Commit fee906f0 authored by Mika Westerberg's avatar Mika Westerberg Committed by Greg Kroah-Hartman

HID: multitouch: Fetch feature reports on demand for Win8 devices

commit 6d4f5440 upstream.

Some newer Intel Skylake based Dell laptops with Win8 precision touchpad
fail when initial feature reports are fetched from it. Below is an example
output with some additional debug included:

 i2c_hid i2c-DLL0704:01: Fetching the HID descriptor
 i2c_hid i2c-DLL0704:01: __i2c_hid_command: cmd=20 00
 i2c_hid i2c-DLL0704:01: HID Descriptor: 1e 00 00 01 99 02 21 00 24 ...
 ...
 i2c_hid i2c-DLL0704:01: i2c_hid_get_report
 i2c_hid i2c-DLL0704:01: __i2c_hid_command: cmd=22 00 38 02 23 00
 i2c_hid i2c-DLL0704:01: report (len=4): 04 00 08 05
 i2c_hid i2c-DLL0704:01: report id 13
 i2c_hid i2c-DLL0704:01: i2c_hid_get_report
 i2c_hid i2c-DLL0704:01: __i2c_hid_command: cmd=22 00 3d 02 23 00
 i2c_hid i2c-DLL0704:01: failed to retrieve report from device.
 i2c_hid i2c-DLL0704:01: report id 7
 i2c_hid i2c-DLL0704:01: i2c_hid_get_report
 i2c_hid i2c-DLL0704:01: __i2c_hid_command: cmd=22 00 37 02 23 00
 i2c_hid i2c-DLL0704:01: report (len=259): 03 01 07 fc 28 fe 84 40 ...
 i2c_hid i2c-DLL0704:01: report id 4
 i2c_hid i2c-DLL0704:01: i2c_hid_get_report
 i2c_hid i2c-DLL0704:01: __i2c_hid_command: cmd=22 00 34 02 23 00

We manage to fetch few reports but then the touchpad dies:

 i2c_designware i2c_designware.1: i2c_dw_handle_tx_abort: lost arbitration
 i2c_hid i2c-DLL0704:01: failed to retrieve report from device.

it eventually pulls the whole I2C bus low:

 i2c_designware i2c_designware.1: controller timed out
 i2c_hid i2c-DLL0704:01: failed to set a report to device.

Fix this by preventing initial feature report retrieval for Win8 devices.
Instead we fetch reports as needed in mt_feature_mapping(). This prevents
fetching reports which might cause problems with the device in question.
Suggested-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: default avatarSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4a8e6c9f
...@@ -309,6 +309,41 @@ static struct attribute_group mt_attribute_group = { ...@@ -309,6 +309,41 @@ static struct attribute_group mt_attribute_group = {
.attrs = sysfs_attrs .attrs = sysfs_attrs
}; };
static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
{
struct mt_device *td = hid_get_drvdata(hdev);
int ret, size = hid_report_len(report);
u8 *buf;
/*
* Only fetch the feature report if initial reports are not already
* been retrieved. Currently this is only done for Windows 8 touch
* devices.
*/
if (!(hdev->quirks & HID_QUIRK_NO_INIT_REPORTS))
return;
if (td->mtclass.name != MT_CLS_WIN_8)
return;
buf = hid_alloc_report_buf(report, GFP_KERNEL);
if (!buf)
return;
ret = hid_hw_raw_request(hdev, report->id, buf, size,
HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
if (ret < 0) {
dev_warn(&hdev->dev, "failed to fetch feature %d\n",
report->id);
} else {
ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf,
size, 0);
if (ret)
dev_warn(&hdev->dev, "failed to report feature\n");
}
kfree(buf);
}
static void mt_feature_mapping(struct hid_device *hdev, static void mt_feature_mapping(struct hid_device *hdev,
struct hid_field *field, struct hid_usage *usage) struct hid_field *field, struct hid_usage *usage)
{ {
...@@ -327,6 +362,8 @@ static void mt_feature_mapping(struct hid_device *hdev, ...@@ -327,6 +362,8 @@ static void mt_feature_mapping(struct hid_device *hdev,
break; break;
case HID_DG_CONTACTMAX: case HID_DG_CONTACTMAX:
mt_get_feature(hdev, field->report);
td->maxcontact_report_id = field->report->id; td->maxcontact_report_id = field->report->id;
td->maxcontacts = field->value[0]; td->maxcontacts = field->value[0];
if (!td->maxcontacts && if (!td->maxcontacts &&
...@@ -343,6 +380,7 @@ static void mt_feature_mapping(struct hid_device *hdev, ...@@ -343,6 +380,7 @@ static void mt_feature_mapping(struct hid_device *hdev,
break; break;
} }
mt_get_feature(hdev, field->report);
if (field->value[usage->usage_index] == MT_BUTTONTYPE_CLICKPAD) if (field->value[usage->usage_index] == MT_BUTTONTYPE_CLICKPAD)
td->is_buttonpad = true; td->is_buttonpad = true;
...@@ -1026,8 +1064,13 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id) ...@@ -1026,8 +1064,13 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
* reports. Fortunately, the Win8 spec says that all touches * reports. Fortunately, the Win8 spec says that all touches
* should be sent during each report, making the initialization * should be sent during each report, making the initialization
* of input reports unnecessary. * of input reports unnecessary.
*
* In addition some touchpads do not behave well if we read
* all feature reports from them. Instead we prevent
* initial report fetching and then selectively fetch each
* report we are interested in.
*/ */
hdev->quirks |= HID_QUIRK_NO_INIT_INPUT_REPORTS; hdev->quirks |= HID_QUIRK_NO_INIT_REPORTS;
td = devm_kzalloc(&hdev->dev, sizeof(struct mt_device), GFP_KERNEL); td = devm_kzalloc(&hdev->dev, sizeof(struct mt_device), GFP_KERNEL);
if (!td) { if (!td) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment