On Thu, Feb 03, 2005 at 10:56:05AM -0500, Alan Stern wrote: > Basically the situation is this: There's a config option for usb-storage
USB_STORAGE_RW_DETECT - a bad idea - it must not be necessary to recompile the kernel (or at least usb-storage) when encountering a bad device. Many users get their kernels from elsewhere and are unable to compile. > to select whether or not the driver should allow checking for > write-protection on new devices. The majority of devices support this > check with no difficulty, but there are a few that choke on it. (That's > part of the reason we made it configurable -- the other part is that > earlier versions of Linux performed the check in a slightly different way > which was much more likely to cause problems.) > > Now there's a proposal to make this be a module parameter rather than a > config option, so that it can be changed on-the-fly via sysfs without > having to rebuild usb-storage. A big improvement. > The bad aspect of doing this is that it > would also eliminate the nice explanatory help message in the Kconfig > file, so the background information wouldn't be so easily available to > users any more. Kernel configuration time is not the time to feed users with information. There are thousands of parameters. A parameter is a sign of weakness: I have no idea how to make this work, please figure it out for yourself. > Suggested actions are: > > Move the explanation into the FAQ on www.linux-usb.org (a good > idea in any case). Not least of the advantages is that it would > then be findable by Google. Yes. > Change the setting to a module parameter, and _keep_ the config > option -- but make the config option control only the initial > default value of the parameter. No. The config option is bad. You yourself have to determine the initial default value. Imagine a distribution. They have to do something for thousands of users, many of whom are unable to compile kernels. If it regularly happens that RW investigation leads to a hang, and there is a great variety of devices where this happens, then do not investigate RW. If only two devices are known that are bad, mark them in unusual_devs.h and make the default to determine RW, with a module parameter to override for new unknown bad cases. Nobody is in a better position to determine the default than you are. > Go ahead and do the complete changeover now (or as soon as the > FAQ is updated). Yes. > P.S.: This raises the issue of documenting a bunch of module parameters > added to the USB subsystem fairly recently. What's the best way to do > this? Add entries to Documentation/kernel-parameters.txt? Put > descriptions on the linux-usb FAQ? Both? Both. kernel-parameters.txt is obligatory, all other places are nice. Andries ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
