Hi Daniel,

It doesn't look like it..

The interrupt is invoked (via GPIO pin) only once and it's after the entire
packet is completely received.


On Wed, Jul 6, 2016 at 7:42 PM, Daniel. [off-list ref] wrote:

Hi, isn't it possible that your hal_frame_read be called again prior
rf_rx_completion_handler is called, and because of this calling
spi_message_init on a spi_message that is in spi queue yet?

2016-07-06 10:25 GMT-03:00 Moti Cohen [off-list ref]:

quoted

Hi all,



I'm trying to write a kernel device driver for a Freescale imx6 processor
based board.

This driver is using spi to communicate with a radio module (using linux
spi.c).

I managed to wr/rd from the module, however once I'm trying to read more
than 64 bytes I'm getting coruppted data. here are some details:




The SPI reading process goes as follows:

1.      Interrupt function is invoked from SPI device via dedicated GPIO
line.

2.       The interrupt function performs asynchronous SPI read in the
following order:

2.1   radio_trx_end_callback is called, as it is the registered call back
function.

2.2   radio_trx_end_callback calls hal_frame_read function which prepares
spi_message and spi_transfer structures and fill them with relevant data:
spi_device , data tx, transfer len , complete handler , ?

3.      The read itself  is done by calling to function spi_async

4.      The completion handler function is called and prints the read
message, but trying to read more than 64 bytes in one transaction causes

the

quoted

read data to be corrupted.

Any idea why am I seeing this behavior ?

Is there (in Linux) any definition for the size to be read via the SPI ?

The relevant variables and functions can be seen below:

Thanks in advance for helping..

__________________________

uint8_t rx_buf[200];

uint8_t reg[200] = {HAL_TRX_CMD_FR, 0xff, 0xff};

struct spi_transfer transfer;

struct spi_message  spi_msg;



// interrupt function

//-----------------------------------------------------------------------------------------------------------------------

quoted

static irq_handler_t radio_trx_end_callback(unsigned int irq, void

*dev_id,

quoted

struct pt_regs *regs)

{

    hal_frame_read(irq, dev_id);

    return (irq_handler_t) IRQ_HANDLED;      // Announce that the IRQ has
been handled correctly

}



//read function

//-----------------------------------------------------------------------------------------------------------------------

quoted

void hal_frame_read(unsigned int irq, void *dev_id)

{

        int status;

        spi_device->irq = irq;

        spi_message_init(&spi_msg);

        spi_msg.spi = spi_device;

        spi_msg.complete = rf_rx_completion_handler;

        spi_msg.context = NULL;

        memset((uint8_t*)&transfer, 0, sizeof(transfer));



        memset(rx_buf, 0xFF, sizeof(rx_buf));

        memset(reg, 0xFF, sizeof(reg));

        reg[0] = HAL_TRX_CMD_FR;

        transfer.tx_buf = reg;

        transfer.len =64;

        transfer.rx_buf = rx_buf;

        spi_message_add_tail(&transfer, &spi_msg);



        memset(rx_buf, 0x0, sizeof(rx_buf));

        status = spi_async(spi_device, &spi_msg);

    return;

}



//read completion handler

//-----------------------------------------------------------------------------------------------------------------------

quoted

static void rf_rx_completion_handler(void *arg)

{

        int ii;



//print the received message

printk("\npure message: rx_buf [1]-2=%02X\n      ", rx_buf [1]-2);

        for (ii=0; ii< rx_buf [1]-2; ii++)

                        printk("%02X ", rx_buf [2+ii]);





        printk("\nframe len=%X actual len=%X
status=%i\n",spi_msg.frame_length, spi_msg.actual_length,

spi_msg.status);

quoted

        send_up_rf_event_to_workque(TRX_END_EVENT);

}


_______________________________________________
Kernelnewbies mailing list
Kernelnewbies at kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

--
"Do or do not. There is no try"
  Yoda Master

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20160708/58f949a6/attachment.html