On Thu, Sep 13, 2012 at 10:39:36AM -0400, Alan Stern wrote: > On Wed, 12 Sep 2012, Sarah Sharp wrote: > > > I don't think unbinding the xHCI driver will switch the ports back to > > EHCI, unless xhci_shutdown is called when the driver is unbound, and > > Michal has the recent bug fix commit > > e95829f474f0db3a4d940cae1423783edd966027 "xhci: Switch PPT ports to EHCI > > on shutdown." > > Should this be changed? The ehci-hcd driver faces a similar situation; > it shares ports with companion UHCI/OHCI controllers. The ports are > switched over to EHCI at bind time and switched back during unbind. > > Without something like this, it's impossible to force the ports to > attach the lower-speed controller when you want, and it's impossible to > use the ports when the higher-speed driver isn't loaded. I really don't want the Intel port switchover to work like the EHCI companion controllers. It's really just a hardware hack to get around the lack of official Windows support, and I would really rather utilize it as little as possible. Supporting it has already been a giant pain in the neck, and for the last two release candidates, it seems like there's a patch or two fixing something broken with that code in every bug fix pull request I send Greg. Adding something similar to the EHCI companion controller switchover on module unload would just add further complexity. I would rather that the Intel xHCI systems work similar to a system with any other third party xHCI host controller: if you have the xHCI driver loaded, your ports work; if you don't have it loaded, it doesn't. Sarah Sharp -- 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
