[PATCH 4.19 061/125] ALSA: usb-audio: Clean up check_input_term()

From: Greg Kroah-Hartman
Date: Mon Nov 11 2019 - 14:04:22 EST


From: Takashi Iwai <tiwai@xxxxxxx>

commit e0ccdef92653f8867e2d1667facfd3c23699f540 upstream.

The primary changes in this patch are cleanups of __check_input_term()
and move to a non-nested switch-case block by evaluating the pair of
UAC version and the unit type, as we've done for parse_audio_unit().
Also each parser is split into the function for readability.

Now, a slight behavior change by this cleanup is the handling of
processing and extension units. Formerly we've dealt with them
differently between UAC1/2 and UAC3; the latter returns an error if no
input sources are available, while the former continues to parse.

In this patch, unify the behavior in all cases: when input sources are
available, it parses recursively, then override the type and the id,
as well as channel information if not provided yet.

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

---
sound/usb/mixer.c | 407 ++++++++++++++++++++++++++++--------------------------
1 file changed, 212 insertions(+), 195 deletions(-)

--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -773,224 +773,242 @@ static int uac_mixer_unit_get_channels(s
}

/*
- * parse the source unit recursively until it reaches to a terminal
- * or a branched unit.
+ * Parse Input Terminal Unit
*/
static int __check_input_term(struct mixer_build *state, int id,
- struct usb_audio_term *term)
+ struct usb_audio_term *term);
+
+static int parse_term_uac1_iterm_unit(struct mixer_build *state,
+ struct usb_audio_term *term,
+ void *p1, int id)
+{
+ struct uac_input_terminal_descriptor *d = p1;
+
+ term->type = le16_to_cpu(d->wTerminalType);
+ term->channels = d->bNrChannels;
+ term->chconfig = le16_to_cpu(d->wChannelConfig);
+ term->name = d->iTerminal;
+ return 0;
+}
+
+static int parse_term_uac2_iterm_unit(struct mixer_build *state,
+ struct usb_audio_term *term,
+ void *p1, int id)
{
- int protocol = state->mixer->protocol;
+ struct uac2_input_terminal_descriptor *d = p1;
int err;
- void *p1;
- unsigned char *hdr;

- memset(term, 0, sizeof(*term));
- for (;;) {
- /* a loop in the terminal chain? */
- if (test_and_set_bit(id, state->termbitmap))
- return -EINVAL;
+ /* call recursively to verify the referenced clock entity */
+ err = __check_input_term(state, d->bCSourceID, term);
+ if (err < 0)
+ return err;

- p1 = find_audio_control_unit(state, id);
- if (!p1)
- break;
- if (!snd_usb_validate_audio_desc(p1, protocol))
- break; /* bad descriptor */
+ /* save input term properties after recursion,
+ * to ensure they are not overriden by the recursion calls
+ */
+ term->id = id;
+ term->type = le16_to_cpu(d->wTerminalType);
+ term->channels = d->bNrChannels;
+ term->chconfig = le32_to_cpu(d->bmChannelConfig);
+ term->name = d->iTerminal;
+ return 0;
+}

- hdr = p1;
- term->id = id;
+static int parse_term_uac3_iterm_unit(struct mixer_build *state,
+ struct usb_audio_term *term,
+ void *p1, int id)
+{
+ struct uac3_input_terminal_descriptor *d = p1;
+ int err;

- if (protocol == UAC_VERSION_1 || protocol == UAC_VERSION_2) {
- switch (hdr[2]) {
- case UAC_INPUT_TERMINAL:
- if (protocol == UAC_VERSION_1) {
- struct uac_input_terminal_descriptor *d = p1;
-
- term->type = le16_to_cpu(d->wTerminalType);
- term->channels = d->bNrChannels;
- term->chconfig = le16_to_cpu(d->wChannelConfig);
- term->name = d->iTerminal;
- } else { /* UAC_VERSION_2 */
- struct uac2_input_terminal_descriptor *d = p1;
-
- /* call recursively to verify that the
- * referenced clock entity is valid */
- err = __check_input_term(state, d->bCSourceID, term);
- if (err < 0)
- return err;
-
- /* save input term properties after recursion,
- * to ensure they are not overriden by the
- * recursion calls */
- term->id = id;
- term->type = le16_to_cpu(d->wTerminalType);
- term->channels = d->bNrChannels;
- term->chconfig = le32_to_cpu(d->bmChannelConfig);
- term->name = d->iTerminal;
- }
- return 0;
- case UAC_FEATURE_UNIT: {
- /* the header is the same for v1 and v2 */
- struct uac_feature_unit_descriptor *d = p1;
+ /* call recursively to verify the referenced clock entity */
+ err = __check_input_term(state, d->bCSourceID, term);
+ if (err < 0)
+ return err;

- id = d->bSourceID;
- break; /* continue to parse */
- }
- case UAC_MIXER_UNIT: {
- struct uac_mixer_unit_descriptor *d = p1;
+ /* save input term properties after recursion,
+ * to ensure they are not overriden by the recursion calls
+ */
+ term->id = id;
+ term->type = le16_to_cpu(d->wTerminalType);

- term->type = UAC3_MIXER_UNIT << 16; /* virtual type */
- term->channels = uac_mixer_unit_bNrChannels(d);
- term->chconfig = uac_mixer_unit_wChannelConfig(d, protocol);
- term->name = uac_mixer_unit_iMixer(d);
- return 0;
- }
- case UAC_SELECTOR_UNIT:
- case UAC2_CLOCK_SELECTOR: {
- struct uac_selector_unit_descriptor *d = p1;
- /* call recursively to retrieve the channel info */
- err = __check_input_term(state, d->baSourceID[0], term);
- if (err < 0)
- return err;
- term->type = UAC3_SELECTOR_UNIT << 16; /* virtual type */
- term->id = id;
- term->name = uac_selector_unit_iSelector(d);
- return 0;
- }
- case UAC1_PROCESSING_UNIT:
- /* UAC2_EFFECT_UNIT */
- if (protocol == UAC_VERSION_1)
- term->type = UAC3_PROCESSING_UNIT << 16; /* virtual type */
- else /* UAC_VERSION_2 */
- term->type = UAC3_EFFECT_UNIT << 16; /* virtual type */
- /* fall through */
- case UAC1_EXTENSION_UNIT:
- /* UAC2_PROCESSING_UNIT_V2 */
- if (protocol == UAC_VERSION_1 && !term->type)
- term->type = UAC3_EXTENSION_UNIT << 16; /* virtual type */
- else if (protocol == UAC_VERSION_2 && !term->type)
- term->type = UAC3_PROCESSING_UNIT << 16; /* virtual type */
- /* fall through */
- case UAC2_EXTENSION_UNIT_V2: {
- struct uac_processing_unit_descriptor *d = p1;
-
- if (protocol == UAC_VERSION_2 &&
- hdr[2] == UAC2_EFFECT_UNIT) {
- /* UAC2/UAC1 unit IDs overlap here in an
- * uncompatible way. Ignore this unit for now.
- */
- return 0;
- }
+ err = get_cluster_channels_v3(state, le16_to_cpu(d->wClusterDescrID));
+ if (err < 0)
+ return err;
+ term->channels = err;

- if (d->bNrInPins) {
- id = d->baSourceID[0];
- break; /* continue to parse */
- }
- if (!term->type)
- term->type = UAC3_EXTENSION_UNIT << 16; /* virtual type */
+ /* REVISIT: UAC3 IT doesn't have channels cfg */
+ term->chconfig = 0;

- term->channels = uac_processing_unit_bNrChannels(d);
- term->chconfig = uac_processing_unit_wChannelConfig(d, protocol);
- term->name = uac_processing_unit_iProcessing(d, protocol);
- return 0;
- }
- case UAC2_CLOCK_SOURCE: {
- struct uac_clock_source_descriptor *d = p1;
+ term->name = le16_to_cpu(d->wTerminalDescrStr);
+ return 0;
+}

- term->type = UAC3_CLOCK_SOURCE << 16; /* virtual type */
- term->id = id;
- term->name = d->iClockSource;
- return 0;
- }
- default:
- return -ENODEV;
- }
- } else { /* UAC_VERSION_3 */
- switch (hdr[2]) {
- case UAC_INPUT_TERMINAL: {
- struct uac3_input_terminal_descriptor *d = p1;
-
- /* call recursively to verify that the
- * referenced clock entity is valid */
- err = __check_input_term(state, d->bCSourceID, term);
- if (err < 0)
- return err;
-
- /* save input term properties after recursion,
- * to ensure they are not overriden by the
- * recursion calls */
- term->id = id;
- term->type = le16_to_cpu(d->wTerminalType);
-
- err = get_cluster_channels_v3(state, le16_to_cpu(d->wClusterDescrID));
- if (err < 0)
- return err;
- term->channels = err;
+static int parse_term_mixer_unit(struct mixer_build *state,
+ struct usb_audio_term *term,
+ void *p1, int id)
+{
+ struct uac_mixer_unit_descriptor *d = p1;
+ int protocol = state->mixer->protocol;
+ int err;

- /* REVISIT: UAC3 IT doesn't have channels cfg */
- term->chconfig = 0;
+ err = uac_mixer_unit_get_channels(state, d);
+ if (err <= 0)
+ return err;

- term->name = le16_to_cpu(d->wTerminalDescrStr);
- return 0;
- }
- case UAC3_FEATURE_UNIT: {
- struct uac3_feature_unit_descriptor *d = p1;
+ term->type = UAC3_MIXER_UNIT << 16; /* virtual type */
+ term->channels = err;
+ if (protocol != UAC_VERSION_3) {
+ term->chconfig = uac_mixer_unit_wChannelConfig(d, protocol);
+ term->name = uac_mixer_unit_iMixer(d);
+ }
+ return 0;
+}

- id = d->bSourceID;
- break; /* continue to parse */
- }
- case UAC3_CLOCK_SOURCE: {
- struct uac3_clock_source_descriptor *d = p1;
+static int parse_term_selector_unit(struct mixer_build *state,
+ struct usb_audio_term *term,
+ void *p1, int id)
+{
+ struct uac_selector_unit_descriptor *d = p1;
+ int err;

- term->type = UAC3_CLOCK_SOURCE << 16; /* virtual type */
- term->id = id;
- term->name = le16_to_cpu(d->wClockSourceStr);
- return 0;
- }
- case UAC3_MIXER_UNIT: {
- struct uac_mixer_unit_descriptor *d = p1;
+ /* call recursively to retrieve the channel info */
+ err = __check_input_term(state, d->baSourceID[0], term);
+ if (err < 0)
+ return err;
+ term->type = UAC3_SELECTOR_UNIT << 16; /* virtual type */
+ term->id = id;
+ if (state->mixer->protocol != UAC_VERSION_3)
+ term->name = uac_selector_unit_iSelector(d);
+ return 0;
+}

- err = uac_mixer_unit_get_channels(state, d);
- if (err <= 0)
- return err;
+static int parse_term_proc_unit(struct mixer_build *state,
+ struct usb_audio_term *term,
+ void *p1, int id, int vtype)
+{
+ struct uac_processing_unit_descriptor *d = p1;
+ int protocol = state->mixer->protocol;
+ int err;

- term->channels = err;
- term->type = UAC3_MIXER_UNIT << 16; /* virtual type */
+ if (d->bNrInPins) {
+ /* call recursively to retrieve the channel info */
+ err = __check_input_term(state, d->baSourceID[0], term);
+ if (err < 0)
+ return err;
+ }

- return 0;
- }
- case UAC3_SELECTOR_UNIT:
- case UAC3_CLOCK_SELECTOR: {
- struct uac_selector_unit_descriptor *d = p1;
- /* call recursively to retrieve the channel info */
- err = __check_input_term(state, d->baSourceID[0], term);
- if (err < 0)
- return err;
- term->type = UAC3_SELECTOR_UNIT << 16; /* virtual type */
- term->id = id;
- term->name = 0; /* TODO: UAC3 Class-specific strings */
+ term->type = vtype << 16; /* virtual type */
+ term->id = id;

- return 0;
- }
- case UAC3_PROCESSING_UNIT: {
- struct uac_processing_unit_descriptor *d = p1;
+ if (protocol == UAC_VERSION_3)
+ return 0;

- if (!d->bNrInPins)
- return -EINVAL;
+ if (!term->channels) {
+ term->channels = uac_processing_unit_bNrChannels(d);
+ term->chconfig = uac_processing_unit_wChannelConfig(d, protocol);
+ }
+ term->name = uac_processing_unit_iProcessing(d, protocol);
+ return 0;
+}
+
+static int parse_term_uac2_clock_source(struct mixer_build *state,
+ struct usb_audio_term *term,
+ void *p1, int id)
+{
+ struct uac_clock_source_descriptor *d = p1;
+
+ term->type = UAC3_CLOCK_SOURCE << 16; /* virtual type */
+ term->id = id;
+ term->name = d->iClockSource;
+ return 0;
+}

- /* call recursively to retrieve the channel info */
- err = __check_input_term(state, d->baSourceID[0], term);
- if (err < 0)
- return err;
-
- term->type = UAC3_PROCESSING_UNIT << 16; /* virtual type */
- term->id = id;
- term->name = 0; /* TODO: UAC3 Class-specific strings */
+static int parse_term_uac3_clock_source(struct mixer_build *state,
+ struct usb_audio_term *term,
+ void *p1, int id)
+{
+ struct uac3_clock_source_descriptor *d = p1;
+
+ term->type = UAC3_CLOCK_SOURCE << 16; /* virtual type */
+ term->id = id;
+ term->name = le16_to_cpu(d->wClockSourceStr);
+ return 0;
+}

- return 0;
- }
- default:
- return -ENODEV;
- }
+#define PTYPE(a, b) ((a) << 8 | (b))
+
+/*
+ * parse the source unit recursively until it reaches to a terminal
+ * or a branched unit.
+ */
+static int __check_input_term(struct mixer_build *state, int id,
+ struct usb_audio_term *term)
+{
+ int protocol = state->mixer->protocol;
+ void *p1;
+ unsigned char *hdr;
+
+ for (;;) {
+ /* a loop in the terminal chain? */
+ if (test_and_set_bit(id, state->termbitmap))
+ return -EINVAL;
+
+ p1 = find_audio_control_unit(state, id);
+ if (!p1)
+ break;
+ if (!snd_usb_validate_audio_desc(p1, protocol))
+ break; /* bad descriptor */
+
+ hdr = p1;
+ term->id = id;
+
+ switch (PTYPE(protocol, hdr[2])) {
+ case PTYPE(UAC_VERSION_1, UAC_FEATURE_UNIT):
+ case PTYPE(UAC_VERSION_2, UAC_FEATURE_UNIT):
+ case PTYPE(UAC_VERSION_3, UAC3_FEATURE_UNIT): {
+ /* the header is the same for all versions */
+ struct uac_feature_unit_descriptor *d = p1;
+
+ id = d->bSourceID;
+ break; /* continue to parse */
+ }
+ case PTYPE(UAC_VERSION_1, UAC_INPUT_TERMINAL):
+ return parse_term_uac1_iterm_unit(state, term, p1, id);
+ case PTYPE(UAC_VERSION_2, UAC_INPUT_TERMINAL):
+ return parse_term_uac2_iterm_unit(state, term, p1, id);
+ case PTYPE(UAC_VERSION_3, UAC_INPUT_TERMINAL):
+ return parse_term_uac3_iterm_unit(state, term, p1, id);
+ 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_term_mixer_unit(state, term, p1, id);
+ case PTYPE(UAC_VERSION_1, UAC_SELECTOR_UNIT):
+ case PTYPE(UAC_VERSION_2, UAC_SELECTOR_UNIT):
+ case PTYPE(UAC_VERSION_2, UAC2_CLOCK_SELECTOR):
+ case PTYPE(UAC_VERSION_3, UAC3_SELECTOR_UNIT):
+ case PTYPE(UAC_VERSION_3, UAC3_CLOCK_SELECTOR):
+ return parse_term_selector_unit(state, term, p1, id);
+ 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_term_proc_unit(state, term, p1, id,
+ UAC3_PROCESSING_UNIT);
+ case PTYPE(UAC_VERSION_2, UAC2_EFFECT_UNIT):
+ case PTYPE(UAC_VERSION_3, UAC3_EFFECT_UNIT):
+ return parse_term_proc_unit(state, term, p1, id,
+ UAC3_EFFECT_UNIT);
+ 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_term_proc_unit(state, term, p1, id,
+ UAC3_EXTENSION_UNIT);
+ case PTYPE(UAC_VERSION_2, UAC2_CLOCK_SOURCE):
+ return parse_term_uac2_clock_source(state, term, p1, id);
+ case PTYPE(UAC_VERSION_3, UAC3_CLOCK_SOURCE):
+ return parse_term_uac3_clock_source(state, term, p1, id);
+ default:
+ return -ENODEV;
}
}
return -ENODEV;
@@ -2731,7 +2749,6 @@ static int parse_audio_unit(struct mixer
return 0; /* skip invalid unit */
}

-#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):