On Wed, Oct 07, 2015 at 09:34:10AM -0400, Benjamin Tissoires wrote: > [sorry for the late answer Jiri, I was on vacations last week] > > On Oct 07 2015 or thereabouts, Mika Westerberg wrote: > > 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@xxxxxxxxxx> > > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > > --- > > Added check for MT_CLS_WIN_8 so that the fix is only done for real Win8 > > devices. > > I think we are good now. I would just like to have Seth or Andrew giving > a tested-by for Windows precision touchpads that can be found on the Dell > laptops. > > If the buttonpad property is set correctly, this is: > Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> This is working fine on my XPS 13 9343. Tested-by: Seth Forshee <seth.forshee@xxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
