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authorAlexander Tsoy <alexander@tsoy.me>2020-04-18 20:58:15 +0300
committerTakashi Iwai <tiwai@suse.de>2020-04-18 22:08:39 +0300
commit1c826792586f526a5a5cd21d55aad388f5bb0b23 (patch)
tree2ef708bb656957a6e419eefa4c4ddf425a032044 /sound/usb/format.c
parentb392350ec3f229ad9603d3816f753479e441d99a (diff)
downloadlinux-1c826792586f526a5a5cd21d55aad388f5bb0b23.tar.xz
ALSA: usb-audio: Filter out unsupported sample rates on Focusrite devices
Many Focusrite devices supports a limited set of sample rates per altsetting. These includes audio interfaces with ADAT ports: - Scarlett 18i6, 18i8 1st gen, 18i20 1st gen; - Scarlett 18i8 2nd gen, 18i20 2nd gen; - Scarlett 18i8 3rd gen, 18i20 3rd gen; - Clarett 2Pre USB, 4Pre USB, 8Pre USB. Maximum rate is exposed in the last 4 bytes of Format Type descriptor which has a non-standard bLength = 10. Tested-by: Alexey Skobkin <skobkin-ru@ya.ru> Signed-off-by: Alexander Tsoy <alexander@tsoy.me> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200418175815.12211-1-alexander@tsoy.me Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/format.c')
-rw-r--r--sound/usb/format.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/sound/usb/format.c b/sound/usb/format.c
index 50e1874c847c..5ffb457cc88c 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -278,6 +278,52 @@ static bool s1810c_valid_sample_rate(struct audioformat *fp,
}
/*
+ * Many Focusrite devices supports a limited set of sampling rates per
+ * altsetting. Maximum rate is exposed in the last 4 bytes of Format Type
+ * descriptor which has a non-standard bLength = 10.
+ */
+static bool focusrite_valid_sample_rate(struct snd_usb_audio *chip,
+ struct audioformat *fp,
+ unsigned int rate)
+{
+ struct usb_interface *iface;
+ struct usb_host_interface *alts;
+ unsigned char *fmt;
+ unsigned int max_rate;
+
+ iface = usb_ifnum_to_if(chip->dev, fp->iface);
+ if (!iface)
+ return true;
+
+ alts = &iface->altsetting[fp->altset_idx];
+ fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
+ NULL, UAC_FORMAT_TYPE);
+ if (!fmt)
+ return true;
+
+ if (fmt[0] == 10) { /* bLength */
+ max_rate = combine_quad(&fmt[6]);
+
+ /* Validate max rate */
+ if (max_rate != 48000 &&
+ max_rate != 96000 &&
+ max_rate != 192000 &&
+ max_rate != 384000) {
+
+ usb_audio_info(chip,
+ "%u:%d : unexpected max rate: %u\n",
+ fp->iface, fp->altsetting, max_rate);
+
+ return true;
+ }
+
+ return rate <= max_rate;
+ }
+
+ return true;
+}
+
+/*
* Helper function to walk the array of sample rate triplets reported by
* the device. The problem is that we need to parse whole array first to
* get to know how many sample rates we have to expect.
@@ -319,6 +365,11 @@ static int parse_uac2_sample_rate_range(struct snd_usb_audio *chip,
!s1810c_valid_sample_rate(fp, rate))
goto skip_rate;
+ /* Filter out invalid rates on Focusrite devices */
+ if (USB_ID_VENDOR(chip->usb_id) == 0x1235 &&
+ !focusrite_valid_sample_rate(chip, fp, rate))
+ goto skip_rate;
+
if (fp->rate_table)
fp->rate_table[nr_rates] = rate;
if (!fp->rate_min || rate < fp->rate_min)