From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eldad Zack , Takashi Iwai , Ben Hutchings , Weng Meiling Subject: [PATCH 3.4 103/134] ALSA: usb-audio: skip UAC2 EFFECT_UNIT Date: Wed, 9 Apr 2014 20:23:39 -0700 Message-Id: <20140410032312.984536104@linuxfoundation.org> In-Reply-To: <20140410032259.587501440@linuxfoundation.org> References: <20140410032259.587501440@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eldad Zack commit 5dae5fd24071319bb67d3375217d5b0b6d16cb0b upstream. Current code mishandles the case where the device is a UAC2 and the bDescriptorSubtype is a UAC2 Effect Unit (0x07). It tries to parse it as a Processing Unit (which is similar to two other UAC1 units with overlapping subtypes), but since the structure is different (See: 4.7.2.10, 4.7.2.11 in UAC2 standard), the parsing is done incorrectly and prevents the device from initializing. For now, just ignore the unit. Signed-off-by: Eldad Zack Signed-off-by: Takashi Iwai Signed-off-by: Ben Hutchings Cc: Weng Meiling Signed-off-by: Greg Kroah-Hartman --- sound/usb/mixer.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -720,8 +720,19 @@ static int check_input_term(struct mixer return 0; } case UAC1_PROCESSING_UNIT: - case UAC1_EXTENSION_UNIT: { + case UAC1_EXTENSION_UNIT: + /* UAC2_PROCESSING_UNIT_V2 */ + /* UAC2_EFFECT_UNIT */ { struct uac_processing_unit_descriptor *d = p1; + + if (state->mixer->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; + } + if (d->bNrInPins) { id = d->baSourceID[0]; break; /* continue to parse */