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authorJason Gerecke <killertofu@gmail.com>2017-01-26 09:06:22 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-02-09 08:02:46 +0100
commit8b51676d6cd9720c61089c6c7fb1914e2045576d (patch)
tree38bc226f3d2dfcec468ed3e608ada88a52c24eb0 /drivers
parentb3c8c31ed24c39f9a9fb9bee1e42b16640ff0bee (diff)
HID: wacom: Fix poor prox handling in 'wacom_pl_irq'
commit 282e4637bc1c0b338708bcebd09d31c69abec070 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/hid/wacom_wac.c28
1 files changed, 15 insertions, 13 deletions
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 5c02d7bbc7f2..35e3fd9fadf6 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -148,19 +148,21 @@ 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;
-
- 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));
+ 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_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;