drm/i915: Free write_buf that we allocated with kzalloc.

We use kzalloc to allocate the write_buf that we use for
i2c transfer on hdcp write. But it seems that we are forgetting
to free the memory that is not needed after i2c transfer is
completed.

Reported-by: Brian J Wood <brian.j.wood@intel.com>
Fixes: 2320175feb74 ("drm/i915: Implement HDCP for HDMI")
Cc: Ramalingam C <ramalingam.c@intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: <stable@vger.kernel.org> # v4.17+
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180823205136.31310-1-rodrigo.vivi@intel.com

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 8363fbd18ee870c1a3f54466b5d42ac1f21cad13..a1799b5c12bbc45c4b36eccbfa6037e3cefdc30e 100644 (file)
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -943,8 +943,12 @@ static int intel_hdmi_hdcp_write(struct intel_digital_port *intel_dig_port,
 
        ret = i2c_transfer(adapter, &msg, 1);
        if (ret == 1)
-               return 0;
-       return ret >= 0 ? -EIO : ret;
+               ret = 0;
+       else if (ret >= 0)
+               ret = -EIO;
+
+       kfree(write_buf);
+       return ret;
 }
 
 static