dataparam;
size_t size = 0;

/* clear the input and output buffers */
memset(loopWrite, 0x00, sizeof(loopWrite));
memset(loopRead , 0x00, sizeof(loopRead));

/* clear the spi params data structure */
memset(&dataparam,0x00, sizeof(Spi_DataParam));

//MANUAL MODE COMMAND for NEXT channel
int cmd = MODE_MANUAL | (channel << 7);

//Set data to be written
int i;
for(i = 0; i < count*2; i++)
{
loopWrite[i++] = (Uint8)cmd;
loopWrite[i] = (Uint8)(cmd >> 8);

}

dataparam.bufLen = 2*count;
dataparam.inBuffer = &loopRead[0];
dataparam.outBuffer = &loopWrite[0];
//CS needs to be toggled after every 16-bit word. The input is sampled at the CS signal's falling edge.
//dataparam.flags = Spi_CSHOLD; 
dataparam.dataFormat = Spi_DataFormat_0;
dataparam.chipSelect = 0x01;
size = dataparam.bufLen;

// write command
GIO_write(spiHandle, &dataparam, &size);

//... do something with the data

}