linux-kernel - Re: [PATCH v3 6/7] gpio: exar: switch to using regmap

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <a5b0fcd0-eb62-79b3-3f27-6595b9bdb91c@siemens.com>
Date:   Tue, 10 Nov 2020 15:50:11 +0100
From:   Jan Kiszka <jan.kiszka@...mens.com>
To:     Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     Bartosz Golaszewski <brgl@...ev.pl>,
        Linus Walleij <linus.walleij@...aro.org>,
        David Laight <David.Laight@...lab.com>,
        linux-gpio <linux-gpio@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 6/7] gpio: exar: switch to using regmap


On 10.11.20 15:30, Bartosz Golaszewski wrote:
> On Tue, Nov 10, 2020 at 3:26 PM Andy Shevchenko
> <andriy.shevchenko@...ux.intel.com> wrote:
>>
>> On Tue, Nov 10, 2020 at 04:26:24PM +0200, Andy Shevchenko wrote:
>>> On Tue, Nov 10, 2020 at 01:34:05PM +0100, Bartosz Golaszewski wrote:
>>>> From: Bartosz Golaszewski <bgolaszewski@...libre.com>
>>>>
>>>> We can simplify the code in gpio-exar by using regmap. This allows us to
>>>> drop the mutex (regmap provides its own locking) and we can also reuse
>>>> regmap's bit operations instead of implementing our own update function.
>>>
>>> ...
>>>
>>>> +   /*
>>>> +    * We don't need to check the return values of mmio regmap operations (unless
>>>> +    * the regmap has a clock attached which is not the case here).
>>>> +    */
>>>> +   exar_gpio->regs = devm_regmap_init_mmio(dev, p, &exar_regmap_config);
>>>> +   if (IS_ERR(exar_gpio->regs))
>>>> +           return PTR_ERR(exar_gpio->regs);
>>>>
>>>>     index = ida_alloc(&ida_index, GFP_KERNEL);
>>>> -   if (index < 0) {
>>>> -           ret = index;
>>>> -           goto err_mutex_destroy;
>>>> -   }
>>>> +   if (index < 0)
>>>> +           return index;
>>>
>>> And below you effectively use p as regmap!
>>> That's what renaming of variable regs -> regmap or map can easily reveal.
>>>
>>>       exar_gpio->regs = p;
>>
>> Jan, if you remove this line, does it help?
>>
> 
> Ha! I guess you were right saying that keeping the name is asking for
> trouble then. :)
> 
> I think that may be it but address width should still be changed to 16.
> 

Removing the line that Andy found made things work here. And switching
to 16 for reg_bits didn't make things worse again.

Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux