diff options
| -rw-r--r-- | drivers/usb/core/generic.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c index 358ca8dd784f..72d1109f13eb 100644 --- a/drivers/usb/core/generic.c +++ b/drivers/usb/core/generic.c @@ -19,6 +19,8 @@ #include <linux/usb.h> #include <linux/usb/hcd.h> +#include <linux/usb/audio.h> +#include <linux/usb/audio-v3.h> #include "usb.h" static inline const char *plural(int n) @@ -40,6 +42,36 @@ static int is_activesync(struct usb_interface_descriptor *desc) && desc->bInterfaceProtocol == 1; } +static int usb_audio_max_rev_config(struct usb_host_bos *bos) +{ + int desc_cnt, func_cnt, numfunc; + int num_cfg_desc; + struct usb_config_summary_descriptor *conf_summary; + + if (!bos || !bos->config_summary) + goto done; + + conf_summary = bos->config_summary; + num_cfg_desc = bos->num_config_summary_desc; + + for (desc_cnt = 0; desc_cnt < num_cfg_desc; desc_cnt++) { + numfunc = conf_summary->bNumFunctions; + for (func_cnt = 0; func_cnt < numfunc; func_cnt++) { + /* look for BADD 3.0 */ + if (conf_summary->cs_info[func_cnt].bClass == + USB_CLASS_AUDIO && + conf_summary->cs_info[func_cnt].bProtocol == + UAC_VERSION_3 && + conf_summary->cs_info[func_cnt].bSubClass != + FULL_ADC_PROFILE) + return conf_summary->bConfigurationValue; + } + } + +done: + return -EINVAL; +} + int usb_choose_configuration(struct usb_device *udev) { int i; @@ -130,7 +162,6 @@ int usb_choose_configuration(struct usb_device *udev) best = c; break; } - /* If all the remaining configs are vendor-specific, * choose the first one. */ else if (!best) @@ -143,7 +174,10 @@ int usb_choose_configuration(struct usb_device *udev) insufficient_power, plural(insufficient_power)); if (best) { - i = best->desc.bConfigurationValue; + /* choose usb audio class preferred config if available */ + i = usb_audio_max_rev_config(udev->bos); + if (i < 0) + i = best->desc.bConfigurationValue; dev_dbg(&udev->dev, "configuration #%d chosen from %d choice%s\n", i, num_configs, plural(num_configs)); |