[PATCH 4.19 058/125] ALSA: usb-audio: Simplify parse_audio_unit()

From: Greg Kroah-Hartman
Date: Mon Nov 11 2019 - 13:43:17 EST


From: Takashi Iwai <tiwai@xxxxxxx>

commit 68e9fde245591d18200f8a9054cac22339437adb upstream.

Minor code refactoring by combining the UAC version and the type in
the switch-case flow, so that we reduce the indentation and
redundancy. One good bonus is that the duplicated definition of the
same type value (e.g. UAC2_EFFECT_UNIT) can be handled more cleanly.

Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
sound/usb/mixer.c | 95 ++++++++++++++++++++++--------------------------------
1 file changed, 39 insertions(+), 56 deletions(-)

--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -2801,62 +2801,45 @@ static int parse_audio_unit(struct mixer
return 0; /* skip invalid unit */
}

- if (protocol == UAC_VERSION_1 || protocol == UAC_VERSION_2) {
- switch (p1[2]) {
- case UAC_INPUT_TERMINAL:
- return parse_audio_input_terminal(state, unitid, p1);
- case UAC_MIXER_UNIT:
- return parse_audio_mixer_unit(state, unitid, p1);
- case UAC2_CLOCK_SOURCE:
- return parse_clock_source_unit(state, unitid, p1);
- case UAC_SELECTOR_UNIT:
- case UAC2_CLOCK_SELECTOR:
- return parse_audio_selector_unit(state, unitid, p1);
- case UAC_FEATURE_UNIT:
- return parse_audio_feature_unit(state, unitid, p1);
- case UAC1_PROCESSING_UNIT:
- /* UAC2_EFFECT_UNIT has the same value */
- if (protocol == UAC_VERSION_1)
- return parse_audio_processing_unit(state, unitid, p1);
- else
- return 0; /* FIXME - effect units not implemented yet */
- case UAC1_EXTENSION_UNIT:
- /* UAC2_PROCESSING_UNIT_V2 has the same value */
- if (protocol == UAC_VERSION_1)
- return parse_audio_extension_unit(state, unitid, p1);
- else /* UAC_VERSION_2 */
- return parse_audio_processing_unit(state, unitid, p1);
- case UAC2_EXTENSION_UNIT_V2:
- return parse_audio_extension_unit(state, unitid, p1);
- default:
- usb_audio_err(state->chip,
- "unit %u: unexpected type 0x%02x\n", unitid, p1[2]);
- return -EINVAL;
- }
- } else { /* UAC_VERSION_3 */
- switch (p1[2]) {
- case UAC_INPUT_TERMINAL:
- return parse_audio_input_terminal(state, unitid, p1);
- case UAC3_MIXER_UNIT:
- return parse_audio_mixer_unit(state, unitid, p1);
- case UAC3_CLOCK_SOURCE:
- return parse_clock_source_unit(state, unitid, p1);
- case UAC3_SELECTOR_UNIT:
- case UAC3_CLOCK_SELECTOR:
- return parse_audio_selector_unit(state, unitid, p1);
- case UAC3_FEATURE_UNIT:
- return parse_audio_feature_unit(state, unitid, p1);
- case UAC3_EFFECT_UNIT:
- return 0; /* FIXME - effect units not implemented yet */
- case UAC3_PROCESSING_UNIT:
- return parse_audio_processing_unit(state, unitid, p1);
- case UAC3_EXTENSION_UNIT:
- return parse_audio_extension_unit(state, unitid, p1);
- default:
- usb_audio_err(state->chip,
- "unit %u: unexpected type 0x%02x\n", unitid, p1[2]);
- return -EINVAL;
- }
+#define PTYPE(a, b) ((a) << 8 | (b))
+ switch (PTYPE(protocol, p1[2])) {
+ case PTYPE(UAC_VERSION_1, UAC_INPUT_TERMINAL):
+ case PTYPE(UAC_VERSION_2, UAC_INPUT_TERMINAL):
+ case PTYPE(UAC_VERSION_3, UAC_INPUT_TERMINAL):
+ return parse_audio_input_terminal(state, unitid, p1);
+ case PTYPE(UAC_VERSION_1, UAC_MIXER_UNIT):
+ case PTYPE(UAC_VERSION_2, UAC_MIXER_UNIT):
+ case PTYPE(UAC_VERSION_3, UAC3_MIXER_UNIT):
+ return parse_audio_mixer_unit(state, unitid, p1);
+ case PTYPE(UAC_VERSION_2, UAC2_CLOCK_SOURCE):
+ case PTYPE(UAC_VERSION_3, UAC3_CLOCK_SOURCE):
+ return parse_clock_source_unit(state, unitid, p1);
+ case PTYPE(UAC_VERSION_1, UAC_SELECTOR_UNIT):
+ case PTYPE(UAC_VERSION_2, UAC_SELECTOR_UNIT):
+ case PTYPE(UAC_VERSION_3, UAC3_SELECTOR_UNIT):
+ case PTYPE(UAC_VERSION_2, UAC2_CLOCK_SELECTOR):
+ case PTYPE(UAC_VERSION_3, UAC3_CLOCK_SELECTOR):
+ return parse_audio_selector_unit(state, unitid, p1);
+ case PTYPE(UAC_VERSION_1, UAC_FEATURE_UNIT):
+ case PTYPE(UAC_VERSION_2, UAC_FEATURE_UNIT):
+ case PTYPE(UAC_VERSION_3, UAC3_FEATURE_UNIT):
+ return parse_audio_feature_unit(state, unitid, p1);
+ case PTYPE(UAC_VERSION_1, UAC1_PROCESSING_UNIT):
+ case PTYPE(UAC_VERSION_2, UAC2_PROCESSING_UNIT_V2):
+ case PTYPE(UAC_VERSION_3, UAC3_PROCESSING_UNIT):
+ return parse_audio_processing_unit(state, unitid, p1);
+ case PTYPE(UAC_VERSION_1, UAC1_EXTENSION_UNIT):
+ case PTYPE(UAC_VERSION_2, UAC2_EXTENSION_UNIT_V2):
+ case PTYPE(UAC_VERSION_3, UAC3_EXTENSION_UNIT):
+ return parse_audio_extension_unit(state, unitid, p1);
+ case PTYPE(UAC_VERSION_2, UAC2_EFFECT_UNIT):
+ case PTYPE(UAC_VERSION_3, UAC3_EFFECT_UNIT):
+ return 0; /* FIXME - effect units not implemented yet */
+ default:
+ usb_audio_err(state->chip,
+ "unit %u: unexpected type 0x%02x\n",
+ unitid, p1[2]);
+ return -EINVAL;
}
}