• Edward A. James's avatar
    hwmon: (pmbus/core) Prevent unintentional setting of page to 0xFF · 6dcf2fb5
    Edward A. James authored
    The pmbus core may call read/write word data functions with a page value
    of -1, intending to perform the operation without setting the page.
    However, the read/write word data functions accept only unsigned 8-bit
    page numbers, and therefore cannot check for negative page number to
    avoid setting the page. This results in setting the page number to 0xFF.
    This may result in errors or undefined behavior of some devices
    (specifically the ir35221, which allows the page to be set to 0xFF,
    but some subsequent operations to read registers may fail).
    
    Switch the pmbus_set_page page parameter to an integer and perform the
    check for negative page there. Make read/write functions consistent in
    accepting an integer page number parameter.
    Signed-off-by: default avatarEdward A. James <eajames@us.ibm.com>
    Fixes: cbcdec62 ("hwmon: (pmbus): Access word data for STATUS_WORD")
    Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
    6dcf2fb5
pmbus.h 12.6 KB