Re: [PATCH v2 5/6] drm/i915/psr: Enable ALPM for eDP Panel replay

[kernel test robot <lkp@intel.com>]

Hi Jouni,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-intel/for-linux-next]
[also build test WARNING on drm-tip/drm-tip drm/drm-next next-20240221]
[cannot apply to drm-intel/for-linux-next-fixes linus/master v6.8-rc5]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Jouni-H-gander/drm-display-Add-missing-aux-less-alpm-wake-related-bits/20240220-201356
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
patch link:    https://lore.kernel.org/r/20240220121045.2156004-6-jouni.hogander%40intel.com
patch subject: [PATCH v2 5/6] drm/i915/psr: Enable ALPM for eDP Panel replay
config: riscv-allmodconfig (https://download.01.org/0day-ci/archive/20240222/202402220225.2eViN531-lkp@intel.com/config)
compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project 36adfec155de366d722f2bac8ff9162289dcf06c)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240222/202402220225.2eViN531-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202402220225.2eViN531-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/i915/display/intel_psr.c:1705:3: warning: variable 'alpm_ctl' is uninitialized when used here [-Wuninitialized]
    1705 |                 alpm_ctl |= ALPM_CTL_ALPM_ENABLE |
         |                 ^~~~~~~~
   drivers/gpu/drm/i915/display/intel_psr.c:1699:14: note: initialize the variable 'alpm_ctl' to silence this warning
    1699 |         u32 alpm_ctl;
         |                     ^
         |                      = 0
   1 warning generated.


vim +/alpm_ctl +1705 drivers/gpu/drm/i915/display/intel_psr.c

  1693	
  1694	static void lnl_alpm_configure(struct intel_dp *intel_dp)
  1695	{
  1696		struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
  1697		enum transcoder cpu_transcoder = intel_dp->psr.transcoder;
  1698		struct intel_psr *psr = &intel_dp->psr;
  1699		u32 alpm_ctl;
  1700	
  1701		if (DISPLAY_VER(dev_priv) < 20)
  1702			return;
  1703	
  1704		if (intel_dp->psr.panel_replay_enabled && intel_dp_is_edp(intel_dp)) {
> 1705			alpm_ctl |= ALPM_CTL_ALPM_ENABLE |
  1706				ALPM_CTL_ALPM_AUX_LESS_ENABLE |
  1707				ALPM_CTL_AUX_LESS_SLEEP_HOLD_TIME_50_SYMBOLS;
  1708	
  1709			intel_de_write(dev_priv, PORT_ALPM_CTL(cpu_transcoder),
  1710				       PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE |
  1711				       PORT_ALPM_CTL_MAX_PHY_SWING_SETUP(15) |
  1712				       PORT_ALPM_CTL_MAX_PHY_SWING_HOLD(0) |
  1713				       PORT_ALPM_CTL_SILENCE_PERIOD(
  1714					       psr->alpm_parameters.silence_period_sym_clocks));
  1715	
  1716			intel_de_write(dev_priv, PORT_ALPM_LFPS_CTL(cpu_transcoder),
  1717				       PORT_ALPM_LFPS_CTL_LFPS_CYCLE_COUNT(10) |
  1718				       PORT_ALPM_LFPS_CTL_LFPS_HALF_CYCLE_DURATION(
  1719					       psr->alpm_parameters.lfps_half_cycle_num_of_syms) |
  1720				       PORT_ALPM_LFPS_CTL_FIRST_LFPS_HALF_CYCLE_DURATION(
  1721					       psr->alpm_parameters.lfps_half_cycle_num_of_syms) |
  1722				       PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION(
  1723					       psr->alpm_parameters.lfps_half_cycle_num_of_syms));
  1724		} else {
  1725			alpm_ctl = ALPM_CTL_EXTENDED_FAST_WAKE_ENABLE |
  1726				ALPM_CTL_EXTENDED_FAST_WAKE_TIME(psr->alpm_parameters.fast_wake_lines);
  1727		}
  1728	
  1729		alpm_ctl |= ALPM_CTL_ALPM_ENTRY_CHECK(psr->alpm_parameters.check_entry_lines);
  1730	
  1731		intel_de_write(dev_priv, ALPM_CTL(cpu_transcoder), alpm_ctl);
  1732	}
  1733	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki