+Most of drivers use, though, rather the newly introduced "managed
+buffer allocation mode" instead of the manual allocation or release.
+This is done by calling :c:func:`snd_pcm_set_managed_buffer_all()`
+instead of :c:func:`snd_pcm_lib_preallocate_pages_for_all()`.
+
+::
+
+ snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
+ &pci->dev, size, max);
+
+where passed arguments are identical in both functions.
+The difference in the managed mode is that PCM core will call
+:c:func:`snd_pcm_lib_malloc_pages()` internally already before calling
+the PCM ``hw_params`` callback, and call :c:func:`snd_pcm_lib_free_pages()`
+after the PCM ``hw_free`` callback automatically. So the driver
+doesn't have to call these functions explicitly in its callback any
+longer. This made many driver code having NULL ``hw_params`` and
+``hw_free`` entries.
+