Add patch to fix XPS 13 touchpad issue (rhbz 1123584)

1 files changed, 105 insertions, 0 deletions

diff --git a/HID-rmi-check-sanity-of-incoming-report.patch b/HID-rmi-check-sanity-of-incoming-report.patch
new file mode 100644
index 000000000..f3d0b6e08
--- /dev/null
+++ b/HID-rmi-check-sanity-of-incoming-report.patch
@@ -0,0 +1,105 @@
+From 5b65c2a0296644dd3dbdd590d6f00174d18c96b3 Mon Sep 17 00:00:00 2001
+From: Benjamin Tissoires <benjamin.tissoires@redhat.com>
+Date: Wed, 10 Sep 2014 18:02:37 -0700
+Subject: HID: rmi: check sanity of the incoming report
+
+In the Dell XPS 13 9333, it appears that sometimes the bus get confused
+and corrupts the incoming data. It fills the input report with the
+sentinel value "ff". Synaptics told us that such behavior does not comes
+from the touchpad itself, so we filter out such reports here.
+
+Unfortunately, we can not simply discard the incoming data because they
+may contain useful information. Most of the time, the misbehavior is
+quite near the end of the report, so we can still use the valid part of
+it.
+
+Fixes:
+https://bugzilla.redhat.com/show_bug.cgi?id=1123584
+
+Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
+Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
+Signed-off-by: Jiri Kosina <jkosina@suse.cz>
+
+diff --git a/drivers/hid/hid-rmi.c b/drivers/hid/hid-rmi.c
+index 8389e81..3cccff7 100644
+--- a/drivers/hid/hid-rmi.c
++++ b/drivers/hid/hid-rmi.c
+@@ -320,10 +320,7 @@ static int rmi_f11_input_event(struct hid_device *hdev, u8 irq, u8 *data,
+ 	int offset;
+ 	int i;
+ 
+-	if (size < hdata->f11.report_size)
+-		return 0;
+-
+-	if (!(irq & hdata->f11.irq_mask))
++	if (!(irq & hdata->f11.irq_mask) || size <= 0)
+ 		return 0;
+ 
+ 	offset = (hdata->max_fingers >> 2) + 1;
+@@ -332,9 +329,19 @@ static int rmi_f11_input_event(struct hid_device *hdev, u8 irq, u8 *data,
+ 		int fs_bit_position = (i & 0x3) << 1;
+ 		int finger_state = (data[fs_byte_position] >> fs_bit_position) &
+ 					0x03;
++		int position = offset + 5 * i;
++
++		if (position + 5 > size) {
++			/* partial report, go on with what we received */
++			printk_once(KERN_WARNING
++				"%s %s: Detected incomplete finger report. Finger reports may occasionally get dropped on this platform.\n",
++				 dev_driver_string(&hdev->dev),
++				 dev_name(&hdev->dev));
++			hid_dbg(hdev, "Incomplete finger report\n");
++			break;
++		}
+ 
+-		rmi_f11_process_touch(hdata, i, finger_state,
+-				&data[offset + 5 * i]);
++		rmi_f11_process_touch(hdata, i, finger_state, &data[position]);
+ 	}
+ 	input_mt_sync_frame(hdata->input);
+ 	input_sync(hdata->input);
+@@ -352,6 +359,11 @@ static int rmi_f30_input_event(struct hid_device *hdev, u8 irq, u8 *data,
+ 	if (!(irq & hdata->f30.irq_mask))
+ 		return 0;
+ 
++	if (size < (int)hdata->f30.report_size) {
++		hid_warn(hdev, "Click Button pressed, but the click data is missing\n");
++		return 0;
++	}
++
+ 	for (i = 0; i < hdata->gpio_led_count; i++) {
+ 		if (test_bit(i, &hdata->button_mask)) {
+ 			value = (data[i / 8] >> (i & 0x07)) & BIT(0);
+@@ -412,9 +424,29 @@ static int rmi_read_data_event(struct hid_device *hdev, u8 *data, int size)
+ 	return 1;
+ }
+ 
++static int rmi_check_sanity(struct hid_device *hdev, u8 *data, int size)
++{
++	int valid_size = size;
++	/*
++	 * On the Dell XPS 13 9333, the bus sometimes get confused and fills
++	 * the report with a sentinel value "ff". Synaptics told us that such
++	 * behavior does not comes from the touchpad itself, so we filter out
++	 * such reports here.
++	 */
++
++	while ((data[valid_size - 1] == 0xff) && valid_size > 0)
++		valid_size--;
++
++	return valid_size;
++}
++
+ static int rmi_raw_event(struct hid_device *hdev,
+ 		struct hid_report *report, u8 *data, int size)
+ {
++	size = rmi_check_sanity(hdev, data, size);
++	if (size < 2)
++		return 0;
++
+ 	switch (data[0]) {
+ 	case RMI_READ_DATA_REPORT_ID:
+ 		return rmi_read_data_event(hdev, data, size);
+-- 
+cgit v0.10.1
+