* Felipe Balbi <[EMAIL PROTECTED]> [070529 16:34]:
> <snip>
>
>> > The behavioral difference would be that WHEN ("not 'IF'")
>> > the whitelist (which is very easily checked against product
>> > documentation) diverges from the list of configured drivers
>> > (no easy way to crosscheck that and docs) things would not
>> > act the same.
>>
>> I guess HNP should be offered for peripherals even if not
>> on whitelist, but only peripherals on whitelist (with HNP
>> or not) should be allowed.
>
> Or maybe we run a set_feature (b_hnp_enabled) just before the
> suspend... can we do that dave?? It doesn't seem really correct when
> typing... but...
>
> If I'm not wrong... every device can accept a b_hnp_enable set_feature
> command... if the controller doesn't support it just return a
> "stall".. or something like that... so... we could just forget about
> the whitelist for now.. can't we?
>
> If the device supports HNP it will get the b_hnp_enable command and
> after a_host enters in suspend mode... it will try to do HNP (if the
> user wants...)AFAIK, all OTG devices need to support b_hnp_enable, but it's just a way to tell it that host supports HNP, it does not mean HNP should enabled. Enabling HNP should be done by the user on the b-device. >> > This is more or less what you were trying to achieve, >> > yes? But it leads to surprising behavior in cases >> > like: >> > >> > * hook up non-OTG peripheral #1 ... acts just >> > the way you'd normally expect >> > >> > * hook up OTG peripheral #2 ... surprise! it >> > refuses to act as a peripheral at first. >> > >> > The "principle of least astonishment" argues that >> > the "peripheral #1" model should be followed for >> > as long as possible. Customer service calls would >> > be a lot simpler too... >> >> Yeh I guess in that case it needs to wait for autosuspend >> until #1 is done. >> >> But if #2 is not on whitelist and can do HNP, then >> it just gets rejected and never gets it's HNP opportunity. >> >> Hmmm... I guess the non-whitelisted b-device should sit waiting for HNP mode start when the host autosuspend suspends the bus? Tony ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
