On Fri, 3 Aug 2007, Matthew Garrett wrote: > This patch is exactly that - a way of getting most of the benefits of > autosuspend without any real probability of breaking hardware. If you > mean "Are the distributions willing to pop up dialogs asking users to > start caring about obscure aspects of the USB spec", then I don't think > that's actually making things better.
Quite aside from issues involving desktop ease-of-use and distribution intentions, there is a technical matter to consider. With the default autosuspend timeout set to 2 seconds, as it is now, it can often happen that userspace isn't able to respond in time to prevent a device from being suspended. At bootup especially, the system is so busy running lots of tasks that response to a newly-detected device can be delayed for tens of seconds. Even loading the device driver's module can take so long that the device gets autosuspended first. There are two possible solutions, both involving the kernel (since userspace can't respond in time). One is to change the default timeout to something larger, or even disable it completely. Then people would need to rely on userspace tools to enable autosuspend on known-good devices. The other possibility is to have a fairly reliable blacklist or whitelist and again rely on userspace to manage edge cases. This is of course more flexible than a blanket default setting, but it's still pretty rigid. On the other hand, a blacklist can't be changed without rebuilding the kernel whereas the default timeout can be adjusted on the boot command line. I don't know what the "best" approach is, but I can't see any alternative to these two. Furthermore, whatever approach we settle on _has_ to be able to handle devices which simply die upon being suspended. Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
