stm class: Plug stm device's unlink callback

STM device's unlink callback is never actually called from anywhere in
the stm class code.

This patch adds calls to stm driver's unlink method after the unlinking
has succeeded.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit cc8424074e51355e0c6ba717d8edc50d408f2802)

diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index e072652d9646dfc63b8fff93a5175ef53e9e5b94..0dd8f4c996f142aaa00d6a5c4d9b4ddb5918deba 100644 (file)
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -376,14 +376,19 @@ err_free:
 static int stm_char_release(struct inode *inode, struct file *file)
 {
        struct stm_file *stmf = file->private_data;
+       struct stm_device *stm = stmf->stm;
+
+       if (stm->data->unlink)
+               stm->data->unlink(stm->data, stmf->output.master,
+                                 stmf->output.channel);
 
-       stm_output_free(stmf->stm, &stmf->output);
+       stm_output_free(stm, &stmf->output);
 
        /*
         * matches the stm_char_open()'s
         * class_find_device() + try_module_get()
         */
-       stm_put_device(stmf->stm);
+       stm_put_device(stm);
        kfree(stmf);
 
        return 0;
@@ -865,8 +870,18 @@ unlock:
        spin_unlock(&src->link_lock);
        spin_unlock(&stm->link_lock);
 
-       if (!ret && src->data->unlink)
-               src->data->unlink(src->data);
+       /*
+        * Call the unlink callbacks for both source and stm, when we know
+        * that we have actually performed the unlinking.
+        */
+       if (!ret) {
+               if (src->data->unlink)
+                       src->data->unlink(src->data);
+
+               if (stm->data->unlink)
+                       stm->data->unlink(stm->data, src->output.master,
+                                         src->output.channel);
+       }
 
        return ret;
 }

diff --git a/include/linux/stm.h b/include/linux/stm.h
index ab8ceca4f5705aaeadda9ed8798559c450637d06..1a79ed8e43dadcb8d5884d17d73b2cd15e3a11d4 100644 (file)
--- a/include/linux/stm.h
+++ b/include/linux/stm.h
@@ -74,6 +74,9 @@ struct stm_device;
  *      it must return zero;
  *   3) if it does not support the requested packet type/flag combination,
  *      it must return -ENOTSUPP.
+ *
+ * The @unlink callback is called when there are no more active writers so
+ * that the master/channel can be quiesced.
  */
 struct stm_data {
        const char              *name;