On Fri, 12 Nov 2010 13:18:41 +0000 Mark Brown broonie@opensource.wolfsonmicro.com wrote:
On Fri, Nov 12, 2010 at 11:23:25AM +0200, Jarkko Nikula wrote:
Cross-device paths are registered by listing the widgets from device A in a map for device B. An example below shows a path that connects MONO out of A into Line In of B:
static const struct snd_soc_dapm_route mapA[] = { {"MONO", NULL, "DAC"}, };
static const struct snd_soc_dapm_route mapB[] = { {"Line In", NULL, "MONO"}, };
This is going to fall over if we have widgets in two devices with the same name (and especially if we have two devices of the same kind in the system). Adding source device names to the paths would probably cover it with the same format but it should be considered and noted here.
That's the reason why the code favors a widget from current DAPM context in snd_soc_dapm_add_route so that no current machine would (hopefully) break because of this patch.
Of course any new code implementing cross-device paths between codecs with conflicting widget names would need the name prefixing stuff also.
struct snd_soc_dapm_context {
- struct list_head widgets;
- int n_widgets; /* number of widgets in this context */
I'm not sure why we need to count the number of widgets here;
True, this should go the next patch actually.
index 835087d..77be6b3 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -618,6 +618,7 @@ struct snd_soc_card { struct list_head platform_dev_list; struct list_head dai_dev_list;
- struct list_head widgets; struct list_head paths;
If we keep moving stuff into the card it's questionable what the context is buying us...
DAPM context represent the parent device (codecs currently and other devices in someday) and its state so I don't see we'll be removing it in near future even now the widgets and paths are moved to card.