[ti:ti-rt-linux-5.10.y 3870/9320] drivers/pci/endpoint/pci-epf-core.c:84:17: warning: Value stored to 'dev' during its initialization is never read [clang-analyzer-deadcode.DeadStores]

From: kernel test robot
Date: Sun Sep 19 2021 - 06:32:05 EST

tree: git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git ti-rt-linux-5.10.y
head: 716065a9435e7c06986b8497aa853a7b747a9570
commit: 5fe4c2dfaa4e6413f98aedd00c8b2b372e5b0103 [3870/9320] PCI: endpoint: Add support to associate secondary EPC with EPF
:::::: branch date: 2 days ago
:::::: commit date: 6 months ago
config: riscv-randconfig-c006-20210916 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c8b3d7d6d6de37af68b2f379d0e37304f78e115f)
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 riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
git remote add ti git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git
git fetch --no-tags ti ti-rt-linux-5.10.y
git checkout 5fe4c2dfaa4e6413f98aedd00c8b2b372e5b0103
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv clang-analyzer

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


clang-analyzer warnings: (prefixed by >>)

>> drivers/pci/endpoint/pci-epf-core.c:84:17: warning: Value stored to 'dev' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
struct device *dev = epf->epc->dev.parent;
^~~ ~~~~~~~~~~~~~~~~~~~~


vim +/dev +84 drivers/pci/endpoint/pci-epf-core.c

5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 71
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 72 /**
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 73 * pci_epf_free_space() - free the allocated PCI EPF register space
9b41d19aff4090 Krzysztof Kozlowski 2020-07-29 74 * @epf: the EPF device from whom to free the memory
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 75 * @addr: the virtual address of the PCI EPF register space
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 76 * @bar: the BAR number corresponding to the register space
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 77 * @type: Identifies if the allocated space is for primary EPC or secondary EPC
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 78 *
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 79 * Invoke to free the allocated PCI EPF register space.
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 80 */
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 81 void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 82 enum pci_epc_interface_type type)
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 83 {
b330104fa76df3 Kishon Vijay Abraham I 2018-01-11 @84 struct device *dev = epf->epc->dev.parent;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 85 struct pci_epf_bar *epf_bar;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 86 struct pci_epc *epc;
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 87
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 88 if (!addr)
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 89 return;
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 90
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 91 if (type == PRIMARY_INTERFACE) {
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 92 epc = epf->epc;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 93 epf_bar = epf->bar;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 94 } else {
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 95 epc = epf->sec_epc;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 96 epf_bar = epf->sec_epc_bar;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 97 }
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 98
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 99 dev = epc->dev.parent;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 100 dma_free_coherent(dev, epf_bar[bar].size, addr,
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 101 epf_bar[bar].phys_addr);
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 102
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 103 epf_bar[bar].phys_addr = 0;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 104 epf_bar[bar].addr = NULL;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 105 epf_bar[bar].size = 0;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 106 epf_bar[bar].barno = 0;
5fe4c2dfaa4e64 Kishon Vijay Abraham I 2021-03-19 107 epf_bar[bar].flags = 0;
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 108 }
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 109 EXPORT_SYMBOL_GPL(pci_epf_free_space);
5e8cb4033807e3 Kishon Vijay Abraham I 2017-04-10 110

:::::: The code at line 84 was first introduced by commit
:::::: b330104fa76df3eae6e199a23791fed5d35f06b4 PCI: endpoint: Use EPC's device in dma_alloc_coherent()/dma_free_coherent()

:::::: TO: Kishon Vijay Abraham I <kishon@xxxxxx>
:::::: CC: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>

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

Attachment: .config.gz
Description: application/gzip