On Wed, 6 Dec 2006, Dmitry Torokhov wrote: > On 12/6/06, Alan Stern <[EMAIL PROTECTED]> wrote: > > > > +static int hid_kvm_present; > > +module_param_named(kvm, hid_kvm_present, bool, 0444); > > +MODULE_PARM_DESC(kvm, "Ignore errors caused by a KVM"); > > + > > If we do that I think 0644 is better as it will allow users to "fix" > their keyboard wothout rebooting.
Okay. > > /* > > * Register a new report for a device. > > */ > > @@ -1070,6 +1074,15 @@ static void hid_irq_in(struct urb *urb) > > case -EILSEQ: /* protocol error or unplug */ > > case -EPROTO: /* protocol error or unplug */ > > case -ETIME: /* protocol error or unplug */ > > + /* > > + * Many KVMs break the data pathway between the > > + * host and the device at various times (some do so > > + * even when the switch is set to connect the host > > + * to the device). If one of these things is being > > + * used then we need to ignore transmission errors. > > + */ > > + if (hid_kvm_present) > > + break; > > When would happen if we always ignore these errors? Why can't we > always ignore them? We used to do that. Then there was a Bugzilla report in which some device would occasionally hang and need to be reset. The symptom was that the errors would occur, because the device would not respond to packets. In general I think it's more correct to pay attention to I/O errors and try to repair them than to ignore them. After all, with any reasonable device these errors do indicate a genuine problem. But with KVM switches we don't have any choice. When you get right down to it, they break the USB protocol. Alan Stern ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
