drm/i915: Check for fused or unused pipes

We may have fused or unused pipes in our system. Let's check that the pipe
in question is within limits of accessible pipes. In case, that we are not
able to access the pipe, we return early with a warning.

v2: Rephrasing of the commit message (Jani)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103206
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jaswinder Singh Rajput <jaswinder@perfectintelligent.com>
Suggested-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1513584243-12607-1-git-send-email-mika.kahola@intel.com

diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index f1502a0..522d54f 100644 (file)
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -779,7 +779,7 @@ static struct intel_encoder *get_saved_enc(struct drm_i915_private *dev_priv,
 {
        struct intel_encoder *encoder;
 
-       if (WARN_ON(pipe >= INTEL_INFO(dev_priv)->num_pipes))
+       if (WARN_ON(pipe >= ARRAY_SIZE(dev_priv->av_enc_map)))
                return NULL;
 
        /* MST */