[PATCH v2] mfd: mt6370: Add the out-of-bound check to prevent the null pointer

[ChiYuan Huang]

Andy Shevchenko <andy.shevchenko at gmail.com> 於 2022年10月21日 週五 下午5:14寫道：
>
> On Fri, Oct 21, 2022 at 12:02 PM ChiYuan Huang <u0084500 at gmail.com> wrote:
> > Andy Shevchenko <andy.shevchenko at gmail.com> 於 2022年10月21日 週五 下午4:34寫道：
> > > On Fri, Oct 21, 2022 at 5:17 AM cy_huang <u0084500 at gmail.com> wrote:
>
> > > It looks like you randomly cut the trace.
> > > It's not what I meant and documentation suggests.
> > >
> > I checked the submitting-patch.rst.
> > To satisfy the requirement for 70-75 chars per line, I only keep the
> > important log.
> >
> > May I ask what you mean for the 'trim'?
> > Is it 'Still keep 70-75 per line and cut the characters that's over
> > the limit to the next line"?
>
> > > https://www.kernel.org/doc/html/latest/process/submitting-patches.html#backtraces-in-commit-messages
>
> Have you had a chance to read this section of the document?
>
OK, get it.
Is the below text enough to express this problem?

Ex. Testing as below (mt6370 register range from 0 to 0x1ff)
   rg_bound_show()
        regmap_raw_read(regmap, 0x200, &val, sizeof(val));

pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : i2c_smbus_xfer+0x58/0x120
lr : i2c_smbus_read_i2c_block_data+0x74/0xc0
Call trace:
 i2c_smbus_xfer+0x58/0x120
 i2c_smbus_read_i2c_block_data+0x74/0xc0
 mt6370_regmap_read+0x40/0x60
 _regmap_raw_read+0xe4/0x278
 regmap_raw_read+0xec/0x240
 rg_bound_show+0xb0/0x120
> --
> With Best Regards,
> Andy Shevchenko