On Wed, Nov 21, 2012 at 12:48:43PM +0100, Steffen Trumtrar wrote:
Hi!
On Wed, Nov 21, 2012 at 10:12:43AM +0000, Manjunathappa, Prakash wrote:
Hi Steffen,
On Tue, Nov 20, 2012 at 21:24:52, Steffen Trumtrar wrote:
+/**
- of_get_display_timings - parse all display_timing entries from a device_node
- @np: device_node with the subnodes
- **/
+struct display_timings *of_get_display_timings(const struct device_node *np) +{
- struct device_node *timings_np;
- struct device_node *entry;
- struct device_node *native_mode;
- struct display_timings *disp;
- if (!np) {
pr_err("%s: no devicenode given\n", __func__);return NULL;- }
- timings_np = of_find_node_by_name(np, "display-timings");
I get below build warnings on this line drivers/video/of_display_timing.c: In function 'of_get_display_timings': drivers/video/of_display_timing.c:109:2: warning: passing argument 1 of 'of_find_node_by_name' discards qualifiers from pointer target type include/linux/of.h:167:28: note: expected 'struct device_node *' but argument is of type 'const struct device_node *'
- of_display_timings_exists - check if a display-timings node is provided
- @np: device_node with the timing
- **/
+int of_display_timings_exists(const struct device_node *np) +{
- struct device_node *timings_np;
- if (!np)
return -EINVAL;- timings_np = of_parse_phandle(np, "display-timings", 0);
Also here: drivers/video/of_display_timing.c: In function 'of_display_timings_exists': drivers/video/of_display_timing.c:209:2: warning: passing argument 1 of 'of_parse_phandle' discards qualifiers from pointer target type include/linux/of.h:258:28: note: expected 'struct device_node *' but argument is of type 'const struct device_node *'
The warnings are because the of-functions do not use const pointers where they should. I had two options: don't use const pointers even if they should be and have no warnings or use const pointers and have a correct API. (Third option: send patches for of-functions). I chose the second option.
Maybe a better approach would be a combination of 1 and 3: don't use const pointers for struct device_node for now and bring the issue up with the OF maintainers, possibly with patches attached that fix the problematic functions.
Thierry