RE: [PATCH 1/2] Input: edt-ft5x06 - use get_unaligned_be16()

[David Laight <David.Laight@ACULAB.COM>]

From: Andy Shevchenko
> Sent: 25 June 2019 11:50
> To: David Laight
> Cc: Dmitry Torokhov; linux-input@vger.kernel.org; Marco Felsch; Benoit Parrot; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH 1/2] Input: edt-ft5x06 - use get_unaligned_be16()
> 
> On Tue, Jun 25, 2019 at 11:44 AM David Laight <David.Laight@aculab.com> wrote:
> >
> > From: Dmitry Torokhov
> > > Sent: 23 June 2019 07:32
> > >
> > > Instead of doing conversion by hand, let's use the proper accessors.
> > >
> > > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > > ---
> > >  drivers/input/touchscreen/edt-ft5x06.c | 5 +++--
> > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> > > index c639ebce914c..ec770226e119 100644
> > > --- a/drivers/input/touchscreen/edt-ft5x06.c
> > > +++ b/drivers/input/touchscreen/edt-ft5x06.c
> > > @@ -27,6 +27,7 @@
> > >  #include <linux/gpio/consumer.h>
> > >  #include <linux/input/mt.h>
> > >  #include <linux/input/touchscreen.h>
> > > +#include <asm/unaligned.h>
> > >
> > >  #define WORK_REGISTER_THRESHOLD              0x00
> > >  #define WORK_REGISTER_REPORT_RATE    0x08
> > > @@ -239,8 +240,8 @@ static irqreturn_t edt_ft5x06_ts_isr(int irq, void *dev_id)
> > >               if (tsdata->version == EDT_M06 && type == TOUCH_EVENT_DOWN)
> > >                       continue;
> > >
> > > -             x = ((buf[0] << 8) | buf[1]) & 0x0fff;
> > > -             y = ((buf[2] << 8) | buf[3]) & 0x0fff;
> > > +             x = get_unaligned_be16(buf) & 0x0fff;
> > > +             y = get_unaligned_be16(buf + 2) & 0x0fff;
> >
> > You might as well delete the pointless masking with 0xff.
> 
> Hmm... Does it guarantee the most significant nibble to be always 0?
> (Note 16-bit value and three f:s in the mask)

Sorry, I misread it :-(

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)