linux-kernel - Re: [PATCH v1] i2c: tegra: Make timeout error more informative

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Message-ID: <017aad72-9872-a4aa-dc99-bd7d08c0db14@gmail.com>
Date:   Tue, 10 Mar 2020 16:26:41 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Wolfram Sang <wsa@...-dreams.de>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Laxman Dewangan <ldewangan@...dia.com>,
        linux-i2c@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] i2c: tegra: Make timeout error more informative

10.03.2020 14:37, Wolfram Sang пишет:
> On Mon, Mar 02, 2020 at 08:35:12PM +0300, Dmitry Osipenko wrote:
>> The I2C timeout error message doesn't tell us what exactly failed and some
>> I2C client drivers do not clarify the error either. Adding WARN_ON_ONCE()
>> results in a stacktrace being dumped into KMSG, which is very useful for
>> debugging purposes.
> 
> This is good for debugging, in deed, yet not good in the generic case.
> Timeouts are not an exception on the I2C bus (think of an EEPROM which
> is busy during an erase cycle), so it shouldn't be printed at all.
> 
> This prinout should rather be dropped or at least be dev_dbg.

Oh, well. I'll keep this debugging applied locally then, it's quite
unfortunate when something fails silently :)