• Chris Wilson's avatar
    drm/i915: Provide a timeout to i915_gem_wait_for_idle() · ec625fb9
    Chris Wilson authored
    Usually we have no idea about the upper bound we need to wait to catch
    up with userspace when idling the device, but in a few situations we
    know the system was idle beforehand and can provide a short timeout in
    order to very quickly catch a failure, long before hangcheck kicks in.
    
    In the following patches, we will use the timeout to curtain two overly
    long waits, where we know we can expect the GPU to complete within a
    reasonable time or declare it broken.
    
    In particular, with a broken GPU we expect it to fail during the initial
    GPU setup where do a couple of context switches to record the defaults.
    This is a task that takes a few milliseconds even on the slowest of
    devices, but we may have to wait 60s for hangcheck to give in and
    declare the machine inoperable. In this a case where any gpu hang is
    unacceptable, both from a timeliness and practical standpoint.
    
    The other improvement is that in selftests, we do not need to arm an
    independent timer to inject a wedge, as we can just limit the timeout on
    the wait directly.
    
    v2: Include the timeout parameter in the trace.
    Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
    Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
    Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
    Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
    Reviewed-by: default avatarMika Kuoppala <mika.kuoppala@linux.intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20180709122044.7028-1-chris@chris-wilson.co.uk
    ec625fb9
i915_debugfs.c 136 KB