spi_async data wrong in linux!!

yongleili717 — Fri, 12 Jul 2019 03:38:33 GMT

Hello, our IMX6ul SPI interface for data reading, ADC is TI's ADC124S051. When using spi_sync, the data can be read correctly. When using spi_async to read data, some error data will be collected. Below is my driver core code:

static int adc124s_adc_conversion(struct spi_device *spi, int count)

{

int i,ret;

u8 tx_buffer[1600];

struct spi_transfer spi_trans_low = {

.rx_buf = mmap_buffer,

.tx_buf = tx_buffer,

.len = 1496,

//.cs_change = 0,

.speed_hz = 5000000,

.bits_per_word = BITS_PER_WORD,

};

struct spi_transfer spi_trans_high = {

.rx_buf = mmap_buffer + 1496,

.tx_buf = tx_buffer,

.len = 1496,

//.cs_change = 0,

.speed_hz = 5000000,

.bits_per_word = BITS_PER_WORD,

};

struct spi_message message_low;

struct spi_message message_high;

ret = 0;

for(i=0;i<1600;i++)

{

tx_buffer[i] = 0;

}

/* Do the transfer */

switch(count)

{

case 1:

date = 1;

spi_message_init(&message_low);

message_low.complete = adc_complete;

message_low.context = NULL;

spi_message_add_tail(&spi_trans_low, &message_low);

ret=spi_async(spi, &message_low);

break;

case 2:

date = 2;

spi_message_init(&message_high);

message_high.complete = adc_complete;

message_high.context = NULL;

spi_message_add_tail(&spi_trans_high, &message_high);

ret=spi_async(spi, &message_high);

break;

default:

printk("input count is err\n");

break;

}

return ret;

}

static void adc_complete(void *context)

{

int ret,i;

switch(date)

{

case 1:

//可读时第三个参数设置为POLL_IN,可写时第三个参数设置为POLL_OUT

//在这里将其仅仅作为一个参数值，POLL_IN=1；POLL_OUT=2

for(i=0;i<748;i++)

{

printk("this is mmap_buffer[%d] : %d\n",i*2,mmap_buffer[i*2]);

}

kill_fasync(&button_async, SIGIO, POLL_IN);

msleep(3000);

ret=adc124s_adc_conversion(g_spi,2);

break;

case 2:

for(i=748;i<1496;i++)

{

printk("this is mmap_buffer[%d] : %d\n",i*2,mmap_buffer[i*2]);

}

kill_fasync(&button_async, SIGIO, POLL_OUT);

msleep(3000);

ret=adc124s_adc_conversion(g_spi,1);

break;

default: printk("this is faile\n");

break;

}

static ssize_t adc124s_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)

{

int ret = 0;

ret=adc124s_adc_conversion(g_spi,1);/* count每次读取的数据量 */

return ret;

}

Re: spi_async data wrong in linux!!

igorpadykov — Fri, 12 Jul 2019 04:48:03 GMT

Hi 永磊李

what bsp used in the case, one can try with latest nxp

linux-imx - i.MX Linux kernel

also if sdma is used in the case one can try to disable sdma.

Best regards
igor
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Re: spi_async data wrong in linux!!

yongleili717 — Fri, 12 Jul 2019 06:22:24 GMT

Linux 4.1.15，

Re: spi_async data wrong in linux!!

igorpadykov — Fri, 12 Jul 2019 14:49:04 GMT

please try with latest nxp

linux-imx - i.MX Linux kernel

Best regards
igor

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spi_async data wrong in linux!!

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Re: spi_async data wrong in linux!!