staging: most: allow speculative configuration

This patch makes the driver accept a link configuration eventhough no
device is attached to the bus. Instead the configuration is being applied
as soon as a device is being registered with the core.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/configfs.c b/drivers/staging/most/configfs.c
index cb714f64d2792048290c2ed9bb0632173eaf09bd..aeeb5ec6199c9ba9a7958f7046157d0655526e21 100644 (file)
--- a/drivers/staging/most/configfs.c
+++ b/drivers/staging/most/configfs.c
@@ -14,6 +14,7 @@
 
 struct mdev_link {
        struct config_item item;
+       struct list_head list;
        bool create_link;
        u16 num_buffers;
        u16 buffer_size;
@@ -29,6 +30,8 @@ struct mdev_link {
        char comp_params[PAGE_SIZE];
 };
 
+struct list_head mdev_link_list;
+
 static int set_cfg_buffer_size(struct mdev_link *link)
 {
        if (!link->buffer_size)
@@ -106,33 +109,41 @@ static ssize_t mdev_link_create_link_show(struct config_item *item, char *page)
                        to_mdev_link(item)->create_link);
 }
 
+static int set_config_and_add_link(struct mdev_link *mdev_link)
+{
+       int i;
+       int ret;
+
+       for (i = 0; i < ARRAY_SIZE(set_config_val); i++) {
+               ret = set_config_val[i](mdev_link);
+               if (ret < 0 && ret != -ENODEV) {
+                       pr_err("Config failed\n");
+                       return ret;
+               }
+       }
+
+       return most_add_link(mdev_link->device, mdev_link->channel,
+                            mdev_link->comp, mdev_link->name,
+                            mdev_link->comp_params);
+}
+
 static ssize_t mdev_link_create_link_store(struct config_item *item,
                                           const char *page, size_t count)
 {
        struct mdev_link *mdev_link = to_mdev_link(item);
        bool tmp;
        int ret;
-       int i;
 
        ret = kstrtobool(page, &tmp);
        if (ret)
                return ret;
-
-       for (i = 0; i < ARRAY_SIZE(set_config_val); i++) {
-               ret = set_config_val[i](mdev_link);
-               if (ret < 0)
-                       return ret;
-       }
-
-       if (tmp)
-               ret = most_add_link(mdev_link->device, mdev_link->channel,
-                                   mdev_link->comp, mdev_link->name,
-                                   mdev_link->comp_params);
-       else
-               ret = most_remove_link(mdev_link->device, mdev_link->channel,
-                                      mdev_link->comp);
-       if (ret)
+       if (!tmp)
+               return most_remove_link(mdev_link->device, mdev_link->channel,
+                                       mdev_link->comp);
+       ret = set_config_and_add_link(mdev_link);
+       if (ret && ret != -ENODEV)
                return ret;
+       list_add_tail(&mdev_link->list, &mdev_link_list);
        mdev_link->create_link = tmp;
        return count;
 }
@@ -594,6 +605,22 @@ int most_register_configfs_subsys(struct core_component *c)
 }
 EXPORT_SYMBOL_GPL(most_register_configfs_subsys);
 
+void most_interface_register_notify(const char *mdev)
+{
+       bool register_snd_card = false;
+       struct mdev_link *mdev_link;
+
+       list_for_each_entry(mdev_link, &mdev_link_list, list) {
+               if (!strcmp(mdev_link->device, mdev)) {
+                       set_config_and_add_link(mdev_link);
+                       if (!strcmp(mdev_link->comp, "sound"))
+                               register_snd_card = true;
+               }
+       }
+       if (register_snd_card)
+               most_cfg_complete("sound");
+}
+
 void most_deregister_configfs_subsys(struct core_component *c)
 {
        if (!strcmp(c->name, "cdev"))
@@ -622,6 +649,7 @@ int __init configfs_init(void)
        mutex_init(&most_sound_subsys.subsys.su_mutex);
 
        INIT_LIST_HEAD(&most_sound_subsys.soundcard_list);
+       INIT_LIST_HEAD(&mdev_link_list);
 
        return 0;
 }

diff --git a/drivers/staging/most/core.c b/drivers/staging/most/core.c
index 03370551cd8b7a07e40510c1dd46f8951070a0a8..306db261cdccf1cf7569244a1e6ffb69f8095db1 100644 (file)
--- a/drivers/staging/most/core.c
+++ b/drivers/staging/most/core.c
@@ -720,19 +720,10 @@ int most_cfg_complete(char *comp_name)
 int most_add_link(char *mdev, char *mdev_ch, char *comp_name, char *link_name,
                  char *comp_param)
 {
-       struct most_channel *c;
-       struct core_component *comp;
-       char buf[STRING_SIZE];
+       struct most_channel *c = get_channel(mdev, mdev_ch);
+       struct core_component *comp = match_component(comp_name);
 
-       comp = match_component(comp_name);
-       if (!comp)
-               return -ENODEV;
-       if (!comp_param || *comp_param == 0) {
-               snprintf(buf, sizeof(buf), "%s-%s", mdev, mdev_ch);
-               comp_param = buf;
-       }
-       c = get_channel(mdev, mdev_ch);
-       if (!c)
+       if (!c || !comp)
                return -ENODEV;
 
        return link_channel_to_component(c, comp, link_name, comp_param);
@@ -1462,6 +1453,7 @@ int most_register_interface(struct most_interface *iface)
        }
        pr_info("registered new device mdev%d (%s)\n",
                id, iface->description);
+       most_interface_register_notify(iface->description);
        return 0;
 
 err_free_most_channel:

diff --git a/drivers/staging/most/core.h b/drivers/staging/most/core.h
index 12c5992c4229c7ba62f364bf625df6b259a43912..652aaa7710291040455911d0c712aa0fc8c1e7a2 100644 (file)
--- a/drivers/staging/most/core.h
+++ b/drivers/staging/most/core.h
@@ -334,4 +334,5 @@ int most_set_cfg_datatype(char *mdev, char *mdev_ch, char *buf);
 int most_set_cfg_direction(char *mdev, char *mdev_ch, char *buf);
 int most_set_cfg_packets_xact(char *mdev, char *mdev_ch, u16 val);
 int most_cfg_complete(char *comp_name);
+void most_interface_register_notify(const char *mdev_name);
 #endif /* MOST_CORE_H_ */

diff --git a/drivers/staging/most/sound/sound.c b/drivers/staging/most/sound/sound.c
index 6b5438c2495b3717e6b95cba7f64a150f64877d6..7c998673a6f8299f67d40b789568596148b1d486 100644 (file)
--- a/drivers/staging/most/sound/sound.c
+++ b/drivers/staging/most/sound/sound.c
@@ -20,6 +20,7 @@
 #include <most/core.h>
 
 #define DRIVER_NAME "sound"
+#define STRING_SIZE    80
 
 static struct core_component comp;
 
@@ -582,6 +583,7 @@ static int audio_probe_channel(struct most_interface *iface, int channel_id,
        int direction;
        u16 ch_num;
        char *sample_res;
+       char arg_list_cpy[STRING_SIZE];
 
        if (!iface)
                return -EINVAL;
@@ -590,8 +592,8 @@ static int audio_probe_channel(struct most_interface *iface, int channel_id,
                pr_err("Incompatible channel type\n");
                return -EINVAL;
        }
-
-       ret = split_arg_list(arg_list, &ch_num, &sample_res);
+       strlcpy(arg_list_cpy, arg_list, STRING_SIZE);
+       ret = split_arg_list(arg_list_cpy, &ch_num, &sample_res);
        if (ret < 0)
                return ret;