RE: [microblaze-uclinux] printk() is not triggered with the data passed in the application program

[Brettschneider Falk <fbrettschneider@xxxxxxxxxxxxxxxxx>]

Hi Kunal,

Kunal Kishore wrote:
> WRITE Data from user 0 hex 
...
> static ssize_t MY_Driver_write(struct file *file, const char *buf, size_t
count, loff_t *ppos)
> {
>     u8 data;
> 
>     if (copy_from_user(&data, buf, sizeof(data)))
>            return -EFAULT; 
>     printk("WRITE Data from user %x hex\n", data);
>     outb(data, OUTPORT);
>     return 0;
> }
...
> data=0x0f;
...
> if(write(handle, &data, 1, 0) < 0)
...

printk with %i or %d in the format string definitely works here.
1) Try to use %i instead of your %x
2) Try to printk your buf in MY_Driver_write
3) copy_from_user isn't necessary since there's no MMU on this platform.
I think outb(0) doesn't switch on any LED.

CU, F@lk
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