linux-kernel - RE: rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w

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Message-ID: <VE1PR04MB66873BEBB6EBCC1C04D0AC238FAC0@VE1PR04MB6687.eurprd04.prod.outlook.com>
Date:   Thu, 15 Aug 2019 18:01:22 +0000
From:   Leo Li <leoyang.li@....com>
To:     Biwen Li <biwen.li@....com>,
        "a.zummo@...ertech.it" <a.zummo@...ertech.it>,
        "alexandre.belloni@...tlin.com" <alexandre.belloni@...tlin.com>
CC:     "linux-rtc@...r.kernel.org" <linux-rtc@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w



> -----Original Message-----
> From: Biwen Li
> Sent: Wednesday, August 14, 2019 11:15 PM
> To: Leo Li <leoyang.li@....com>; a.zummo@...ertech.it;
> alexandre.belloni@...tlin.com
> Cc: linux-rtc@...r.kernel.org; linux-kernel@...r.kernel.org
> Subject: RE: rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w
> 
> > > Subject: rtc: pcf85363/pcf85263: fix error that failed to run
> > > hwclock -w
> > >
> > > Issue:
> > >     # hwclock -w
> > >     hwclock: RTC_SET_TIME: Invalid argument
> > >
> > > The patch fixes error when run command hwclock -w with rtc
> > > pcf85363/pcf85263
> >
> > Can you explain a little bit more in the commit message on how the
> changes fix
> > the above issue?   It is not that clear just from the code.
> 1. Relative patch: https://lkml.org/lkml/2019/4/3/55 , this patch will always
> check for unwritable registers, it will compare reg with max_register in
> regmap_writeable.
> 
> 2. In drivers/rtc/rtc-pcf85363.c, CTRL_STOP_EN is 0x2e, but DT_100THS is 0,
> max_regiter is 0x2f, then reg will be equal to 0x30, '0x30 < 0x2f' is false,so
> regmap_writeable will return false.

>From you description, it looks like the problem is actually that the buf[] was written to a wrong place.  If that's the case, we should say that in the commit message.

> 
> >
> > >
> > > Signed-off-by: Biwen Li <biwen.li@....com>
> > > ---
> > >  drivers/rtc/rtc-pcf85363.c | 7 ++++++-
> > >  1 file changed, 6 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
> > > index a075e77617dc..3450d615974d 100644
> > > --- a/drivers/rtc/rtc-pcf85363.c
> > > +++ b/drivers/rtc/rtc-pcf85363.c
> > > @@ -166,7 +166,12 @@ static int pcf85363_rtc_set_time(struct device
> > > *dev, struct rtc_time *tm)
> > >  	buf[DT_YEARS] = bin2bcd(tm->tm_year % 100);
> > >
> > >  	ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN,
> > > -				tmp, sizeof(tmp));
> > > +				tmp, 2);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	ret = regmap_bulk_write(pcf85363->regmap, DT_100THS,
> > > +				buf, sizeof(tmp) - 2);
> > >  	if (ret)
> > >  		return ret;
> > >
> > > --
> > > 2.17.1