platform/x86: intel-wmi-thunderbolt: Add dynamic debugging

Some users have been reporting issues with thunderbolt being turned off
before fully initialized. This is suspected to be caused by userspace
turning off the Thunderbolt controller using intel-wmi-thunderbolt
prematurely.

Userspace has already made some mitigations for this situation:
https://github.com/hughsie/fwupd/commit/ef6f1d76983c9b66
https://github.com/hughsie/fwupd/commit/c07ce5b4889a5384

To allow easier debugging of this situation add output that can be turned
on with dynamic debugging to better root cause this problem.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199631
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=201227
Suggested-by: Mika Westerberg <mika.westerberg@intel.com>
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/platform/x86/intel-wmi-thunderbolt.c b/drivers/platform/x86/intel-wmi-thunderbolt.c
index b029a70b084aa1b3da98471f36d72da095aea3aa..9ded8e2af312f23293a5a6a8a56a3c7b8d499c3e 100644 (file)
--- a/drivers/platform/x86/intel-wmi-thunderbolt.c
+++ b/drivers/platform/x86/intel-wmi-thunderbolt.c
@@ -30,12 +30,16 @@ static ssize_t force_power_store(struct device *dev,
        input.length = sizeof(u8);
        input.pointer = &mode;
        mode = hex_to_bin(buf[0]);
+       dev_dbg(dev, "force_power: storing %#x\n", mode);
        if (mode == 0 || mode == 1) {
                status = wmi_evaluate_method(INTEL_WMI_THUNDERBOLT_GUID, 0, 1,
                                             &input, NULL);
-               if (ACPI_FAILURE(status))
+               if (ACPI_FAILURE(status)) {
+                       dev_dbg(dev, "force_power: failed to evaluate ACPI method\n");
                        return -ENODEV;
+               }
        } else {
+               dev_dbg(dev, "force_power: unsupported mode\n");
                return -EINVAL;
        }
        return count;