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From: Ruslan Bilovol <ruslan.bilovol@gmail.com>
To: Takashi Iwai <tiwai@suse.com>
Cc: Jorge <jorge.sanjuan@codethink.co.uk>,
	Andrew Chant <achant@google.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 4/7] ALSA: usb: Only get AudioControl header for UAC1 class.
Date: Fri,  4 May 2018 04:24:01 +0300	[thread overview]
Message-ID: <1525397044-15080-5-git-send-email-ruslan.bilovol@gmail.com> (raw)
In-Reply-To: <1525397044-15080-1-git-send-email-ruslan.bilovol@gmail.com>

From: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>

The control header needs to be read from buffer at this point only
in the case of UAC1 protocol. Move it inside the switch case as other
protocols such as the Basic Audio Device spec will have an empty buffer
that is latter filled as inferred.

Signed-off-by: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>
[Ruslan: updated with recently added sanity checks]
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
---
 sound/usb/card.c | 39 +++++++++++++++++++--------------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 36c289b..0d7a5d7 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -221,32 +221,13 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 	struct usb_device *dev = chip->dev;
 	struct usb_host_interface *host_iface;
 	struct usb_interface_descriptor *altsd;
-	void *control_header;
 	int i, protocol;
-	int rest_bytes;
 
 	/* find audiocontrol interface */
 	host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
-	control_header = snd_usb_find_csint_desc(host_iface->extra,
-						 host_iface->extralen,
-						 NULL, UAC_HEADER);
 	altsd = get_iface_desc(host_iface);
 	protocol = altsd->bInterfaceProtocol;
 
-	if (!control_header) {
-		dev_err(&dev->dev, "cannot find UAC_HEADER\n");
-		return -EINVAL;
-	}
-
-	rest_bytes = (void *)(host_iface->extra + host_iface->extralen) -
-		control_header;
-
-	/* just to be sure -- this shouldn't hit at all */
-	if (rest_bytes <= 0) {
-		dev_err(&dev->dev, "invalid control header\n");
-		return -EINVAL;
-	}
-
 	switch (protocol) {
 	default:
 		dev_warn(&dev->dev,
@@ -255,7 +236,25 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 		/* fall through */
 
 	case UAC_VERSION_1: {
-		struct uac1_ac_header_descriptor *h1 = control_header;
+		struct uac1_ac_header_descriptor *h1;
+		int rest_bytes;
+
+		h1 = snd_usb_find_csint_desc(host_iface->extra,
+							 host_iface->extralen,
+							 NULL, UAC_HEADER);
+		if (!h1) {
+			dev_err(&dev->dev, "cannot find UAC_HEADER\n");
+			return -EINVAL;
+		}
+
+		rest_bytes = (void *)(host_iface->extra +
+				host_iface->extralen) - (void *)h1;
+
+		/* just to be sure -- this shouldn't hit at all */
+		if (rest_bytes <= 0) {
+			dev_err(&dev->dev, "invalid control header\n");
+			return -EINVAL;
+		}
 
 		if (rest_bytes < sizeof(*h1)) {
 			dev_err(&dev->dev, "too short v1 buffer descriptor\n");
-- 
1.9.1

  parent reply	other threads:[~2018-05-04  1:24 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-04  1:23 [PATCH v2 0/7] USB Audio Device Class 3.0 BADD profiles support Ruslan Bilovol
2018-05-04  1:23 ` [PATCH v2 1/7] ALSA: usb: stream: move audioformat alloc/init into separate function Ruslan Bilovol
2018-05-04  1:23 ` [PATCH v2 2/7] ALSA: usb: stream: refactor uac1/2 audio interface parsing Ruslan Bilovol
2018-05-04  1:24 ` [PATCH v2 3/7] ALSA: usb: stream: refactor uac3 " Ruslan Bilovol
2018-05-04  1:24 ` Ruslan Bilovol [this message]
2018-05-04  1:24 ` [PATCH v2 5/7] ALSA: usb: mixer: make string parsing independent of mixer_build state Ruslan Bilovol
2018-05-04  1:24 ` [PATCH v2 6/7] include: usb: audio-v3: add BADD-specific values Ruslan Bilovol
2018-05-04  1:24 ` [PATCH v2 7/7] ALSA: usb: add UAC3 BADD profiles support Ruslan Bilovol
2018-05-11 15:36   ` Jorge
2018-05-13  7:06     ` Takashi Iwai
2018-05-04  7:44 ` [PATCH v2 0/7] USB Audio Device Class 3.0 " Takashi Iwai

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