Re: [PATCH] ucm: Allow empty strings in "${var:...}" substitutions

On 6/27/20 1:30 PM, Hans de Goede wrote:

Recent ucm-conf changes introduce checks like this one in various places:

If.mspk { Condition { Type String Empty "${var:MonoSpeaker}" } True ... False ... }

The 'Empty "${var:MonoSpeaker}"' part can only every succeed if we do:

Define.MonoSpeaker ""

But so far that would result in an error like this one:

ALSA lib ucm_subs.c:367:(uc_mgr_get_substituted_value) variable '${var:MonoSpeaker}' is not defined in this context! ALSA lib main.c:983:(snd_use_case_mgr_open) error: failed to import cht-bsw-rt5672 use case configuration -22 alsaucm: error failed to open sound card cht-bsw-rt5672: Invalid argument

This commit fixes this by allowing empty values for "${var:...}" substitutions.

Signed-off-by: Hans de Goede hdegoede@redhat.com

Note besides the mentioned error, this also fixes similar errors I have been seeing on every board since alsa-ucm-conf commit d001c8de287f ("ucm.conf: add support for the kernel module name tree")

Well this is quite timely, I had to revert to older versions of UCM earlier today because of similar issues:

root@Zotac:~/alsa-lib# alsaucm -c SOF set _verb HiFi set _enadev Headphones ALSA lib ucm_subs.c:367:(uc_mgr_get_substituted_value) variable '${var:V1}' is not defined in this context! ALSA lib main.c:983:(snd_use_case_mgr_open) error: failed to import SOF use case configuration -22 alsaucm: error failed to open sound card SOF: Invalid argument

This error is gone with this patch + latest alsa-ucm-conf, so

Tested-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

Thanks Hans!

---

src/ucm/ucm_subs.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/ucm/ucm_subs.c b/src/ucm/ucm_subs.c index 293426f2..a154aa51 100644 --- a/src/ucm/ucm_subs.c +++ b/src/ucm/ucm_subs.c @@ -262,9 +262,10 @@ static char *rval_var(snd_use_case_mgr_t *uc_mgr, const char *id) goto __rval; \ }

-#define MATCH_VARIABLE2(name, id, fcn) \ +#define MATCH_VARIABLE2(name, id, fcn, empty_ok) \ if (strncmp((name), (id), sizeof(id) - 1) == 0) { \ idsize = sizeof(id) - 1; \

• allow_empty = (empty_ok);				\
  

  fcn2 = (fcn); \ goto __match2; \ }

@@ -314,11 +315,11 @@ __std: MATCH_VARIABLE(value, "${CardName}", rval_card_name, false); MATCH_VARIABLE(value, "${CardLongName}", rval_card_longname, false); MATCH_VARIABLE(value, "${CardComponents}", rval_card_components, true);

• MATCH_VARIABLE2(value, "${env:", rval_env);
  

• MATCH_VARIABLE2(value, "${sys:", rval_sysfs);
  

• MATCH_VARIABLE2(value, "${var:", rval_var);
  

• MATCH_VARIABLE2(value, "${CardNumberByName:", rval_card_number_by_name);
  

• MATCH_VARIABLE2(value, "${CardIdByName:", rval_card_id_by_name);
  

• MATCH_VARIABLE2(value, "${env:", rval_env, false);
  

• MATCH_VARIABLE2(value, "${sys:", rval_sysfs, false);
  

• MATCH_VARIABLE2(value, "${var:", rval_var, true);
  

• MATCH_VARIABLE2(value, "${CardNumberByName:", rval_card_number_by_name, false);
  

• MATCH_VARIABLE2(value, "${CardIdByName:", rval_card_id_by_name, false);
  

  __merr: err = -EINVAL; tmp = strchr(value, '}');