On Tue, Jul 07, 2009 at 11:33:36AM -0400, Alan Stern wrote: > Greg: > > A lot of the USB serial drivers call usb_clear_halt in their open > methods. Are these calls really needed? Hm, at least one was, in the whiteheat driver, I don't know about the others, it might just have been copied around :( > There are comments about this in several of the drivers, particularly > whiteheat. Most of them boil down to "work around HCD bugs". As far > as anyone knows there are no remaining bugs of this sort in the HCDs > -- and if there were, it would be better to fix them instead of working > around them. Those HCD bugs were usually from a different operating system, so the devices had wierd workarounds themselves to handle this. Hopefully those issues are also resolved in those operating systems now as well. I have no problem taking them out where you think that they are not needed, and seeing what happens. Especially for things like the option driver where it fixes real problems. > Another possibility has to do with firmware changes, but I don't see > how a firmware update could require a bunch of clear-halts for bulk > endpoints. > > The cypress_m8 driver also calls usb_clear_halt from within its > completion routines, which is definitely wrong. Yeah, that looks odd. thanks, greg k-h -- 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
