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

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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: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Mika Westerberg 2015-10-07 15:33:43 +03:00 committed by Jiri Kosina
parent dc425a1c8c
commit 6d4f5440a3
1 changed files with 44 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
drivers/hid/hid-multitouch.c
View File

@ -309,6 +309,41 @@ static struct attribute_group mt_attribute_group = {
.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,
struct hid_field *field, struct hid_usage *usage)
{
@ -327,6 +362,8 @@ static void mt_feature_mapping(struct hid_device *hdev,
break;
case HID_DG_CONTACTMAX:
mt_get_feature(hdev, field->report);
td->maxcontact_report_id = field->report->id;
td->maxcontacts = field->value[0];
if (!td->maxcontacts &&
@ -343,6 +380,7 @@ static void mt_feature_mapping(struct hid_device *hdev,
break;
}
mt_get_feature(hdev, field->report);
if (field->value[usage->usage_index] == MT_BUTTONTYPE_CLICKPAD)
td->is_buttonpad = true;
@ -1029,8 +1067,13 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
* reports. Fortunately, the Win8 spec says that all touches
* should be sent during each report, making the initialization
* 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);
if (!td) {