From: Sven Eckelmann <sven@narfation.org>
To: Chris Packham <chris.packham@alliedtelesis.co.nz>,
Andi Shyti <andi.shyti@kernel.org>, Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Jonas Jelonek <jelonek.jonas@gmail.com>
Cc: linux-i2c@vger.kernel.org, Conor Dooley <conor+dt@kernel.org>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Markus Stockhausen <markus.stockhausen@gmx.de>,
Harshal Gohel <hg@simonwunderlich.de>,
Jonas Jelonek <jelonek.jonas@gmail.com>
Subject: Re: [PATCH v5 06/11] i2c: rtl9300: remove SMBus Quick operation support
Date: Sun, 10 Aug 2025 09:13:07 +0200 [thread overview]
Message-ID: <3644932.iIbC2pHGDl@sven-desktop> (raw)
In-Reply-To: <20250809220713.1038947-7-jelonek.jonas@gmail.com>
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On Sunday, 10 August 2025 00:07:07 CEST Jonas Jelonek wrote:
[...]
> The current implementation of SMBus Quick operation passes a length of
> 0 (which is actually invalid). Before the fix of a bug in a previous
> commit, this led to a read operation of 16 bytes from any register (the
> one of a former transaction or any other value.
>
> Although there are currently no reports of actual issues this caused.
> However, as an example, i2cdetect by default uses Quick Write operation
> to probe the bus and this may already write anything to some register
> of a device, causing unintended behaviour. This could be the cause of a
> recent brick of one of my DAC cables where there was a checksum mismatch
> of the EEPROM after having run 'i2cdetect -l' before.
[...]
Nice find. I've actually observed odd behavior after/during probing and
attributed it only to the other problems (especially the low timeout + missing
check) we found and never did a deep dive to figure out what happened on the
bus during the probe. Possible that this could be related.
Reviewed-by: Sven Eckelmann <sven@narfation.org>
Kind regards,
Sven
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next prev parent reply other threads:[~2025-08-10 7:13 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-09 22:07 [PATCH v5 00/11] i2c: rework and extend RTL9300 I2C driver Jonas Jelonek
2025-08-09 22:07 ` [PATCH v5 01/11] i2c: rtl9300: use regmap fields and API for registers Jonas Jelonek
2025-08-09 22:07 ` [PATCH v5 02/11] i2c: rtl9300: fix channel number bound check Jonas Jelonek
2025-08-09 22:07 ` [PATCH v5 03/11] dt-bindings: i2c: realtek,rtl9301-i2c: fix wording and typos Jonas Jelonek
2025-08-18 15:10 ` Rob Herring (Arm)
2025-08-09 22:07 ` [PATCH v5 04/11] i2c: rtl9300: rename internal sda_pin to sda_num Jonas Jelonek
2025-08-09 22:07 ` [PATCH v5 05/11] i2c: rtl9300: check if xfer length is valid Jonas Jelonek
2025-08-10 5:51 ` Wolfram Sang
2025-08-10 7:01 ` Sven Eckelmann
2025-08-10 9:22 ` Jonas Jelonek
2025-08-09 22:07 ` [PATCH v5 06/11] i2c: rtl9300: remove SMBus Quick operation support Jonas Jelonek
2025-08-10 7:13 ` Sven Eckelmann [this message]
2025-08-10 9:31 ` Jonas Jelonek
2025-08-09 22:07 ` [PATCH v5 07/11] i2c: rtl9300: move setting SCL frequency to config_io Jonas Jelonek
2025-08-10 8:49 ` Markus Elfring
2025-08-10 8:54 ` Sven Eckelmann
2025-08-10 9:10 ` Jonas Jelonek
2025-08-09 22:07 ` [PATCH v5 08/11] i2c: rtl9300: do not set read mode on every transfer Jonas Jelonek
2025-08-09 22:07 ` [PATCH v5 09/11] i2c: rtl9300: separate xfer configuration and execution Jonas Jelonek
2025-08-09 22:07 ` [PATCH v5 10/11] dt-bindings: i2c: realtek,rtl9301-i2c: extend for RTL9310 support Jonas Jelonek
2025-08-18 15:13 ` Rob Herring (Arm)
2025-08-09 22:07 ` [PATCH v5 11/11] i2c: rtl9300: add support for RTL9310 I2C controller Jonas Jelonek
2025-08-10 10:39 ` Sven Eckelmann
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