HID: wacom: generic: read HID_DG_CONTACTMAX from any feature report

BugLink: https://bugs.launchpad.net/bugs/1845266
commit 184eccd40389df29abefab88092c4ff33191fd0c upstream.

In the generic code path, HID_DG_CONTACTMAX was previously
only read from the second byte of report 0x23.

Another report (0x82) has the HID_DG_CONTACTMAX in the
higher nibble of the third byte. We should support reading the
value of HID_DG_CONTACTMAX no matter what report we are reading
or which position that value is in.

To do this we submit the feature report as a event report
using hid_report_raw_event(). Our modified finger event path
records the value of HID_DG_CONTACTMAX when it sees that usage.

Fixes: 8ffffd5212846 ("HID: wacom: fix timeout on probe for some wacoms")
Signed-off-by: Aaron Armstrong Skomra <aaron.skomra@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index 3e8288f0c84bdcb3582c6b723bf07313f54bfaf4..a97f6ddf6e4bc9ca0343048c583e588a1ab2128b 100644 (file)
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -125,14 +125,16 @@ static void wacom_feature_mapping(struct hid_device *hdev,
                /* leave touch_max as is if predefined */
                if (!features->touch_max) {
                        /* read manually */
-                       data = kzalloc(2, GFP_KERNEL);
+                       n = hid_report_len(field->report);
+                       data = hid_alloc_report_buf(field->report, GFP_KERNEL);
                        if (!data)
                                break;
                        data[0] = field->report->id;
                        ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
-                                               data, 2, WAC_CMD_RETRIES);
-                       if (ret == 2) {
-                               features->touch_max = data[1];
+                                              data, n, WAC_CMD_RETRIES);
+                       if (ret == n) {
+                               ret = hid_report_raw_event(hdev,
+                                       HID_FEATURE_REPORT, data, n, 0);
                        } else {
                                features->touch_max = 16;
                                hid_warn(hdev, "wacom_feature_mapping: "

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 27e5bbd06f69d3e8c2f78e5857ee62e9155d0f8f..446afa7cb4f8b2a1d920ad5925862b9d75b9542e 100644 (file)
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -2440,6 +2440,7 @@ static void wacom_wac_finger_event(struct hid_device *hdev,
        struct wacom *wacom = hid_get_drvdata(hdev);
        struct wacom_wac *wacom_wac = &wacom->wacom_wac;
        unsigned equivalent_usage = wacom_equivalent_usage(usage->hid);
+       struct wacom_features *features = &wacom->wacom_wac.features;
 
        switch (equivalent_usage) {
        case HID_GD_X:
@@ -2460,6 +2461,9 @@ static void wacom_wac_finger_event(struct hid_device *hdev,
        case HID_DG_TIPSWITCH:
                wacom_wac->hid_data.tipswitch = value;
                break;
+       case HID_DG_CONTACTMAX:
+               features->touch_max = value;
+               return;
        }