On Tue, Jan 24, 2017 at 8:37 AM, Lukáš Lalinský <lukas@xxxxxxxxxx> wrote: > On Tue, Jan 24, 2017 at 8:32 AM, Oliver Neukum <oneukum@xxxxxxxx> wrote: >> Am Montag, den 23.01.2017, 19:36 +0100 schrieb Lukáš Lalinský: >>> I have uploaded both captures here - >>> https://gist.github.com/lalinsky/83148a827d5cd43e79e377d8e1b5ed0d >> >> Indeed it is does not set a configuration. Either the capture >> is incomplete or device and host violate the standard. A device >> may be left unconfigured. > > Is this may or may not? I'm not familiar with USB, so I assumed if > there is only one configuration and there is always one active, it > does not need to be set explicitly because the correct one is already > active. > >> We need to read the descriptors even if we >> see only one configuration to get the power budgeting right. > > Aren't those in the CONFIGURATION descriptors? Reading the STRING > descriptor is probably only useful if you need to print the > configuration details somewhere. I re-ran the capture on a Windows 7 host. The previous capture was missing data, probably due to interactions of the Linux host and Windows VM. https://gist.github.com/lalinsky/2ec7d74b049b448b1f7032d8861ca4a2 It does set the configuration, but does not request the string descriptor. Lukas -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
