tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 5631c5e0eb9035d92ceb20fcd9cdb7779a3f5cc7 commit: 3f649ab728cda8038259d8f14492fe400fbab911 treewide: Remove uninitialized_var() usage date: 3 weeks ago config: i386-randconfig-m021-20200807 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; New smatch warnings: drivers/gpu/drm/i915/intel_uncore.c:2009 __intel_wait_for_register_fw() error: uninitialized symbol 'reg_value'. drivers/gpu/drm/i915/gt/intel_lrc.c:1134 __unwind_incomplete_requests() error: uninitialized symbol 'pl'. Old smatch warnings: drivers/gpu/drm/i915/gt/intel_lrc.c:5668 intel_execlists_create_virtual() warn: assigning (-2) to unsigned variable 've->base.instance' drivers/gpu/drm/i915/gt/intel_lrc.c:5669 intel_execlists_create_virtual() warn: assigning (-2) to unsigned variable 've->base.uabi_instance' vim +/reg_value +2009 drivers/gpu/drm/i915/intel_uncore.c 907b28c56ea4062 Chris Wilson 2013-07-19 1959 1758b90e38f53b9 Chris Wilson 2016-06-30 1960 /** 1d1a9774e404141 Michal Wajdeczko 2017-04-07 1961 * __intel_wait_for_register_fw - wait until register matches expected state d2d551c06f81775 Daniele Ceraolo Spurio 2019-03-25 1962 * @uncore: the struct intel_uncore 1758b90e38f53b9 Chris Wilson 2016-06-30 1963 * @reg: the register to read 1758b90e38f53b9 Chris Wilson 2016-06-30 1964 * @mask: mask to apply to register value 1758b90e38f53b9 Chris Wilson 2016-06-30 1965 * @value: expected value 1d1a9774e404141 Michal Wajdeczko 2017-04-07 1966 * @fast_timeout_us: fast timeout in microsecond for atomic/tight wait 1d1a9774e404141 Michal Wajdeczko 2017-04-07 1967 * @slow_timeout_ms: slow timeout in millisecond 1d1a9774e404141 Michal Wajdeczko 2017-04-07 1968 * @out_value: optional placeholder to hold registry value 1758b90e38f53b9 Chris Wilson 2016-06-30 1969 * 1758b90e38f53b9 Chris Wilson 2016-06-30 1970 * This routine waits until the target register @reg contains the expected 3d466cd67e85fe1 Daniel Vetter 2016-07-15 1971 * @value after applying the @mask, i.e. it waits until :: 3d466cd67e85fe1 Daniel Vetter 2016-07-15 1972 * 3d466cd67e85fe1 Daniel Vetter 2016-07-15 1973 * (I915_READ_FW(reg) & mask) == value 3d466cd67e85fe1 Daniel Vetter 2016-07-15 1974 * 1d1a9774e404141 Michal Wajdeczko 2017-04-07 1975 * Otherwise, the wait will timeout after @slow_timeout_ms milliseconds. 6976e74b5fa1243 Michal Wajdeczko 2017-04-10 1976 * For atomic context @slow_timeout_ms must be zero and @fast_timeout_us 84d84cb7e20d3d2 Chris Wilson 2017-04-11 1977 * must be not larger than 20,0000 microseconds. 1758b90e38f53b9 Chris Wilson 2016-06-30 1978 * 1758b90e38f53b9 Chris Wilson 2016-06-30 1979 * Note that this routine assumes the caller holds forcewake asserted, it is 1758b90e38f53b9 Chris Wilson 2016-06-30 1980 * not suitable for very long waits. See intel_wait_for_register() if you 1758b90e38f53b9 Chris Wilson 2016-06-30 1981 * wish to wait without holding forcewake for the duration (i.e. you expect 1758b90e38f53b9 Chris Wilson 2016-06-30 1982 * the wait to be slow). 1758b90e38f53b9 Chris Wilson 2016-06-30 1983 * e4661f144497f58 Michal Wajdeczko 2019-08-02 1984 * Return: 0 if the register matches the desired condition, or -ETIMEDOUT. 1758b90e38f53b9 Chris Wilson 2016-06-30 1985 */ d2d551c06f81775 Daniele Ceraolo Spurio 2019-03-25 1986 int __intel_wait_for_register_fw(struct intel_uncore *uncore, 1758b90e38f53b9 Chris Wilson 2016-06-30 1987 i915_reg_t reg, 3fc7d86b3268af9 Michal Wajdeczko 2017-04-10 1988 u32 mask, 3fc7d86b3268af9 Michal Wajdeczko 2017-04-10 1989 u32 value, 3fc7d86b3268af9 Michal Wajdeczko 2017-04-10 1990 unsigned int fast_timeout_us, 3fc7d86b3268af9 Michal Wajdeczko 2017-04-10 1991 unsigned int slow_timeout_ms, 1d1a9774e404141 Michal Wajdeczko 2017-04-07 1992 u32 *out_value) 1758b90e38f53b9 Chris Wilson 2016-06-30 1993 { 3f649ab728cda80 Kees Cook 2020-06-03 1994 u32 reg_value; d2d551c06f81775 Daniele Ceraolo Spurio 2019-03-25 1995 #define done (((reg_value = intel_uncore_read_fw(uncore, reg)) & mask) == value) 1d1a9774e404141 Michal Wajdeczko 2017-04-07 1996 int ret; 1d1a9774e404141 Michal Wajdeczko 2017-04-07 1997 6976e74b5fa1243 Michal Wajdeczko 2017-04-10 1998 /* Catch any overuse of this function */ 84d84cb7e20d3d2 Chris Wilson 2017-04-11 1999 might_sleep_if(slow_timeout_ms); 84d84cb7e20d3d2 Chris Wilson 2017-04-11 2000 GEM_BUG_ON(fast_timeout_us > 20000); 6976e74b5fa1243 Michal Wajdeczko 2017-04-10 2001 84d84cb7e20d3d2 Chris Wilson 2017-04-11 2002 ret = -ETIMEDOUT; 84d84cb7e20d3d2 Chris Wilson 2017-04-11 2003 if (fast_timeout_us && fast_timeout_us <= 20000) 1d1a9774e404141 Michal Wajdeczko 2017-04-07 2004 ret = _wait_for_atomic(done, fast_timeout_us, 0); ff26ffa8ee267dc Daniel Vetter 2017-05-10 2005 if (ret && slow_timeout_ms) 1d1a9774e404141 Michal Wajdeczko 2017-04-07 2006 ret = wait_for(done, slow_timeout_ms); 84d84cb7e20d3d2 Chris Wilson 2017-04-11 2007 1d1a9774e404141 Michal Wajdeczko 2017-04-07 2008 if (out_value) 1d1a9774e404141 Michal Wajdeczko 2017-04-07 @2009 *out_value = reg_value; 84d84cb7e20d3d2 Chris Wilson 2017-04-11 2010 1758b90e38f53b9 Chris Wilson 2016-06-30 2011 return ret; 1758b90e38f53b9 Chris Wilson 2016-06-30 2012 #undef done 1758b90e38f53b9 Chris Wilson 2016-06-30 2013 } 1758b90e38f53b9 Chris Wilson 2016-06-30 2014 :::::: The code at line 2009 was first introduced by commit :::::: 1d1a9774e40414148ecebbdb713746bfb6f9a561 drm/i915: Extend intel_wait_for_register_fw() with fast timeout :::::: TO: Michal Wajdeczko <michal.wajdeczko(a)intel.com&gt; :::::: CC: Chris Wilson <chris(a)chris-wilson.co.uk&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org