Hi Anindya, 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/Anindya-Sundar-Gayen/i2c-algo-bit-Added-the-bus-lock-during-a-i2c-transaction/20250225-201732 base: https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git i2c/i2c-host patch link: https://lore.kernel.org/r/20250225113314.12353-1-anindya.sg%40samsung.com patch subject: [PATCH] i2c-algo-bit: Added the bus lock during a i2c transaction config: powerpc-randconfig-r071-20250228 (https://download.01.org/0day-ci/archive/20250228/202502281946.tIwDrE9k-lkp@xxxxxxxxx/config) compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project 204dcafec0ecf0db81d420d2de57b02ada6b09ec) 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@xxxxxxxxx> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202502281946.tIwDrE9k-lkp@xxxxxxxxx/ smatch warnings: drivers/i2c/algos/i2c-algo-bit.c:385 sendbytes() warn: inconsistent returns 'global &i2c_bus_lock'. vim +385 drivers/i2c/algos/i2c-algo-bit.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 344 static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) ^1da177e4c3f41 Linus Torvalds 2005-04-16 345 { 494dbb64dc5b36 Jean Delvare 2007-05-01 346 const unsigned char *temp = msg->buf; ^1da177e4c3f41 Linus Torvalds 2005-04-16 347 int count = msg->len; ^1da177e4c3f41 Linus Torvalds 2005-04-16 348 unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; ^1da177e4c3f41 Linus Torvalds 2005-04-16 349 int retval; ^1da177e4c3f41 Linus Torvalds 2005-04-16 350 int wrcount = 0; ^1da177e4c3f41 Linus Torvalds 2005-04-16 351 8eb6c9a270e167 Anindya Sundar Gayen 2025-02-25 352 /* Aquire the lock before accessing the I2C bus */ 8eb6c9a270e167 Anindya Sundar Gayen 2025-02-25 353 mutex_lock(&i2c_bus_lock); ^1da177e4c3f41 Linus Torvalds 2005-04-16 354 while (count > 0) { 494dbb64dc5b36 Jean Delvare 2007-05-01 355 retval = i2c_outb(i2c_adap, *temp); cf978ab2846d86 David Brownell 2008-01-27 356 cf978ab2846d86 David Brownell 2008-01-27 357 /* OK/ACK; or ignored NAK */ cf978ab2846d86 David Brownell 2008-01-27 358 if ((retval > 0) || (nak_ok && (retval == 0))) { ^1da177e4c3f41 Linus Torvalds 2005-04-16 359 count--; ^1da177e4c3f41 Linus Torvalds 2005-04-16 360 temp++; ^1da177e4c3f41 Linus Torvalds 2005-04-16 361 wrcount++; bf3e2d1d9b8605 David Brownell 2008-01-27 362 bf3e2d1d9b8605 David Brownell 2008-01-27 363 /* A slave NAKing the master means the slave didn't like bf3e2d1d9b8605 David Brownell 2008-01-27 364 * something about the data it saw. For example, maybe bf3e2d1d9b8605 David Brownell 2008-01-27 365 * the SMBus PEC was wrong. bf3e2d1d9b8605 David Brownell 2008-01-27 366 */ bf3e2d1d9b8605 David Brownell 2008-01-27 367 } else if (retval == 0) { bf3e2d1d9b8605 David Brownell 2008-01-27 368 dev_err(&i2c_adap->dev, "sendbytes: NAK bailout.\n"); bf3e2d1d9b8605 David Brownell 2008-01-27 369 return -EIO; mutex_unlock(&i2c_bus_lock); bf3e2d1d9b8605 David Brownell 2008-01-27 370 bf3e2d1d9b8605 David Brownell 2008-01-27 371 /* Timeout; or (someday) lost arbitration bf3e2d1d9b8605 David Brownell 2008-01-27 372 * bf3e2d1d9b8605 David Brownell 2008-01-27 373 * FIXME Lost ARB implies retrying the transaction from bf3e2d1d9b8605 David Brownell 2008-01-27 374 * the first message, after the "winning" master issues bf3e2d1d9b8605 David Brownell 2008-01-27 375 * its STOP. As a rule, upper layer code has no reason bf3e2d1d9b8605 David Brownell 2008-01-27 376 * to know or care about this ... it is *NOT* an error. bf3e2d1d9b8605 David Brownell 2008-01-27 377 */ bf3e2d1d9b8605 David Brownell 2008-01-27 378 } else { bf3e2d1d9b8605 David Brownell 2008-01-27 379 dev_err(&i2c_adap->dev, "sendbytes: error %d\n", bf3e2d1d9b8605 David Brownell 2008-01-27 380 retval); bf3e2d1d9b8605 David Brownell 2008-01-27 381 return retval; And here too. ^1da177e4c3f41 Linus Torvalds 2005-04-16 382 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 383 } 8eb6c9a270e167 Anindya Sundar Gayen 2025-02-25 384 mutex_unlock(&i2c_bus_lock); ^1da177e4c3f41 Linus Torvalds 2005-04-16 @385 return wrcount; ^1da177e4c3f41 Linus Torvalds 2005-04-16 386 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
