On 9/13/2023 3:18 PM, Dan Carpenter wrote:
> Hi Qiang,
>
> kernel test robot noticed the following build warnings:
>
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Qiang-Yu/bus-mhi-host-Add-spinlock-to-protect-WP-access-when-queueing-TREs/20230912-072349
> base: linus/master
> patch link: https://lore.kernel.org/r/1694426069-74140-2-git-send-email-quic_qianyu%40quicinc.com
> patch subject: [PATCH 1/2] bus: mhi: host: Add spinlock to protect WP access when queueing TREs
> config: i386-randconfig-141-20230913 (https://download.01.org/0day-ci/archive/20230913/[email protected]/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce: (https://download.01.org/0day-ci/archive/20230913/[email protected]/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 <[email protected]>
> | Reported-by: Dan Carpenter <[email protected]>
> | Closes: https://lore.kernel.org/r/[email protected]/
>
> smatch warnings:
> drivers/bus/mhi/host/main.c:1249 mhi_gen_tre() warn: inconsistent returns '&mhi_chan->lock'.
>
> vim +1249 drivers/bus/mhi/host/main.c
Thanks for reporting this error. Added write_unlock_bh(&mhi_chan->lock)
before return because of error process in v2 patch.
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1200 int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1201 struct mhi_buf_info *info, enum mhi_flags flags)
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1202 {
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1203 struct mhi_ring *buf_ring, *tre_ring;
> 84f5f31f110e5e drivers/bus/mhi/host/main.c Manivannan Sadhasivam 2022-03-01 1204 struct mhi_ring_element *mhi_tre;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1205 struct mhi_buf_info *buf_info;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1206 int eot, eob, chain, bei;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1207 int ret;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1208
> c8a037317010d5 drivers/bus/mhi/host/main.c Bhaumik Bhatt 2023-09-11 1209 /* Protect accesses for reading and incrementing WP */
> c8a037317010d5 drivers/bus/mhi/host/main.c Bhaumik Bhatt 2023-09-11 1210 write_lock_bh(&mhi_chan->lock);
> c8a037317010d5 drivers/bus/mhi/host/main.c Bhaumik Bhatt 2023-09-11 1211
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1212 buf_ring = &mhi_chan->buf_ring;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1213 tre_ring = &mhi_chan->tre_ring;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1214
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1215 buf_info = buf_ring->wp;
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1216 WARN_ON(buf_info->used);
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1217 buf_info->pre_mapped = info->pre_mapped;
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1218 if (info->pre_mapped)
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1219 buf_info->p_addr = info->p_addr;
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1220 else
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1221 buf_info->v_addr = info->v_addr;
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1222 buf_info->cb_buf = info->cb_buf;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1223 buf_info->wp = tre_ring->wp;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1224 buf_info->dir = mhi_chan->dir;
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1225 buf_info->len = info->len;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1226
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1227 if (!info->pre_mapped) {
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1228 ret = mhi_cntrl->map_single(mhi_cntrl, buf_info);
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1229 if (ret)
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1230 return ret;
>
> write_unlock_bh(&mhi_chan->lock);
>
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1231 }
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1232
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1233 eob = !!(flags & MHI_EOB);
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1234 eot = !!(flags & MHI_EOT);
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1235 chain = !!(flags & MHI_CHAIN);
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1236 bei = !!(mhi_chan->intmod);
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1237
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1238 mhi_tre = tre_ring->wp;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1239 mhi_tre->ptr = MHI_TRE_DATA_PTR(buf_info->p_addr);
> cd116318803f5e drivers/bus/mhi/core/main.c Hemant Kumar 2020-05-21 1240 mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(info->len);
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1241 mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(bei, eot, eob, chain);
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1242
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1243 /* increment WP */
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1244 mhi_add_ring_element(mhi_cntrl, tre_ring);
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1245 mhi_add_ring_element(mhi_cntrl, buf_ring);
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1246
> c8a037317010d5 drivers/bus/mhi/host/main.c Bhaumik Bhatt 2023-09-11 1247 write_unlock_bh(&mhi_chan->lock);
> c8a037317010d5 drivers/bus/mhi/host/main.c Bhaumik Bhatt 2023-09-11 1248
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 @1249 return 0;
> 189ff97cca53e3 drivers/bus/mhi/core/main.c Manivannan Sadhasivam 2020-02-20 1250 }
>