• Martin Kaiser's avatar
    watchdog: imx2_wdt: restore previous timeout after suspend+resume · 0be26725
    Martin Kaiser authored
    When the watchdog device is suspended, its timeout is set to the maximum
    value. During resume, the previously set timeout should be restored.
    This does not work at the moment.
    
    The suspend function calls
    
    imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
    
    and resume reverts this by calling
    
    imx2_wdt_set_timeout(wdog, wdog->timeout);
    
    However, imx2_wdt_set_timeout() updates wdog->timeout. Therefore,
    wdog->timeout is set to IMX2_WDT_MAX_TIME when we enter the resume
    function.
    
    Fix this by adding a new function __imx2_wdt_set_timeout() which
    only updates the hardware settings. imx2_wdt_set_timeout() now calls
    __imx2_wdt_set_timeout() and then saves the new timeout to
    wdog->timeout.
    
    During suspend, we call __imx2_wdt_set_timeout() directly so that
    wdog->timeout won't be updated and we can restore the previous value
    during resume. This approach makes wdog->timeout different from the
    actual setting in the hardware which is usually not a good thing.
    However, the two differ only while we're suspended and no kernel code is
    running, so it should be ok in this case.
    Signed-off-by: default avatarMartin Kaiser <martin@kaiser.cx>
    Cc: stable@vger.kernel.org
    Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
    Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
    Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
    0be26725
imx2_wdt.c 12.1 KB