redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

HID: wacom: Fix poor prox handling in 'wacom_pl_irq' 

Commit 025bcc1 performed cleanup work on the 'wacom_pl_irq' function, making
it follow the standards used in the rest of the codebase. The change
unintiontionally allowed the function to send input events from reports
that are not marked as being in prox. This can cause problems as the
report values for X, Y, etc. are not guaranteed to be correct. In
particular, occasionally the tablet will send a report with these values
set to zero. If such a report is received it can caus an unexpected jump
in the XY position.

This patch surrounds more of the processing code with a proximity check,
preventing these zeroed reports from overwriting the current state. To
be safe, only the tool type and ABS_MISC events should be reported when
the pen is marked as being out of prox.

Fixes: 025bcc1540 ("HID: wacom: Simplify 'wacom_pl_irq'")
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
hifive-unleashed-5.1
Jason Gerecke 2017-01-26 09:06:22 -08:00 committed by Jiri Kosina
parent a9ce7856ca
commit 282e4637bc
1 changed files with 13 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
drivers/hid/wacom_wac.c
View File

@ -166,19 +166,21 @@ static int wacom_pl_irq(struct wacom_wac *wacom)
wacom->id[0] = STYLUS_DEVICE_ID;
}
pressure = (signed char)((data[7] << 1) | ((data[4] >> 2) & 1));
if (features->pressure_max > 255)
pressure = (pressure << 1) | ((data[4] >> 6) & 1);
pressure += (features->pressure_max + 1) / 2;
if (prox) {
pressure = (signed char)((data[7] << 1) | ((data[4] >> 2) & 1));
if (features->pressure_max > 255)
pressure = (pressure << 1) | ((data[4] >> 6) & 1);
pressure += (features->pressure_max + 1) / 2;
input_report_abs(input, ABS_X, data[3] | (data[2] << 7) | ((data[1] & 0x03) << 14));
input_report_abs(input, ABS_Y, data[6] | (data[5] << 7) | ((data[4] & 0x03) << 14));
input_report_abs(input, ABS_PRESSURE, pressure);
input_report_abs(input, ABS_X, data[3] | (data[2] << 7) | ((data[1] & 0x03) << 14));
input_report_abs(input, ABS_Y, data[6] | (data[5] << 7) | ((data[4] & 0x03) << 14));
input_report_abs(input, ABS_PRESSURE, pressure);
input_report_key(input, BTN_TOUCH, data[4] & 0x08);
input_report_key(input, BTN_STYLUS, data[4] & 0x10);
/* Only allow the stylus2 button to be reported for the pen tool. */
input_report_key(input, BTN_STYLUS2, (wacom->tool[0] == BTN_TOOL_PEN) && (data[4] & 0x20));
input_report_key(input, BTN_TOUCH, data[4] & 0x08);
input_report_key(input, BTN_STYLUS, data[4] & 0x10);
/* Only allow the stylus2 button to be reported for the pen tool. */
input_report_key(input, BTN_STYLUS2, (wacom->tool[0] == BTN_TOOL_PEN) && (data[4] & 0x20));
}
if (!prox)
wacom->id[0] = 0;