[U-Boot] [Patch V3] i2c: mxc: add a condition in case the parameter is NULL

[Qianyu Gong]

Hi Stefano,

Could you please help to merge this patch? Thanks very much.

Regards,
Qianyu

> -----Original Message-----
> From: Qianyu Gong
> Sent: Monday, December 21, 2015 1:42 PM
> To: hs at denx.de; Gong Qianyu-B52263 <Qianyu.Gong at freescale.com>
> Cc: u-boot at lists.denx.de; Stefano Babic <sbabic at denx.de>
> Subject: RE: [U-Boot] [Patch V3] i2c: mxc: add a condition in case the parameter is
> NULL
> 
> 
> 
> > -----Original Message-----
> > From: Heiko Schocher [mailto:hs at denx.de]
> > Sent: Friday, December 18, 2015 6:24 PM
> > To: Gong Qianyu-B52263
> > Cc: u-boot at lists.denx.de; Stefano Babic
> > Subject: Re: [U-Boot] [Patch V3] i2c: mxc: add a condition in case the
> > parameter is NULL
> >
> > Hello Gong Qianyu,
> >
> > added Stefano Babic to cc as he is the imx maintainer.
> >
> > Am 18.12.2015 um 10:38 schrieb Gong Qianyu:
> > > This could avoid executing the code that only applies to i.MX platforms.
> > >
> > > The bus_i2c_init() is called before relocation and will assgin value
> > > to a static variable. If U-Boot is then still running in a flash
> > > device, it's theoretically not allowed to write data to flash
> > > without an erasing operation. For i.MX platforms, the U-Boot is
> > > always running in DDR.
> > >
> > > Actually it causes asynchronous error when the ARM64 system error
> > > report is enabled and the flash write protect is set.
> > >
> > > Signed-off-by: Gong Qianyu <Qianyu.Gong at freescale.com>
> > > ---
> > > V3:
> > >   - Sorry..Remove an unrelated line in other file.
> > >
> > >   drivers/i2c/mxc_i2c.c | 12 ++++++++++--
> > >   1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > Ok, from my side, but it would be better to switch your board(s) to
> > support DM and get rid of this old stuff from this driver.
> >
> > Reviewed-by: Heiko Schocher <hs at denx.de>
> >
> > bye,
> > Heiko
> 
> Thanks. But I have no control over this driver. Maybe they are considering to
> convert it later.
> 
> Regards,
> Qianyu
> 
> > >
> > > diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c index
> > > fa4c82f..b2d15c9 100644
> > > --- a/drivers/i2c/mxc_i2c.c
> > > +++ b/drivers/i2c/mxc_i2c.c
> > > @@ -581,8 +581,16 @@ void bus_i2c_init(int index, int speed, int unused,
> > >   		return;
> > >   	}
> > >
> > > -	mxc_i2c_buses[index].idle_bus_fn = idle_bus_fn;
> > > -	mxc_i2c_buses[index].idle_bus_data = idle_bus_data;
> > > +	/*
> > > +	 * Warning: Be careful to allow the assignment to a static
> > > +	 * variable here. This function could be called while U-Boot is
> > > +	 * still running in flash memory. So such assignment is equal
> > > +	 * to write data to flash without erasing.
> > > +	 */
> > > +	if (idle_bus_fn)
> > > +		mxc_i2c_buses[index].idle_bus_fn = idle_bus_fn;
> > > +	if (idle_bus_data)
> > > +		mxc_i2c_buses[index].idle_bus_data = idle_bus_data;
> > >
> > >   	ret = enable_i2c_clk(1, index);
> > >   	if (ret < 0) {
> > >
> >
> > --
> > DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
> > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany