Re: [PATCH v3 3/3] PCI: dw-rockchip: Add pcie_ltssm_state_transition trace support

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

Hi Shawn,

kernel test robot noticed the following build warnings:

[auto build test WARNING on pci/next]
[also build test WARNING on next-20260109]
[cannot apply to pci/for-linus trace/for-next mani-mhi/mhi-next linus/master v6.19-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/Shawn-Lin/PCI-trace-Add-PCI-controller-LTSSM-transition-tracepoint/20260112-100141
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/1768180800-63364-4-git-send-email-shawn.lin%40rock-chips.com
patch subject: [PATCH v3 3/3] PCI: dw-rockchip: Add pcie_ltssm_state_transition trace support
config: arm64-randconfig-002-20260112 (https://download.01.org/0day-ci/archive/20260112/202601121734.epct0ieX-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260112/202601121734.epct0ieX-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/202601121734.epct0ieX-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/pci/controller/dwc/pcie-dw-rockchip.c: In function 'rockchip_pcie_ltssm_trace_work':
   drivers/pci/controller/dwc/pcie-dw-rockchip.c:264:6: error: implicit declaration of function 'dw_pcie_ltssm_status_string'; did you mean 'dw_pcie_start_link'? [-Werror=implicit-function-declaration]
         dw_pcie_ltssm_status_string(state),
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~
         dw_pcie_start_link
>> drivers/pci/controller/dwc/pcie-dw-rockchip.c:264:6: warning: passing argument 2 of 'trace_pcie_ltssm_state_transition' makes pointer from integer without a cast [-Wint-conversion]
         dw_pcie_ltssm_status_string(state),
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from include/trace/events/pci_controller.h:9,
                    from drivers/pci/controller/dwc/pcie-dw-rockchip.c:26:
   include/trace/events/pci_controller.h:20:45: note: expected 'const char *' but argument is of type 'int'
     TP_PROTO(const char *dev_name, const char *state, u32 rate),
                                    ~~~~~~~~~~~~^~~~~
   include/linux/tracepoint.h:288:34: note: in definition of macro '__DECLARE_TRACE'
     static inline void trace_##name(proto)    \
                                     ^~~~~
   include/linux/tracepoint.h:494:24: note: in expansion of macro 'PARAMS'
     __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),  \
                           ^~~~~~
   include/linux/tracepoint.h:632:2: note: in expansion of macro 'DECLARE_TRACE_EVENT'
     DECLARE_TRACE_EVENT(name, PARAMS(proto), PARAMS(args))
     ^~~~~~~~~~~~~~~~~~~
   include/linux/tracepoint.h:632:28: note: in expansion of macro 'PARAMS'
     DECLARE_TRACE_EVENT(name, PARAMS(proto), PARAMS(args))
                               ^~~~~~
   include/trace/events/pci_controller.h:19:1: note: in expansion of macro 'TRACE_EVENT'
    TRACE_EVENT(pcie_ltssm_state_transition,
    ^~~~~~~~~~~
   include/trace/events/pci_controller.h:20:2: note: in expansion of macro 'TP_PROTO'
     TP_PROTO(const char *dev_name, const char *state, u32 rate),
     ^~~~~~~~
   cc1: some warnings being treated as errors


vim +/trace_pcie_ltssm_state_transition +264 drivers/pci/controller/dwc/pcie-dw-rockchip.c

   225	
   226	#ifdef CONFIG_TRACING
   227	static void rockchip_pcie_ltssm_trace_work(struct work_struct *work)
   228	{
   229		struct rockchip_pcie *rockchip = container_of(work, struct rockchip_pcie,
   230							trace_work.work);
   231		struct dw_pcie *pci = &rockchip->pci;
   232		enum dw_pcie_ltssm state;
   233		u32 i, l1ss, prev_val = DW_PCIE_LTSSM_UNKNOWN, rate, val;
   234	
   235		for (i = 0; i < PCIE_DBG_LTSSM_HISTORY_CNT; i++) {
   236			val = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_DBG_FIFO_STATUS);
   237			rate = FIELD_GET(PCIE_DBG_FIFO_RATE_MASK, val);
   238			l1ss = FIELD_GET(PCIE_DBG_FIFO_L1SUB_MASK, val);
   239			val = FIELD_GET(PCIE_LTSSM_STATUS_MASK, val);
   240	
   241			/*
   242			 * Hardware Mechanism: The ring FIFO employs two tracking counters:
   243			 * - 'last-read-point': maintains the user's last read position
   244			 * - 'last-valid-point': tracks the hardware's last state update
   245			 *
   246			 * Software Handling: When two consecutive LTSSM states are identical,
   247			 * it indicates invalid subsequent data in the FIFO. In this case, we
   248			 * skip the remaining entries. The dual-counter design ensures that on
   249			 * the next state transition, reading can resume from the last user
   250			 * position.
   251			 */
   252			if ((i > 0 && val == prev_val) || val > DW_PCIE_LTSSM_RCVRY_EQ3)
   253				break;
   254	
   255			state = prev_val = val;
   256			if (val == DW_PCIE_LTSSM_L1_IDLE) {
   257				if (l1ss == 2)
   258					state = DW_PCIE_LTSSM_L1_2;
   259				else if (l1ss == 1)
   260					state = DW_PCIE_LTSSM_L1_1;
   261			}
   262	
   263			trace_pcie_ltssm_state_transition(dev_name(pci->dev),
 > 264						dw_pcie_ltssm_status_string(state),
   265						((rate + 1) > pci->max_link_speed) ?
   266						PCI_SPEED_UNKNOWN : PCIE_SPEED_2_5GT + rate);
   267		}
   268	
   269		schedule_delayed_work(&rockchip->trace_work, msecs_to_jiffies(5000));
   270	}
   271	

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