linux-kernel - Re: [PATCH 1/2] dt-bindings: watchdog: mediatek,mtk-wdt: add MT7988 watchdog and toprgu

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: <a56cfe76-ab03-4187-b6f1-04a5c3414e64@linaro.org>
Date:   Fri, 10 Nov 2023 15:46:14 +0100
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Daniel Golle <daniel@...rotopia.org>
Cc:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        Wim Van Sebroeck <wim@...ux-watchdog.org>,
        Guenter Roeck <linux@...ck-us.net>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        linux-watchdog@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org
Subject: Re: [PATCH 1/2] dt-bindings: watchdog: mediatek,mtk-wdt: add MT7988
 watchdog and toprgu

On 10/11/2023 15:40, Daniel Golle wrote:
> On Fri, Nov 10, 2023 at 03:20:53PM +0100, Krzysztof Kozlowski wrote:
>> On 10/11/2023 15:17, Daniel Golle wrote:
>>> On Fri, Nov 10, 2023 at 12:56:18PM +0100, AngeloGioacchino Del Regno wrote:
>>>> Il 10/11/23 01:30, Daniel Golle ha scritto:
>>>>> Add binding description for mediatek,mt7988-wdt.
>>>>>
>>>>> Signed-off-by: Daniel Golle <daniel@...rotopia.org>
>>>>> ---
>>>>>   .../bindings/watchdog/mediatek,mtk-wdt.yaml          |  1 +
>>>>>   include/dt-bindings/reset/mediatek,mt7988-resets.h   | 12 ++++++++++++
>>>>>   2 files changed, 13 insertions(+)
>>>>>   create mode 100644 include/dt-bindings/reset/mediatek,mt7988-resets.h
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml b/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
>>>>> index cc502838bc398..8d2520241e37f 100644
>>>>> --- a/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
>>>>> +++ b/Documentation/devicetree/bindings/watchdog/mediatek,mtk-wdt.yaml
>>>>> @@ -25,6 +25,7 @@ properties:
>>>>>             - mediatek,mt6735-wdt
>>>>>             - mediatek,mt6795-wdt
>>>>>             - mediatek,mt7986-wdt
>>>>> +          - mediatek,mt7988-wdt
>>>>>             - mediatek,mt8183-wdt
>>>>>             - mediatek,mt8186-wdt
>>>>>             - mediatek,mt8188-wdt
>>>>> diff --git a/include/dt-bindings/reset/mediatek,mt7988-resets.h b/include/dt-bindings/reset/mediatek,mt7988-resets.h
>>>>> new file mode 100644
>>>>> index 0000000000000..fa7c937505e08
>>>>> --- /dev/null
>>>>> +++ b/include/dt-bindings/reset/mediatek,mt7988-resets.h
>>>>> @@ -0,0 +1,12 @@
>>>>> +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
>>>>> +
>>>>> +/* TOPRGU resets */
>>>>
>>>> The first reset is zero, the second reset is one.
>>>>
>>>> Where's the zero'th reset? :-)
>>>
>>> Currently the reset numbers represent the corresponding bit positions in
>>> the toprgu register, as this is how the mtk-wdt driver is organized.
>>>
>>> So there is probably something at bit 0, and also at bit 3~11 and
>>> maybe also 17~23, but it's unknown and may be added later once known
>>> and/or needed.
>>
>> There is no need to put register bits, which are not used by the driver,
>> in the bindings.
> 
> There aren't. That's why there isn't a zero'th reset (and also not 3~11, 17~24).
> 
> Or should the driver be reorganized to provide a mapping of logical to
> physical resets, and then have only the needed once present and start
> counting logical resets from 0? This is doable, of course, but it's a
> bit of effort just for the aesthetical goal of starting to count from
> zero and continous in header file.
> 
> And, of course, chances are that other currently still unused bits
> will be needed at a later point which then would mean having to add
> them in at least 2 places (header file and mapping logical<->physical)
> where as currently it would just mean adding a line defining it in the
> header file.

You can do it, but it's not what I wrote here. So bear with me:

"There is no need to put register bits in the bindings."

You replied "There aren't", which I don't understand in this context. I
can be clearer:
Drop this hunk.

> 
> A quick looks at all the other headers in
> include/dt-binding/reset/mt*-resets.h also shows that currently all of
> them have unused bits and e.g. infracfg on MT7986 starts counting from
> 6.

Best regards,
Krzysztof