Re: [PATCH V1 2/3] drivers: misc: dcc: Add driver support for Data Capture and Compare unit(DCC)

kernel test robot
2023-04-18T05:19:29Z

Hi Souradeep,

kernel test robot noticed the following build warnings:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus linus/master v6.3-rc7 next-20230417]
[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/Souradeep-Chowdhury/dt-bindings-misc-qcom-dcc-Add-the-dtschema/20230414-220304
patch link: https://lore.kernel.org/r/b1a9cbbcfefe133cc9047a71a2acdaa74239df29.1681480351.git.quic_schowdhu%40quicinc.com
patch subject: [PATCH V1 2/3] drivers: misc: dcc: Add driver support for Data Capture and Compare unit(DCC)
config: arm64-allmodconfig (https://download.01.org/0day-ci/archive/20230418/202304181327.0grVYsHS-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project 9638da200e00bd069e6dd63604e14cbafede9324)
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 arm64 cross compiling tool for clang build
# apt-get install binutils-aarch64-linux-gnu
# https://github.com/intel-lab-lkp/linux/commit/f3f73f6008e1ebca6fba848e260b1f938d91be95
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Souradeep-Chowdhury/dt-bindings-misc-qcom-dcc-Add-the-dtschema/20230414-220304
git checkout f3f73f6008e1ebca6fba848e260b1f938d91be95
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/misc/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304181327.0grVYsHS-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/misc/dcc.c:217:14: warning: variable 'ret' is used uninitialized whenever 'for' loop exits because its condition is false [-Wsometimes-uninitialized]
for (i = 0; i < drvdata->nr_link_list; i++) {
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/misc/dcc.c:238:9: note: uninitialized use occurs here
return ret;
^~~
drivers/misc/dcc.c:217:14: note: remove the condition if it is always true
for (i = 0; i < drvdata->nr_link_list; i++) {
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/misc/dcc.c:190:9: note: initialize the variable 'ret' to silence this warning
int ret;
^
= 0
1 warning generated.

vim +217 drivers/misc/dcc.c

186
187 static int dcc_sw_trigger(struct dcc_drvdata *drvdata)
188 {
189 void __iomem *addr;
190 int ret;
191 int i;
192 u32 status;
193 u32 ll_cfg;
194 u32 tmp_ll_cfg;
195 u32 val;
196
197 mutex_lock(&drvdata->mutex);
198
199 for (i = 0; i < drvdata->nr_link_list; i++) {
200 if (!test_bit(i, drvdata->enable_bitmap))
201 continue;
202 ll_cfg = dcc_list_readl(drvdata, i, DCC_LL_CFG);
203 tmp_ll_cfg = ll_cfg & ~DCC_TRIGGER_MASK;
204 dcc_list_writel(drvdata, tmp_ll_cfg, i, DCC_LL_CFG);
205 dcc_list_writel(drvdata, 1, i, DCC_LL_SW_TRIGGER);
206 dcc_list_writel(drvdata, ll_cfg, i, DCC_LL_CFG);
207 }
208
209 addr = drvdata->base + DCC_STATUS(drvdata->mem_map_ver);
210 if (readl_poll_timeout(addr, val, !FIELD_GET(DCC_STATUS_MASK, val),
211 1, STATUS_READY_TIMEOUT)) {
212 dev_err(drvdata->dev, "DCC is busy after receiving sw trigger\n");
213 ret = -EBUSY;
214 goto out_unlock;
215 }
216
> 217 for (i = 0; i < drvdata->nr_link_list; i++) {
218 if (!test_bit(i, drvdata->enable_bitmap))
219 continue;
220
221 status = dcc_list_readl(drvdata, i, DCC_LL_BUS_ACCESS_STATUS);
222 if (!status)
223 continue;
224
225 dev_err(drvdata->dev, "Read access error for list %d err: 0x%x\n",
226 i, status);
227 ll_cfg = dcc_list_readl(drvdata, i, DCC_LL_CFG);
228 tmp_ll_cfg = ll_cfg & ~DCC_TRIGGER_MASK;
229 dcc_list_writel(drvdata, tmp_ll_cfg, i, DCC_LL_CFG);
230 dcc_list_writel(drvdata, DCC_STATUS_MASK, i, DCC_LL_BUS_ACCESS_STATUS);
231 dcc_list_writel(drvdata, ll_cfg, i, DCC_LL_CFG);
232 ret = -ENODATA;
233 break;
234 }
235
236 out_unlock:
237 mutex_unlock(&drvdata->mutex);
238 return ret;
239 }
240

--
0-DAY CI Kernel Test Service