On Sun, Nov 05, 2017 at 03:28:09PM +0200, Andy Shevchenko wrote: > On Fri, Nov 3, 2017 at 5:07 PM, Guillaume Douézan-Grard > <gdouezangrard@xxxxxxxxx> wrote: > > On Fri, Nov 03, 2017 at 02:50:52PM +0200, Andy Shevchenko wrote: > >> On Sun, Oct 29, 2017 at 1:53 AM, Guillaume Douézan-Grard > >> <gdouezangrard@xxxxxxxxx> wrote: > >> > Topstar U931 laptops provide an LED synced with the WLAN adapter > >> > hard-blocking state. Unfortunately, some models seem to be defective, > >> > making impossible to hard-block the adapter with the WLAN switch and > >> > thus the LED is useless. > >> > > >> > An ACPI method is available to programmatically control this switch and > >> > it indirectly allows to control the LED. > >> > > >> > This commit registers the LED within the corresponding subsystem, making > >> > possible for instance to use an rfkill-based trigger to synchronize the > >> > LED with the soft-blocking state. > >> > > >> > This feature is disabled by default and can be enabled with the > >> > `led_workaround` module parameter. > >> > >> > #include <linux/platform_device.h> > >> > #include <linux/input.h> > >> > #include <linux/input/sparse-keymap.h> > >> > +#include <linux/leds.h> > >> > >> Yep, exact place, esp. after moving platform_device to the right place. > >> > >> > +static bool led_workaround; > >> > +module_param_named(led_workaround, led_workaround, bool, 0444); > >> > +MODULE_PARM_DESC(led_workaround, > >> > + "Enables software-based WLAN LED control on systems with defective hardware switch"); > >> > >> So, this is most problematic piece in the series. > >> > >> We are not encouraging module parameters. Why do we need one? Can't be > >> detected automatically (perhaps based on DMI strings)? > > > > Darren told me that. > > > I tried to answer this question in the cover letter: > > Perhaps it makes sense to put this explanation in the commit message. > > > "These are barebone laptops, sold under quite a lot of brands and > > configurations, with different firmwares and so on. I can only say for sure > > that this issue is present for all the models sold under a specific brand, > > that's why I'm reluctant to enable this by default with a DMI check." > > > > In my case for instance, the DMI info has not been filled in by the retailler > > since I only have the ODM base board information to identify a model. > > I see. I would like to have a consensus on this one with Darren, the > rest (after addressing comments) looks good to me. If you can definitively say that all models of brand X and this HID have this quirk, that is considerably better than a lot of quirks we deal with today. I suggest doing that and holding off on the option. If it gets to the point where a number otherwise unidentifiable systems have this problem, we can add the option then. -- Darren Hart VMware Open Source Technology Center
