Am Montag, 12. Juli 2010, 04:02:58 schrieb Alan Stern: > On Sun, 11 Jul 2010, Oliver Neukum wrote: > > > I am afraid this is not quite the case. If the device was just opened and closed, > > the normal heuristics make sense. If the device reports that no medium is present, > > you should suspend at once. > > In theory, yes. But how many programs continue to hold the device file > open after they learn that no medium is present? And do so without > sending more transfer requests? None that I know of. But do they need to? It seems to me that the normal polling will continously open/close devices are a rate comparable to the standard time the heuristics uses. Now we could shift this to user space, but I doubt we'd get it in in a reasonable time frame. And I believe this is a feature we could use in the long run. > > Besides, you surely must agree that this patch is a tremendous layering > violation. If we really want to allow autosuspend under the > circumstances just described, the right place to do it is in the SCSI > disk driver. You are obviously right. I'd say the code makes sense but it is in the wrong place. Regards Oliver -- 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
