Re: [Patch] thunderbolt: Add quirk to reset downstream port

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

Hi Sanath,

kernel test robot noticed the following build warnings:

[auto build test WARNING on westeri-thunderbolt/next]
[also build test WARNING on linus/master v6.7-rc2 next-20231121]
[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/Sanath-S/thunderbolt-Add-quirk-to-reset-downstream-port/20231122-014913
base:   https://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt.git next
patch link:    https://lore.kernel.org/r/20231121174701.3922587-1-Sanath.S%40amd.com
patch subject: [Patch] thunderbolt: Add quirk to reset downstream port
config: x86_64-buildonly-randconfig-003-20231122 (https://download.01.org/0day-ci/archive/20231122/202311220931.2IqiKNXr-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231122/202311220931.2IqiKNXr-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/202311220931.2IqiKNXr-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/thunderbolt/switch.c:1556:2: warning: variable 'ret' is used uninitialized whenever 'for' loop exits because its condition is false [-Wsometimes-uninitialized]
           tb_switch_for_each_port(sw, port) {
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/thunderbolt/tb.h:821:7: note: expanded from macro 'tb_switch_for_each_port'
                (p) <= &(sw)->ports[(sw)->config.max_port_number]; (p)++)
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/thunderbolt/switch.c:1564:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   drivers/thunderbolt/switch.c:1556:2: note: remove the condition if it is always true
           tb_switch_for_each_port(sw, port) {
           ^
   drivers/thunderbolt/tb.h:821:7: note: expanded from macro 'tb_switch_for_each_port'
                (p) <= &(sw)->ports[(sw)->config.max_port_number]; (p)++)
                ^
   drivers/thunderbolt/switch.c:1554:9: note: initialize the variable 'ret' to silence this warning
           int ret;
                  ^
                   = 0
   1 warning generated.


vim +1556 drivers/thunderbolt/switch.c

  1549	
  1550	static int tb_switch_reset_downstream_port(struct tb_switch *sw)
  1551	{
  1552		struct tb_port *port;
  1553		uint32_t val = 0;
  1554		int ret;
  1555	
> 1556		tb_switch_for_each_port(sw, port) {
  1557			if (port->config.type == TB_TYPE_PORT) {
  1558				val = val | PORT_CS_19_DPR;
  1559				ret = tb_port_write(port, &val, TB_CFG_PORT,
  1560						port->cap_usb4 + PORT_CS_19, 1);
  1561				break;
  1562			}
  1563		}
  1564		return ret;
  1565	}
  1566	

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