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[ Upstream commit d1baf7a3a3177d46a7149858beddb88a9eca7a54 ] Make sure that the support of PEC is determined before the read of other registers. Otherwise the validation of PEC can trigger an error on the read of STATUS_BYTE or STATUS_WORD registers. The problematic scenario is the following. A device with enabled PEC support is up and running and a kernel driver is loaded. Then the driver is unloaded (or device unbound), the HW device is reconfigured externally (e.g. by i2cset) to advertise itself as not supporting PEC. Without the move of the code, at the second load of the driver (or bind) the STATUS_BYTE or STATUS_WORD register is always read with PEC enabled, which is likely to cause a read error resulting with fail of a driver load (or bind). Signed-off-by: Adam Wujek <dev_public@wujek.eu> Link: https://lore.kernel.org/r/20220519233334.438621-1-dev_public@wujek.eu Fixes: 75d2b2b06bd84 ("hwmon: (pmbus) disable PEC if not enabled") Fixes: 4e5418f787ec5 ("hwmon: (pmbus_core) Check adapter PEC support") [groeck: Added Fixes: tags, dropped continuation line] Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.