> -----Original Message-----
> From: Lukas Wunner [mailto:lu...@wunner.de]
> Sent: Wednesday, September 13, 2017 12:20 PM
> To: Limonciello, Mario <mario_limoncie...@dell.com>
> Cc: dvh...@infradead.org; LKML <linux-kernel@vger.kernel.org>;
> platform-driver-
> x...@vger.kernel.org; Richard Hughes <hughsi...@gmail.com>; Yehezkel Bernat
> <yehezkel...@gmail.com>; Mika Westerberg <mika.westerb...@linux.intel.com>
> Subject: Re: [PATCH v3] Add driver to force WMI Thunderbolt controller power
> status
>
> Sorry, late to the party.
>
> On Fri, Sep 08, 2017 at 10:23:11AM -0500, Mario Limonciello wrote:
> > + mode = hex_to_bin(buf[0]);
> > + if (mode == 0 || mode == 1) {
> > + status = wmi_evaluate_method(INTEL_WMI_THUNDERBOLT_GUID,
> 0, 1,
> > + &input, NULL);
> > + if (ACPI_FAILURE(status)) {
> > + pr_err("intel-wmi-thunderbolt: failed setting %s\n",
> > + buf);
> > + return -ENODEV;
> > + }
> > + } else {
> > + pr_err("intel-wmi-thunderbolt: unsupported mode: %d", mode);
> > + }
> > + return count;
> > +}
>
> Seems odd to allow user space to fill the log by writing invalid data
> to sysfs, likewise that success is returned in the else case.
> I'd drop both pr_err() and return -EINVAL in the else case.
>
Seems fine to me. As Darren already queued the patch, I'll send a follow up
patch
to fix these two cases.
>
> > +static const struct wmi_device_id intel_wmi_thunderbolt_id_table[] = {
> > + { .guid_string = INTEL_WMI_THUNDERBOLT_GUID },
> > + { },
> > +};
>
> I'm not familiar with WMI, but don't you need a MODULE_DEVICE_TABLE here?
> How does user space know which module to load upon receiving the uevent?
Some macros for WMI bus devices.
https://github.com/torvalds/linux/blob/e0f25a3f2d052e36ff67a9b4db835c3e27e950d8/include/linux/wmi.h#L55
https://github.com/torvalds/linux/blob/master/include/linux/device.h#L1487
