Messages in this thread | | | Date | Wed, 21 May 2014 13:52:32 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [PATCH 02/10] xhci: 'noxhci_port_switch' kernel parameter |
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On Wed, 21 May 2014, Dan Williams wrote:
> On Tue, May 20, 2014 at 11:31 PM, Greg KH <gregkh@linuxfoundation.org> wrote: > > On Tue, May 20, 2014 at 11:21:03PM -0700, Dan Williams wrote: > >> On Tue, May 20, 2014 at 5:27 PM, Greg KH <gregkh@linuxfoundation.org> wrote: > >> >> Greg, > >> >> > >> >> Sorry, I don't think it is fair to users to force them to re-compile > >> >> their kernel to get their device to work. > >> > > >> > I totally agree. > >> > > >> >> Granted, I'm new to USB > >> >> development, but the rate of reports of endpoint devices that mess up > >> >> and require quirks in the hcd-driver or usb-core seems un-ending to > >> >> me. So, I don't think it is fair to expect that the tide of quirky > >> >> devices will be stemmed in any reasonable amount of time. Having a > >> >> "works with noxhci_port_switch" report from users is good data (hmm, I > >> >> think a printk to tell users to file a report upstream if the option > >> >> resolves their issue is needed). > >> > > >> > How about just adding a debugfs file instead? That way, once you fix > >> > this, we can then remove it and no one will care. > >> > >> The only thing stopping me from saying "deal." is that this darn > >> things is presently a pci quirk. So it happens well before the user > >> has a chance to manually override it with a debugfs file. > > > > Then have the debugfs file disconnect the device and reconnect it. > > We also need to reload the ehci hcd driver since it needs to know its > port count at load time as well. Which is more violent and error > prone than I think we want.
Does the port count change? Maybe nothing needs to be unloaded or reloaded. Has anyone tried it?
Alan Stern
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