On Mon, Jun 01, 2015 at 02:32:13PM -0700, Dmitry Torokhov wrote:
> On Mon, Jun 01, 2015 at 11:22:26PM +0200, Maxime Ripard wrote:
> > Hi Dmitry,
> >
> > On Mon, Jun 01, 2015 at 10:47:30AM -0700, Dmitry Torokhov wrote:
> > > On Mon, Jun 01, 2015 at 05:21:11PM +0200, Pavel Machek wrote:
> > > >
> > > >
> > > > > > > > The 3eea8b5d68c801fec788b411582b803463834752 is just bad.
> > > > > > >
> > > > > > > You were very welcome to review this patch at the time and/or suggest
> > > > > > > a fix that pleases everyone.
> > > > > >
> > > > > > You should be the one that should suggest fixes, as you broke it in
> > > > > > the first place. But clearly you don't understand that.
> > > > >
> > > > > You actually never asked for a fix, and went head first calling this
> > > > > patch "bad" and asking for nothing but reverting it.
> > > >
> > > > Date: Fri, 29 May 2015 21:08:16 +0200
> > > > Subject: 4.1 touchscreen regression on n900 -- pinpointed [was Re:
> > > > linux-n900
> > > > ...
> > > > Maxime, can you suggest a fix?
> > >
> > > How about we do something like below (it needs a small edt-ft5x06 fixup
> > > that I'll send separately). Not tested.
> > >
> > > Thanks.
> > >
> > > --
> > > Dmitry
> > >
> > >
> > > Input: improve parsing OF parameters for touchscreens
> > >
> > > From: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > >
> > > When applying touchscreen parameters specified in device tree let's make
> > > sure we keep whatever setup was done by the driver and not reset the
> > > missing values to zero.
> > >
> > > Reported-by: Pavel Machek <pavel@xxxxxx>
> > > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > > ---
> > > drivers/input/touchscreen/edt-ft5x06.c | 2 -
> > > drivers/input/touchscreen/of_touchscreen.c | 67 ++++++++++++++++++----------
> > > drivers/input/touchscreen/tsc2005.c | 2 -
> > > include/linux/input/touchscreen.h | 5 +-
> > > 4 files changed, 48 insertions(+), 28 deletions(-)
> > >
> > > diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> > > index 29d179a..394b1de 100644
> > > --- a/drivers/input/touchscreen/edt-ft5x06.c
> > > +++ b/drivers/input/touchscreen/edt-ft5x06.c
> > > @@ -1041,7 +1041,7 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
> > > 0, tsdata->num_y * 64 - 1, 0, 0);
> > >
> > > if (!pdata)
> > > - touchscreen_parse_of_params(input);
> > > + touchscreen_parse_of_params(input, true);
> > >
> > > error = input_mt_init_slots(input, MAX_SUPPORT_POINTS, INPUT_MT_DIRECT);
> > > if (error) {
> > > diff --git a/drivers/input/touchscreen/of_touchscreen.c b/drivers/input/touchscreen/of_touchscreen.c
> > > index b82b520..c132624 100644
> > > --- a/drivers/input/touchscreen/of_touchscreen.c
> > > +++ b/drivers/input/touchscreen/of_touchscreen.c
> > > @@ -14,14 +14,22 @@
> > > #include <linux/input/mt.h>
> > > #include <linux/input/touchscreen.h>
> > >
> > > -static u32 of_get_optional_u32(struct device_node *np,
> > > - const char *property)
> > > +static bool touchscreen_get_property_u32(struct device_node *np,
> > > + const char *property,
> > > + unsigned int default_value,
> > > + unsigned int *value)
> > > {
> > > u32 val = 0;
> > > + int error;
> > >
> > > - of_property_read_u32(np, property, &val);
> > > + error = of_property_read_u32(np, property, &val);
> > > + if (error) {
> > > + *value = default_value;
> > > + return false;
> > > + }
> > >
> > > - return val;
> > > + *value = val;
> > > + return true;
> >
> > This looks good.
> >
> > However, of_property_read_u32 already does the right thing here by not
> > update val if the property is not found.
>
> I know but it is not documented anywhere (as far as I know) so I'd
> rather not rely on the implementation detail that might change in the
> future. This is not a hot path so extra assignment should not hurt.
It is actually: http://lxr.free-electrons.com/source/drivers/of/base.c#L1231
But you're right that it's mostly a cosmetic change.
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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