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    clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940 · 5babc397
    Tony Lindgren authored
    commit 25de4ce5ed02994aea8bc111d133308f6fd62566 upstream.
    
    There is a timer wrap issue on dra7 for the ARM architected timer.
    In a typical clock configuration the timer fails to wrap after 388 days.
    
    To work around the issue, we need to use timer-ti-dm percpu timers instead.
    
    Let's configure dmtimer3 and 4 as percpu timers by default, and warn about
    the issue if the dtb is not configured properly.
    
    For more information, please see the errata for "AM572x Sitara Processors
    Silicon Revisions 1.1, 2.0":
    
    https://www.ti.com/lit/er/sprz429m/sprz429m.pdf
    
    
    
    The concept is based on earlier reference patches done by Tero Kristo and
    Keerthy.
    
    Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
    Cc: Keerthy <j-keerthy@ti.com>
    Cc: Tero Kristo <kristo@kernel.org>
    [tony@atomide.com: backported to 5.4.y]
    Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    5babc397