On 12/8/2017 4:11 AM, Lothar Wa?mann wrote:

quoted

While implementing the ACPI piece, I have to convert an unsigned long to
(const void *) in ACPI code so that the APIs are compatible.

Just one more remark: Do you need write access to the data the pointer
returned by device_get_match_data() or of_fwnode_get_match_data()
points to?
If not, the return type of those functions should be 'const void *'.

Yes, the only reason driver is trying to obtain this data pointer is to modify
members of it. I did a quick test with your suggestion.

test.c: In function ?main?:
test.c:15:2: error: assignment of member ?m? in read-only object
  t->m = 3;
  ^

struct test
{
        int m;
};

int main(void)
{
        const void *ptr;
        unsigned long l =4;
        const struct test *t;

        ptr = (const void *)l;

        t = ptr;
        t->m = 3;
}



-- 
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.