Re: [PATCH] [media] exynos4-is: Add missing 'of_node_put'

[Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>]

Le 24/02/2017 à 22:19, Javier Martinez Canillas a écrit :
> Thanks for the patch, but Krzysztof sent the exact same patch before 
> [0]. There
> was feedback from Sylwester at the time that you can also look at [0]. Could you
> please take that into account and post a patch according to what he suggested?
>
> [0]: http://lists.infradead.org/pipermail/linux-arm-kernel/2016-March/415207.html
>
> Best regards,

Hi,

apparently, the patch has already been taken into -next by Mauro 
Carvalho Chehab.

Moreover, I personally don't think that what is proposed in [0] is more 
readable.
There is not that much code between 'of_get_next_child' and 
'of_node_put' in the normal path and not so many error handling paths 
between the 2 function calls.
Adding some indentation level is not an improvement, IMHO.

If you really want, I could propose something like the code below (not 
carefully checked, just to give an idea), but honestly, I don't think it 
is needed.
It avoids some new indent and avoids duplicating 'of_node_put'.

Tell me if you think it is an improvement and I'll send a patch.

CJ


diff --git a/drivers/media/platform/exynos4-is/media-dev.c 
b/drivers/media/platform/exynos4-is/media-dev.c
index e3a8709138fa..da5b76c1df98 100644
--- a/drivers/media/platform/exynos4-is/media-dev.c
+++ b/drivers/media/platform/exynos4-is/media-dev.c
@@ -385,38 +385,35 @@ static void fimc_md_pipelines_free(struct fimc_md 
*fmd)
 static int fimc_md_parse_port_node(struct fimc_md *fmd,
                    struct device_node *port,
                    unsigned int index)
 {
     struct fimc_source_info *pd = &fmd->sensor[index].pdata;
-    struct device_node *rem, *ep, *np;
+    struct device_node *rem = NULL, *ep = NULL, *np;
     struct v4l2_of_endpoint endpoint;
     int ret;

     /* Assume here a port node can have only one endpoint node. */
     ep = of_get_next_child(port, NULL);
     if (!ep)
         return 0;

     ret = v4l2_of_parse_endpoint(ep, &endpoint);
-    if (ret) {
-        of_node_put(ep);
-        return ret;
-    }
+    if (ret)
+        goto put_ep;

     if (WARN_ON(endpoint.base.port == 0) || index >= FIMC_MAX_SENSORS) {
-        of_node_put(ep);
-        return -EINVAL;
+        ret = -EINVAL;
+        goto put_ep;
     }

     pd->mux_id = (endpoint.base.port - 1) & 0x1;

     rem = of_graph_get_remote_port_parent(ep);
-    of_node_put(ep);
     if (rem == NULL) {
         v4l2_info(&fmd->v4l2_dev, "Remote device at %s not found\n",
                             ep->full_name);
-        return 0;
+        goto out;
     }

     if (fimc_input_is_parallel(endpoint.base.port)) {
         if (endpoint.bus_type == V4L2_MBUS_PARALLEL)
             pd->sensor_bus_type = FIMC_BUS_TYPE_ITU_601;
@@ -447,22 +444,28 @@ static int fimc_md_parse_port_node(struct fimc_md 
*fmd,
         pd->fimc_bus_type = FIMC_BUS_TYPE_ISP_WRITEBACK;
     else
         pd->fimc_bus_type = pd->sensor_bus_type;

     if (WARN_ON(index >= ARRAY_SIZE(fmd->sensor))) {
-        of_node_put(rem);
-        return -EINVAL;
+        ret = -EINVAL;
+        goto put_rem;
     }

     fmd->sensor[index].asd.match_type = V4L2_ASYNC_MATCH_OF;
     fmd->sensor[index].asd.match.of.node = rem;
     fmd->async_subdevs[index] = &fmd->sensor[index].asd;

     fmd->num_sensors++;
+out:
+    ret = 0;

+put_rem:
     of_node_put(rem);
-    return 0;
+
+put_ep:
+    of_node_put(ep);
+    return ret;
 }

 /* Register all SoC external sub-devices */
 static int fimc_md_register_sensor_entities(struct fimc_md *fmd)
 {