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authorMika Westerberg <mika.westerberg@linux.intel.com>2015-10-07 14:33:43 +0200
committerJiri Kosina <jkosina@suse.cz>2015-10-12 00:49:19 +0200
commit6d4f5440a3a2bb2e9d0d582bbf98234e9e9bb095 (patch)
tree2dddc9cb6e7edb926ffc9d088c9bc344c3051ff2 /Documentation/ABI
parentHID: multitouch: Add suffix for HID_DG_TOUCHPAD (diff)
downloadlinux-6d4f5440a3a2bb2e9d0d582bbf98234e9e9bb095.tar.xz
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HID: multitouch: Fetch feature reports on demand for Win8 devices
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>
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