On Tue, 25 Jun 2019 23:54:18 +0200, Evan Green wrote:
The normal flow through the widget sysfs codepath is that snd_hdac_refresh_widgets() is called once without the sysfs bool set to set up codec->num_nodes and friends, then another time with the bool set to actually allocate all the sysfs widgets. However, during the first time allocation, hda_widget_sysfs_reinit() ignores the new num_nodes passed in via parameter and just calls hda_widget_sysfs_init(), using whatever was in codec->num_nodes before the update. This is not correct in cases where num_nodes changes. Here's an example:
Sometime earlier: snd_hdac_refresh_widgets(hdac, false) sets codec->num_nodes to 2, widgets is still not allocated
Now: snd_hdac_refresh_widgets(hdac, true) hda_widget_sysfs_reinit(num_nodes=7) hda_widget_sysfs_init() widget_tree_create() alloc(codec->num_nodes) // this is still 2 codec->num_nodes = 7
Pass num_nodes and start_nid down into widget_tree_create() so that the right number of nodes are allocated in all cases.
Signed-off-by: Evan Green evgreen@chromium.org
Thanks for the patch. That's indeed a problem, but I guess a simpler approach is just to return if sysfs didn't exist. If the sysfs entries aren't present at the second call with sysfs=true, it implies that the codec object will be exposed anyway later, and the sysfs will be created there. So, something like below would work instead?
thanks,
Takashi
--- a/sound/hda/hdac_sysfs.c +++ b/sound/hda/hdac_sysfs.c @@ -428,7 +428,7 @@ int hda_widget_sysfs_reinit(struct hdac_device *codec, int i;
if (!codec->widgets) - return hda_widget_sysfs_init(codec); + return 0;
tree = kmemdup(codec->widgets, sizeof(*tree), GFP_KERNEL); if (!tree)