HID: do not init input reports for Win 8 multitouch devices

Some multitouch screens do not like to be polled for input reports.
However, the Win8 spec says that all touches should be sent during
each report, making the initialization of reports unnecessary.
The Win7 spec is less precise, so do not use this for those devices.

Add the quirk HID_QUIRK_NO_INIT_INPUT_REPORTS so that we do not have to
introduce a quirk for each problematic device. This quirk makes the driver
behave the same way the Win 8 does. It actually retrieves the features,
but not the inputs.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Tested-by: Srinivas Pandruvada<srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index c28ef86..ac28f08 100644 (file)
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -951,6 +951,18 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
        hdev->quirks |= HID_QUIRK_MULTI_INPUT;
        hdev->quirks |= HID_QUIRK_NO_EMPTY_INPUT;
 
+       /*
+        * Handle special quirks for Windows 8 certified devices.
+        */
+       if (id->group == HID_GROUP_MULTITOUCH_WIN_8)
+               /*
+                * Some multitouch screens do not like to be polled for input
+                * reports. Fortunately, the Win8 spec says that all touches
+                * should be sent during each report, making the initialization
+                * of input reports unnecessary.
+                */
+               hdev->quirks |= HID_QUIRK_NO_INIT_INPUT_REPORTS;
+
        td = devm_kzalloc(&hdev->dev, sizeof(struct mt_device), GFP_KERNEL);
        if (!td) {
                dev_err(&hdev->dev, "cannot allocate multitouch data\n");

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 9941828..55ea9c4 100644 (file)
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -807,12 +807,17 @@ void usbhid_init_reports(struct hid_device *hid)
 {
        struct hid_report *report;
        struct usbhid_device *usbhid = hid->driver_data;
+       struct hid_report_enum *report_enum;
        int err, ret;
 
-       list_for_each_entry(report, &hid->report_enum[HID_INPUT_REPORT].report_list, list)
-               usbhid_submit_report(hid, report, USB_DIR_IN);
+       if (!(hid->quirks & HID_QUIRK_NO_INIT_INPUT_REPORTS)) {
+               report_enum = &hid->report_enum[HID_INPUT_REPORT];
+               list_for_each_entry(report, &report_enum->report_list, list)
+                       usbhid_submit_report(hid, report, USB_DIR_IN);
+       }
 
-       list_for_each_entry(report, &hid->report_enum[HID_FEATURE_REPORT].report_list, list)
+       report_enum = &hid->report_enum[HID_FEATURE_REPORT];
+       list_for_each_entry(report, &report_enum->report_list, list)
                usbhid_submit_report(hid, report, USB_DIR_IN);
 
        err = 0;

diff --git a/include/linux/hid.h b/include/linux/hid.h
index cef1e9b..bc132d2 100644 (file)
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -283,6 +283,7 @@ struct hid_item {
 #define HID_QUIRK_MULTI_INPUT                  0x00000040
 #define HID_QUIRK_HIDINPUT_FORCE               0x00000080
 #define HID_QUIRK_NO_EMPTY_INPUT               0x00000100
+#define HID_QUIRK_NO_INIT_INPUT_REPORTS                0x00000200
 #define HID_QUIRK_SKIP_OUTPUT_REPORTS          0x00010000
 #define HID_QUIRK_FULLSPEED_INTERVAL           0x10000000
 #define HID_QUIRK_NO_INIT_REPORTS              0x20000000