usbmode: add config #0 and delay before actual config

I have a Huawei ME909s-120.  When I switch directly from configuration
to go via configuration #0, and a short delay, and then to configuration
well. So in order to fix it, add config #0 and a 100milliseconds
delay before switching to actual config, like in USB_ModeSwitch.

References: https://www.draisberghof.de/usb_modeswitch/bb/viewtopic.php?f=4&t=2710&sid=505ed44b4064fef7009f0c26aac085e2&start=15
Signed-off-by: Henrik Ginstmark <henrik@ginstmark.se>
Signed-off-by: Petr Štetiar <ynezz@true.cz> [rebased, commit description facelift]

1 files changed, 4 insertions, 1 deletions

diff --git a/switch.c b/switch.c
index cc04237..6285c7c 100644
--- a/switch.c
+++ b/switch.c
@@ -520,8 +520,11 @@ void handle_switch(struct usbdev_data *data)
 
 		config_new = blobmsg_get_u32(tb[DATA_CONFIG]);
 		if (libusb_get_configuration(data->devh, &config) ||
-		    config != config_new)
+		    config != config_new) {
+			libusb_set_configuration(data->devh, 0);
+			usleep(100000);
 			libusb_set_configuration(data->devh, config_new);
+		}
 	}
 
 	if (tb[DATA_ALT]) {