Hi Chris,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on drm-intel/for-linux-next]
[also build test WARNING on drm-tip/drm-tip]
[cannot apply to v5.8-rc3 next-20200701]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Chris-Wilson/drm-i915-gt-Harden-the-heartbeat-against-a-stuck-driver/20200701-164638
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: x86_64-allyesconfig (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project c8f1d442d0858f66fd4128fde6f67eb5202fa2b1)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/i915/gt/intel_ring_scheduler.c:44:42: warning: implicit conversion from 'u64' (aka 'unsigned long long') to 'int' changes value from 18446744073709551615 to -1 [-Wconstant-conversion]
           return rb ? to_priolist(rb)->deadline : I915_DEADLINE_NEVER;
           ~~~~~~                                  ^~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/i915/i915_scheduler_types.h:87:29: note: expanded from macro 'I915_DEADLINE_NEVER'
   #define I915_DEADLINE_NEVER U64_MAX
                               ^~~~~~~
   include/linux/limits.h:22:19: note: expanded from macro 'U64_MAX'
   #define U64_MAX         ((u64)~0ULL)
                            ^~~~~~~~~~
   drivers/gpu/drm/i915/gt/intel_ring_scheduler.c:42:19: warning: unused function 'queue_deadline' [-Wunused-function]
   static inline int queue_deadline(struct rb_node *rb)
                     ^
>> drivers/gpu/drm/i915/gt/intel_ring_scheduler.c:47:20: warning: function 'reset_in_progress' is not needed and will not be emitted [-Wunneeded-internal-declaration]
   static inline bool reset_in_progress(const struct intel_engine_execlists *el)
                      ^
   drivers/gpu/drm/i915/gt/intel_ring_scheduler.c:115:20: warning: unused function 'ring_map_dw' [-Wunused-function]
   static inline u32 *ring_map_dw(struct intel_ring *ring, u32 len)
                      ^
   4 warnings generated.

vim +44 drivers/gpu/drm/i915/gt/intel_ring_scheduler.c

    41	
  > 42	static inline int queue_deadline(struct rb_node *rb)
    43	{
  > 44		return rb ? to_priolist(rb)->deadline : I915_DEADLINE_NEVER;
    45	}
    46	
  > 47	static inline bool reset_in_progress(const struct intel_engine_execlists *el)
    48	{
    49		return unlikely(!__tasklet_is_enabled(&el->tasklet));
    50	}
    51	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org