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2013-04-03ALSA: usb: Work around CM6631 sample rate change bugTorstein Hegge1-10/+35
The C-Media CM6631 USB receiver doesn't respond to changes in sample rate while the interface is active. The same behavior is observed in other UAC2 hardware like the VIA VT1731. Reset the interface after setting the sampling frequency on sample rate changes, to ensure that the sample rate set by snd_usb_init_sample_rate() is used. Otherwise, the device will try to use the sample rate of the previous stream, causing distorted sound on sample rate changes. The reset is performed for all UAC2 devices, as it should not affect a standards compliant device, but it is only necessary for C-Media CM6631, VIA VT1731 and possibly others. Failure to read sample rate from the device is not handled as an error in set_sample_rate_v2(), as (permanent or intermittent) failure to read sample rate isn't essential for a successful sample rate set. Signed-off-by: Torstein Hegge <hegge@resisty.net> Acked-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2012-08-01ALSA: snd-usb: fix clock source validity indexDaniel Mack1-1/+2
uac_clock_source_is_valid() uses the control selector value to access the bmControls bitmap of the clock source unit. This is wrong, as control selector values start from 1, while the bitmap uses all available bits. In other words, "Clock Validity Control" is stored in D3..2, not D5..4 of the clock selector unit's bmControls. Signed-off-by: Daniel Mack <zonque@gmail.com> Reported-by: Andreas Koch <andreas@akdesigninc.com> Cc: stable@kernel.org Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-09-27ALSA: usb-audio: increase control transfer timeoutClemens Ladisch1-6/+6
There are certain devices that are reportedly so slow that they need more than 100 ms to handle control transfers. Therefore, increase the timeout in mixer(_quirks).c to 1000 ms. The timeout parameter of snd_usb_ctl_msg() is now constant, so we can drop it. Reported-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-05-18ALSA: usb-audio: assume valid clockDaniel Mack1-1/+10
If the interface can't report a clock's validity, assume that it's valid. Signed-off-by: Daniel Mack <zonque@gmail.com> Reported-by: Vicente Joel <vicentejoel@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-09-03ALSA: usb-audio: fix detection of vendor-specific device protocol settingsClemens Ladisch1-2/+1
The Audio Class v2 support code in 2.6.35 added checks for the bInterfaceProtocol field. However, there are devices (usually those detected by vendor-specific quirks) that do not have one of the predefined values in this field, which made the driver reject them. To fix this regression, restore the old behaviour, i.e., assume that a device with an unknown bInterfaceProtocol field (other than UAC_VERSION_2) has more or less UAC-v1-compatible descriptors. [compile warning fixes by tiwai] Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: Daniel Mack <daniel@caiaq.de> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-07-09ALSA: usb-audio: silence a superfluous warningClemens Ladisch1-4/+1
It is not advisable to print a warning when a device does not support setting the sample rate because this is perfectly valid for devices with a single rate or where rates are implicitly changed by selecting another alternate setting. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-06-23ALSA: usb-audio: simplify control interface accessDaniel Mack1-13/+9
As the control interface is now carried in struct snd_usb_audio, we can simplify the API a little and also drop the private ctrlif field from struct usb_mixer_interface. Also remove a left-over function prototype in pcm.h. Signed-off-by: Daniel Mack <daniel@caiaq.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-06-23ALSA: usb-audio: move and add some commentsDaniel Mack1-2/+14
Also add a list of open topics. Signed-off-by: Daniel Mack <daniel@caiaq.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-06-23ALSA: usb-audio: clean up includes in clock.cDaniel Mack1-15/+1
Signed-off-by: Daniel Mack <daniel@caiaq.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-06-11ALSA: usb-audio: fix control messages for USB_RECIP_INTERFACEDaniel Mack1-4/+8
Control messages directed to an interface must have the interface number set in the lower 8 bits of wIndex. This wasn't done correctly for some clock and mixer messages. Signed-off-by: Daniel Mack <daniel@caiaq.de> Reported-by: Alex Lee <alexlee188@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-05-31ALSA: usb-audio: parse clock topology of UAC2 devicesDaniel Mack1-0/+311
Audio devices which comply to the UAC2 standard can export complex clock topologies in its descriptors and set up links between them. The entities that are defined are - clock sources, which define the end-leafs. - clock selectors, which act as switch to select one out of many possible clocks sources. - clock multipliers, which have an input clock source, and act as clock source again. They can be used to derive one clock from another. All sample rate changes, clock validity queries and the like must go to clock source elements, while clock selectors and multipliers can be used as terminal clock source. The following patch adds a parser for these elements and functions to iterate over the tree and find the leaf nodes (clock sources). The samplerate set functions were moved to the new clock.c file. Signed-off-by: Daniel Mack <daniel@caiaq.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>