commit 920057ad521dc8669e534736c2a12c14ec9fb2d7 upstream. In the regmap conversion in commit 4ef2774511dc ("hwmon: (nct6775) Convert register access to regmap API") I reused the 'reg' variable for all three register reads in the fan speed calculation loop in nct6775_update_device(), but failed to notice that the value from the first one (data->REG_FAN[i]) is actually used in the call to nct6775_select_fan_div() at the end of the loop body. Since that patch the register value passed to nct6775_select_fan_div() has been (conditionally) incorrectly clobbered with the value of a different register than intended, which has in at least some cases resulted in fan speeds being adjusted down to zero. Fix this by using dedicated temporaries for the two intermediate register reads instead of 'reg'. Signed-off-by: Zev Weiss <zev@bewilderbeest.net> Fixes: 4ef2774511dc ("hwmon: (nct6775) Convert register access to regmap API") Reported-by: Thomas Zajic <zlatko@gmx.at> Tested-by: Thomas Zajic <zlatko@gmx.at> Cc: stable@vger.kernel.org # v5.19+ Link: https://lore.kernel.org/r/20230929200822.964-2-zev@bewilderbeest.net Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.
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