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authorPavel Hofman <pavel.hofman@ivitera.com>2022-01-27 12:43:30 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-01-31 14:26:18 +0100
commit355a05dc8367d7533e5925e08dadfc8604961bbc (patch)
treefc5817c40e6af899aa9e80aac2fab28da2176f3b /Documentation
parentusb: gadget: audio: Add HS/SS bInterval params for UAC2 (diff)
downloadlinux-355a05dc8367d7533e5925e08dadfc8604961bbc.tar.xz
linux-355a05dc8367d7533e5925e08dadfc8604961bbc.zip
usb: gadget: f_uac2: Optionally determine bInterval for HS and SS
Allow setting configfs params p_hs_bint/c_hs_bint to 0. If they are set to 0, determine the largest bInterval (4 to 1) for which the required bandwidth of the max samplerate fits the max allowed packet size. If the required bandwidth exceeds max bandwidth for single-packet mode (ep->mc=1), keep bInterval at 1. The FS speed is left at fixed bInterval=1. If for any speed the required bandwidth exceeds the max bandwidth corresponding to the selected/determined bInterval, print a warning. Signed-off-by: Pavel Hofman <pavel.hofman@ivitera.com> Link: https://lore.kernel.org/r/20220127114331.41367-4-pavel.hofman@ivitera.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/configfs-usb-gadget-uac24
-rw-r--r--Documentation/usb/gadget-testing.rst4
2 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uac2 b/Documentation/ABI/testing/configfs-usb-gadget-uac2
index 33fb237b3ca5..3371c39f651d 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget-uac2
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uac2
@@ -8,7 +8,7 @@ Description:
c_chmask capture channel mask
c_srate list of capture sampling rates (comma-separated)
c_ssize capture sample size (bytes)
- c_hs_bint capture bInterval for HS/SS (1-4)
+ c_hs_bint capture bInterval for HS/SS (1-4: fixed, 0: auto)
c_sync capture synchronization type
(async/adaptive)
c_mute_present capture mute control enable
@@ -23,7 +23,7 @@ Description:
p_chmask playback channel mask
p_srate list of playback sampling rates (comma-separated)
p_ssize playback sample size (bytes)
- p_hs_bint playback bInterval for HS/SS (1-4)
+ p_hs_bint playback bInterval for HS/SS (1-4: fixed, 0: auto)
p_mute_present playback mute control enable
p_volume_present playback volume control enable
p_volume_min playback volume control min value
diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst
index bd91191683be..c6d034abce3a 100644
--- a/Documentation/usb/gadget-testing.rst
+++ b/Documentation/usb/gadget-testing.rst
@@ -734,7 +734,7 @@ The uac2 function provides these attributes in its function directory:
c_volume_min capture volume control min value (in 1/256 dB)
c_volume_max capture volume control max value (in 1/256 dB)
c_volume_res capture volume control resolution (in 1/256 dB)
- c_hs_bint capture bInterval for HS/SS (1-4)
+ c_hs_bint capture bInterval for HS/SS (1-4: fixed, 0: auto)
fb_max maximum extra bandwidth in async mode
p_chmask playback channel mask
p_srate list of playback sampling rates (comma-separated)
@@ -744,7 +744,7 @@ The uac2 function provides these attributes in its function directory:
p_volume_min playback volume control min value (in 1/256 dB)
p_volume_max playback volume control max value (in 1/256 dB)
p_volume_res playback volume control resolution (in 1/256 dB)
- p_hs_bint playback bInterval for HS/SS (1-4)
+ p_hs_bint playback bInterval for HS/SS (1-4: fixed, 0: auto)
req_number the number of pre-allocated request for both capture
and playback
function_name name of the interface