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Subject: Re: [PATCH v2 3/3] pinctrl: pinctrl-single: fix pcs_pin_dbg_show() when
 bits_per_mux != 0
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
CC:     Tony Lindgren <tony@atomide.com>,
        Haojian Zhuang <haojian.zhuang@linaro.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        "David Woodhouse" <dwmw@amazon.co.uk>, <benh@amazon.com>,
        <ronenk@amazon.com>, <talel@amazon.com>, <jonnyc@amazon.com>,
        <hanochu@amazon.com>, <tgershi@amazon.com>,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
References: <20210316202434.27555-1-hhhawa@amazon.com>
 <20210316202434.27555-4-hhhawa@amazon.com>
 <CAHp75VdVnFn+DuO54PsUVGk4ZWWCJpYKsSQVsaUkiDzZki2QRQ@mail.gmail.com>
From:   "Hawa, Hanna" <hhhawa@amazon.com>
Message-ID: <c2dc25d8-b71c-e6c2-4c36-3d82bd0f762f@amazon.com>
Date:   Wed, 17 Mar 2021 21:35:19 +0200
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On 3/17/2021 2:27 PM, Andy Shevchenko wrote:
> 
> On Tue, Mar 16, 2021 at 11:24 PM Hanna Hawa <hhhawa@amazon.com> wrote:
>>
>> An SError was detected when trying to print the supported pins in a
> 
> What SError is?

System error:
[   24.257831] SError Interrupt on CPU0, code 0xbf000002 -- SError
...
[   24.257855] Kernel panic - not syncing: Asynchronous SError Interrupt

> 
>> pinctrl device which supports multiple pins per register. This change
>> fixes the pcs_pin_dbg_show() in pinctrl-single driver when
>> bits_per_mux != 0. In addition move offset calculation and pin offset in
> 
> '!= 0' -> 'is not zero'

Will be fixed.

> 
>> register to common function.
> 
> Fixes tag?

Sure, will be added.

> 
>> Signed-off-by: Hanna Hawa <hhhawa@amazon.com>
>> ---
>>   drivers/pinctrl/pinctrl-single.c | 66 ++++++++++++++++++++++----------
>>   1 file changed, 45 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
>> index f3394517cb2e..434f90c8b1b3 100644
>> --- a/drivers/pinctrl/pinctrl-single.c
>> +++ b/drivers/pinctrl/pinctrl-single.c
>> @@ -270,20 +270,53 @@ static void __maybe_unused pcs_writel(unsigned val, void __iomem *reg)
>>          writel(val, reg);
>>   }
>>
>> +static unsigned int pcs_pin_reg_offset_get(struct pcs_device *pcs,
>> +                                          unsigned int pin)
>> +{
>> +       unsigned int offset, mux_bytes;
> 
> Offset can be replaced by direct return statements.

Ack.

> 
>> +       mux_bytes = pcs->width / BITS_PER_BYTE;
>> +
>> +       if (pcs->bits_per_mux) {
>> +               unsigned int pin_offset_bytes;
>> +
>> +               pin_offset_bytes = (pcs->bits_per_pin * pin) / BITS_PER_BYTE;
>> +               offset = (pin_offset_bytes / mux_bytes) * mux_bytes;
>> +       } else {
>> +               offset = pin * mux_bytes;
>> +       }
>> +
>> +       return offset;
>> +}
>> +
>> +static unsigned int pcs_pin_shift_reg_get(struct pcs_device *pcs,
>> +                                         unsigned int pin)
>> +{
>> +       return ((pin % (pcs->width / pcs->bits_per_pin)) * pcs->bits_per_pin);
> 
> Too many parentheses.

Will remove the extra parentheses.

> 
>> +}
>> +
>>   static void pcs_pin_dbg_show(struct pinctrl_dev *pctldev,
>>                                          struct seq_file *s,
>>                                          unsigned pin)
>>   {
>>          struct pcs_device *pcs;
>> -       unsigned val, mux_bytes;
>> +       unsigned int val;
>>          unsigned long offset;
>>          size_t pa;
>>
>>          pcs = pinctrl_dev_get_drvdata(pctldev);
>>
>> -       mux_bytes = pcs->width / BITS_PER_BYTE;
>> -       offset = pin * mux_bytes;
>> -       val = pcs->read(pcs->base + offset);
>> +       offset = pcs_pin_reg_offset_get(pcs, pin);
>> +
>> +       if (pcs->bits_per_mux) {
>> +               unsigned int pin_shift_in_reg = pcs_pin_shift_reg_get(pcs, pin);
> 
>> +               val = pcs->read(pcs->base + offset)
>> +                       & (pcs->fmask << pin_shift_in_reg);
> 
> One line?
> At least move & to the upper line.
> 
>> +       } else {
>> +               val = pcs->read(pcs->base + offset);
> 
> It's the same as in above branch, why not
> 
> val = read();
> if ()
>   val &= fmask << _reg_get(...);
> 
> ?

Agree, looks better

Thanks Andy, will send new patchset soon.

Thanks,
Hanna