* Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> [200306 19:05]:
> On Fri, Feb 28, 2020 at 10:02:43AM -0800, Tony Lindgren wrote:
> > In addition to handling errata i689 for idle with state, we must also
> > check for lost key up interrupts on fast key presses.
> >
> > For example rapidly pressing shift-shift-j can sometimes produce a J
> > instead of j. Let's fix the issue by scanning the keyboard in two
> > phases. First we scan for any key up events that we may have missed,
> > and then we scan for key down events.
> >
> > Cc: Arthur Demchenkov <spinal.by@xxxxxxxxx>
> > Cc: Merlijn Wajer <merlijn@xxxxxxxxxx>
> > Cc: Pavel Machek <pavel@xxxxxx>
> > Cc: Sebastian Reichel <sre@xxxxxxxxxx>
> > Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> > ---
> > drivers/input/keyboard/omap4-keypad.c | 48 ++++++++++++++++++---------
> > 1 file changed, 32 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/input/keyboard/omap4-keypad.c b/drivers/input/keyboard/omap4-keypad.c
> > --- a/drivers/input/keyboard/omap4-keypad.c
> > +++ b/drivers/input/keyboard/omap4-keypad.c
> > @@ -109,6 +109,34 @@ static void kbd_write_irqreg(struct omap4_keypad *keypad_data,
> > keypad_data->base + keypad_data->irqreg_offset + offset);
> > }
> >
> > +static void omap4_keypad_scan_state(struct omap4_keypad *keypad_data,
> > + unsigned char *key_state,
> > + bool down)
> > +{
> > + struct input_dev *input_dev = keypad_data->input;
> > + unsigned int col, row, code, changed;
> > + bool key_down;
> > +
> > + for (row = 0; row < keypad_data->rows; row++) {
> > + changed = key_state[row] ^ keypad_data->key_state[row];
> > + if (!changed)
> > + continue;
> > +
> > + for (col = 0; col < keypad_data->cols; col++) {
> > + if (changed & (1 << col)) {
>
>
> Looking at all too this, key state is 64 bit value, so if we make it a
> bitmap and use "for_each_set_bit()" we can simplify this scanning code.
OK good idea, I'll take a look.
Regards,
Tony
