is there a reason "usbhid.quirks" parameter is not root writable?

Valdis.Kletnieks at Valdis.Kletnieks at
Thu Nov 12 20:02:00 EST 2015

On Thu, 12 Nov 2015 16:44:35 -0800, Greg KH said:
> On Thu, Nov 12, 2015 at 03:15:41AM -0700, Robert P. J. Day wrote:

> > module_param_array_named(quirks, quirks_param, charp, NULL, 0444);
> > MODULE_PARM_DESC(quirks, "Add/modify USB HID quirks by specifying "

> You can add a runtime quirk to the device itself when it shows up in
> sysfs for the hid driver.  Use that instead of the module parameter for
> that specific device.

That's a workaround.  Still unexplained is why it's mode 0444 for "add/modify".

But to answer Robert's question:  I suspect that it's mode 0444 so you can
read the current list, but changing the list after modprobe time is for
some reason problematic.  Having said that, I admit I haven't looked at
the source deep enough to find the exact reason. It's probably something
subtle, because simply adding an ID to a list of IDs shouldn't be that
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