Messages in this thread | | | Subject | Re: [PATCHv3 2/4] usb: gadget: replace "is_dualspeed" with "max_speed" | From | "Michal Nazarewicz" <> | Date | Wed, 24 Aug 2011 16:53:52 +0200 |
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> On Wed, 24 Aug 2011, Michal Nazarewicz wrote: >> I'm actually wondering whether we really need to worry about it. >> composite_driver has the “max_speed” field and I would just leave it as >> composite driver's author responsibility to put correct value there. >> >> One thing that could be worth doing is iterate over all the >> configurations and figure out if at least one supports the speed >> declared by “max_speed” and if not, lower it.
On Wed, 24 Aug 2011 16:31:27 +0200, Alan Stern <stern@rowland.harvard.edu> wrote: > That's the same as what I said: Use the highest speed supported by any > function driver.
Right.
>> Like I've said before, as additional functionality, composite.c could >> check if it's USB_SPEED_UNKWONW in which case it would look for the >> lowest speed that all the functions support.
> It's reasonable. Just be sure to document it properly; otherwise > nobody will understand or remember it!
I've found where my reasoning was faulty. The usb_gadget_driver's max_speed is set before all the functions get added so composite.c has no way to figure those things in advance. That's why we need to relay on usb_composite_driver's max_speed be set to a proper value.
-- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michal "mina86" Nazarewicz (o o) ooo +-----<email/xmpp: mnazarewicz@google.com>-----ooO--(_)--Ooo-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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