Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Wed, 15 Jul 2020 13:44:01 +0200 | Subject | Re: [PATCH 09/13] cpufreq: acpi-cpufreq: Remove unused ID structs |
| |
On Wed, Jul 15, 2020 at 1:34 PM Lee Jones <lee.jones@linaro.org> wrote: > > On Wed, 15 Jul 2020, Rafael J. Wysocki wrote: > > > On Wed, Jul 15, 2020 at 5:27 AM Viresh Kumar <viresh.kumar@linaro.org> wrote: > > > > > > On 15-07-20, 08:54, Viresh Kumar wrote: > > > > On 14-07-20, 22:03, Lee Jones wrote: > > > > > On Tue, 14 Jul 2020, Rafael J. Wysocki wrote: > > > > > > > > > > > On Tue, Jul 14, 2020 at 4:51 PM Lee Jones <lee.jones@linaro.org> wrote: > > > > > > > > > > > > > > Can't see them being used anywhere and the compiler doesn't complain > > > > > > > that they're missing, so ... > > > > > > > > > > > > Aren't they needed for automatic module loading in certain configurations? > > > > > > > > > > Any idea how that works, or where the code is for that? > > > > > > > > The MODULE_DEVICE_TABLE() thingy creates a map of vendor-id, > > > > product-id that the kernel keeps after boot (and so there is no static > > > > reference of it for the compiler), later when a device is hotplugged > > > > into the kernel it refers to the map to find the related driver for it > > > > and loads it if it isn't already loaded. > > > > > > > > This has some of it, search for MODULE_DEVICE_TABLE() in it. > > > > Documentation/driver-api/usb/hotplug.rst > > > > > > And you just need to add __maybe_unused to them to suppress the > > > warning. > > > > Wouldn't that cause the compiler to optimize them away if it doesn't > > see any users? > > It looks like they're only unused when !MODULE,
OK
> in which case optimising them away would be the correct thing to do, no?
| |