drm/i915: Hold rpm wakeref for modifying the global seqno

To modify the global seqno may require rewriting a few registers, which
requires us to hold the rpm wakeref. We must therefore take it around
the call to i915_gem_set_global_seqno() in debugfs, on behalf of the
user.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180102151235.3949-15-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index d81cb25..2bb6307 100644 (file)
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -988,7 +988,10 @@ i915_next_seqno_set(void *data, u64 val)
        if (ret)
                return ret;
 
+       intel_runtime_pm_get(dev_priv);
        ret = i915_gem_set_global_seqno(dev, val);
+       intel_runtime_pm_put(dev_priv);
+
        mutex_unlock(&dev->struct_mutex);
 
        return ret;