[alsa-devel] [PATCH 1/2] ALSA: snd-usb: mixer: propagate errors up the call chain
In check_input_term() and parse_audio_feature_unit(), propagate the error value that has been returned by a failing function instead of -EINVAL. That helps cleaning up the error pathes in the mixer.
Signed-off-by: Daniel Mack zonque@gmail.com --- sound/usb/mixer.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 638e7f7..db30d02 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -715,8 +715,9 @@ static int check_input_term(struct mixer_build *state, int id, struct usb_audio_ case UAC2_CLOCK_SELECTOR: { struct uac_selector_unit_descriptor *d = p1; /* call recursively to retrieve the channel info */ - if (check_input_term(state, d->baSourceID[0], term) < 0) - return -ENODEV; + err = check_input_term(state, d->baSourceID[0], term); + if (err < 0) + return err; term->type = d->bDescriptorSubtype << 16; /* virtual type */ term->id = id; term->name = uac_selector_unit_iSelector(d); @@ -1356,8 +1357,9 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void return err;
/* determine the input source type and name */ - if (check_input_term(state, hdr->bSourceID, &iterm) < 0) - return -EINVAL; + err = check_input_term(state, hdr->bSourceID, &iterm); + if (err < 0) + return err;
master_bits = snd_usb_combine_bytes(bmaControls, csize); /* master configuration quirks */
Creation of individual mixer controls may fail, but that shouldn't cause the entire mixer creation to fail. Even worse, if the mixer creation fails, that will error out the entire device probing.
All the functions called by parse_audio_unit() should return -EINVAL if they find descriptors that are unsupported or believed to be malformed, so we can safely handle this error code as a non-fatal condition in snd_usb_mixer_controls().
That fixes a long standing bug which is commonly worked around by adding quirks which make the driver ignore entire interfaces. Some of them might now be unnecessary.
Signed-off-by: Daniel Mack zonque@gmail.com Reported-and-tested-by: Rodolfo Thomazelli pe.soberbo@gmail.com --- sound/usb/mixer.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index db30d02..ac833f0 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -2120,7 +2120,7 @@ static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer) state.oterm.type = le16_to_cpu(desc->wTerminalType); state.oterm.name = desc->iTerminal; err = parse_audio_unit(&state, desc->bSourceID); - if (err < 0) + if (err < 0 && err != -EINVAL) return err; } else { /* UAC_VERSION_2 */ struct uac2_output_terminal_descriptor *desc = p; @@ -2132,12 +2132,12 @@ static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer) state.oterm.type = le16_to_cpu(desc->wTerminalType); state.oterm.name = desc->iTerminal; err = parse_audio_unit(&state, desc->bSourceID); - if (err < 0) + if (err < 0 && err != -EINVAL) return err;
/* for UAC2, use the same approach to also add the clock selectors */ err = parse_audio_unit(&state, desc->bCSourceID); - if (err < 0) + if (err < 0 && err != -EINVAL) return err; } }
At Tue, 19 Mar 2013 21:09:24 +0100, Daniel Mack wrote:
In check_input_term() and parse_audio_feature_unit(), propagate the error value that has been returned by a failing function instead of -EINVAL. That helps cleaning up the error pathes in the mixer.
Signed-off-by: Daniel Mack zonque@gmail.com
Applied both patches now with Cc to stable. Thanks.
Takashi
sound/usb/mixer.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 638e7f7..db30d02 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -715,8 +715,9 @@ static int check_input_term(struct mixer_build *state, int id, struct usb_audio_ case UAC2_CLOCK_SELECTOR: { struct uac_selector_unit_descriptor *d = p1; /* call recursively to retrieve the channel info */
if (check_input_term(state, d->baSourceID[0], term) < 0)return -ENODEV;
err = check_input_term(state, d->baSourceID[0], term);if (err < 0)return err; term->type = d->bDescriptorSubtype << 16; /* virtual type */ term->id = id; term->name = uac_selector_unit_iSelector(d);@@ -1356,8 +1357,9 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void return err;
/* determine the input source type and name */
- if (check_input_term(state, hdr->bSourceID, &iterm) < 0)
return -EINVAL;
err = check_input_term(state, hdr->bSourceID, &iterm);
if (err < 0)
return err;master_bits = snd_usb_combine_bytes(bmaControls, csize); /* master configuration quirks */
-- 1.8.1.4
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Daniel Mack -
Takashi Iwai