From: Dan Carpenter <dan.carpenter@linaro.org>
To: oe-kbuild@lists.linux.dev,
Marcus Folkesson <marcus.folkesson@gmail.com>,
Wolfram Sang <wsa-dev@sang-engineering.com>,
Peter Rosin <peda@axentia.se>,
Michael Hennerich <michael.hennerich@analog.com>,
Bartosz Golaszewski <brgl@bgdev.pl>,
Andi Shyti <andi.shyti@kernel.org>
Cc: lkp@intel.com, oe-kbuild-all@lists.linux.dev,
linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Marcus Folkesson <marcus.folkesson@gmail.com>
Subject: Re: [PATCH v2 2/5] i2c: mux: add support for per channel bus frequency
Date: Fri, 3 Oct 2025 13:57:11 +0300 [thread overview]
Message-ID: <202510031735.TE7FVj0R-lkp@intel.com> (raw)
In-Reply-To: <20251002-i2c-mux-v2-2-b698564cd956@gmail.com>
Hi Marcus,
kernel test robot noticed the following build warnings:
url: https://github.com/intel-lab-lkp/linux/commits/Marcus-Folkesson/i2c-core-add-callback-to-change-bus-frequency/20251002-224414
base: 22f20375f5b71f30c0d6896583b93b6e4bba7279
patch link: https://lore.kernel.org/r/20251002-i2c-mux-v2-2-b698564cd956%40gmail.com
patch subject: [PATCH v2 2/5] i2c: mux: add support for per channel bus frequency
config: i386-randconfig-141-20251003 (https://download.01.org/0day-ci/archive/20251003/202510031735.TE7FVj0R-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
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>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202510031735.TE7FVj0R-lkp@intel.com/
smatch warnings:
drivers/i2c/i2c-mux.c:506 i2c_mux_add_adapter() error: uninitialized symbol 'ret'.
vim +/ret +506 drivers/i2c/i2c-mux.c
a7ab72390b7706 Peter Rosin 2016-04-20 336 int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
fec1982d70721c Heiner Kallweit 2024-04-18 337 u32 force_nr, u32 chan_id)
a7ab72390b7706 Peter Rosin 2016-04-20 338 {
a7ab72390b7706 Peter Rosin 2016-04-20 339 struct i2c_adapter *parent = muxc->parent;
0826374bff5741 Michael Lawnick 2010-08-11 340 struct i2c_mux_priv *priv;
c9449affad2ae0 Gerlando Falauto 2014-11-13 341 char symlink_name[20];
0826374bff5741 Michael Lawnick 2010-08-11 342 int ret;
0826374bff5741 Michael Lawnick 2010-08-11 343
a7ab72390b7706 Peter Rosin 2016-04-20 344 if (muxc->num_adapters >= muxc->max_adapters) {
a7ab72390b7706 Peter Rosin 2016-04-20 345 dev_err(muxc->dev, "No room for more i2c-mux adapters\n");
a7ab72390b7706 Peter Rosin 2016-04-20 346 return -EINVAL;
a7ab72390b7706 Peter Rosin 2016-04-20 347 }
a7ab72390b7706 Peter Rosin 2016-04-20 348
a7ab72390b7706 Peter Rosin 2016-04-20 349 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
0826374bff5741 Michael Lawnick 2010-08-11 350 if (!priv)
a7ab72390b7706 Peter Rosin 2016-04-20 351 return -ENOMEM;
0826374bff5741 Michael Lawnick 2010-08-11 352
0826374bff5741 Michael Lawnick 2010-08-11 353 /* Set up private adapter data */
a7ab72390b7706 Peter Rosin 2016-04-20 354 priv->muxc = muxc;
0826374bff5741 Michael Lawnick 2010-08-11 355 priv->chan_id = chan_id;
0826374bff5741 Michael Lawnick 2010-08-11 356
0826374bff5741 Michael Lawnick 2010-08-11 357 /* Need to do algo dynamically because we don't know ahead
0826374bff5741 Michael Lawnick 2010-08-11 358 * of time what sort of physical adapter we'll be dealing with.
0826374bff5741 Michael Lawnick 2010-08-11 359 */
6ef91fcca8a8ba Peter Rosin 2016-05-04 360 if (parent->algo->master_xfer) {
6ef91fcca8a8ba Peter Rosin 2016-05-04 361 if (muxc->mux_locked)
614b1c3cbfb0ec Wolfram Sang 2025-06-12 362 priv->algo.xfer = i2c_mux_master_xfer;
6ef91fcca8a8ba Peter Rosin 2016-05-04 363 else
614b1c3cbfb0ec Wolfram Sang 2025-06-12 364 priv->algo.xfer = __i2c_mux_master_xfer;
6ef91fcca8a8ba Peter Rosin 2016-05-04 365 }
7168bff2cfd710 Wolfram Sang 2019-04-03 366 if (parent->algo->master_xfer_atomic)
614b1c3cbfb0ec Wolfram Sang 2025-06-12 367 priv->algo.xfer_atomic = priv->algo.master_xfer;
7168bff2cfd710 Wolfram Sang 2019-04-03 368
6ef91fcca8a8ba Peter Rosin 2016-05-04 369 if (parent->algo->smbus_xfer) {
6ef91fcca8a8ba Peter Rosin 2016-05-04 370 if (muxc->mux_locked)
0826374bff5741 Michael Lawnick 2010-08-11 371 priv->algo.smbus_xfer = i2c_mux_smbus_xfer;
6ef91fcca8a8ba Peter Rosin 2016-05-04 372 else
6ef91fcca8a8ba Peter Rosin 2016-05-04 373 priv->algo.smbus_xfer = __i2c_mux_smbus_xfer;
6ef91fcca8a8ba Peter Rosin 2016-05-04 374 }
7168bff2cfd710 Wolfram Sang 2019-04-03 375 if (parent->algo->smbus_xfer_atomic)
7168bff2cfd710 Wolfram Sang 2019-04-03 376 priv->algo.smbus_xfer_atomic = priv->algo.smbus_xfer;
7168bff2cfd710 Wolfram Sang 2019-04-03 377
0826374bff5741 Michael Lawnick 2010-08-11 378 priv->algo.functionality = i2c_mux_functionality;
0826374bff5741 Michael Lawnick 2010-08-11 379
0826374bff5741 Michael Lawnick 2010-08-11 380 /* Now fill out new adapter structure */
0826374bff5741 Michael Lawnick 2010-08-11 381 snprintf(priv->adap.name, sizeof(priv->adap.name),
0826374bff5741 Michael Lawnick 2010-08-11 382 "i2c-%d-mux (chan_id %d)", i2c_adapter_id(parent), chan_id);
0826374bff5741 Michael Lawnick 2010-08-11 383 priv->adap.owner = THIS_MODULE;
0826374bff5741 Michael Lawnick 2010-08-11 384 priv->adap.algo = &priv->algo;
0826374bff5741 Michael Lawnick 2010-08-11 385 priv->adap.algo_data = priv;
0826374bff5741 Michael Lawnick 2010-08-11 386 priv->adap.dev.parent = &parent->dev;
2212a8529eb06c Elie De Brauwer 2013-12-09 387 priv->adap.retries = parent->retries;
2212a8529eb06c Elie De Brauwer 2013-12-09 388 priv->adap.timeout = parent->timeout;
dc362d50ba94ea Alexander Sverdlin 2015-06-12 389 priv->adap.quirks = parent->quirks;
d1ed7985b9a6b8 Peter Rosin 2016-08-25 390 if (muxc->mux_locked)
d1ed7985b9a6b8 Peter Rosin 2016-08-25 391 priv->adap.lock_ops = &i2c_mux_lock_ops;
d1ed7985b9a6b8 Peter Rosin 2016-08-25 392 else
d1ed7985b9a6b8 Peter Rosin 2016-08-25 393 priv->adap.lock_ops = &i2c_parent_lock_ops;
0826374bff5741 Michael Lawnick 2010-08-11 394
bc45449b144461 David Daney 2012-04-12 395 /*
bc45449b144461 David Daney 2012-04-12 396 * Try to populate the mux adapter's of_node, expands to
bc45449b144461 David Daney 2012-04-12 397 * nothing if !CONFIG_OF.
bc45449b144461 David Daney 2012-04-12 398 */
a7ab72390b7706 Peter Rosin 2016-04-20 399 if (muxc->dev->of_node) {
b2d57b56047b99 Peter Rosin 2016-07-09 400 struct device_node *dev_node = muxc->dev->of_node;
b2d57b56047b99 Peter Rosin 2016-07-09 401 struct device_node *mux_node, *child = NULL;
bc45449b144461 David Daney 2012-04-12 402 u32 reg;
bc45449b144461 David Daney 2012-04-12 403
b2d57b56047b99 Peter Rosin 2016-07-09 404 if (muxc->arbitrator)
b2d57b56047b99 Peter Rosin 2016-07-09 405 mux_node = of_get_child_by_name(dev_node, "i2c-arb");
b2d57b56047b99 Peter Rosin 2016-07-09 406 else if (muxc->gate)
b2d57b56047b99 Peter Rosin 2016-07-09 407 mux_node = of_get_child_by_name(dev_node, "i2c-gate");
b2d57b56047b99 Peter Rosin 2016-07-09 408 else
b2d57b56047b99 Peter Rosin 2016-07-09 409 mux_node = of_get_child_by_name(dev_node, "i2c-mux");
b2d57b56047b99 Peter Rosin 2016-07-09 410
b2d57b56047b99 Peter Rosin 2016-07-09 411 if (mux_node) {
b2d57b56047b99 Peter Rosin 2016-07-09 412 /* A "reg" property indicates an old-style DT entry */
b2d57b56047b99 Peter Rosin 2016-07-09 413 if (!of_property_read_u32(mux_node, "reg", ®)) {
b2d57b56047b99 Peter Rosin 2016-07-09 414 of_node_put(mux_node);
b2d57b56047b99 Peter Rosin 2016-07-09 415 mux_node = NULL;
b2d57b56047b99 Peter Rosin 2016-07-09 416 }
b2d57b56047b99 Peter Rosin 2016-07-09 417 }
b2d57b56047b99 Peter Rosin 2016-07-09 418
b2d57b56047b99 Peter Rosin 2016-07-09 419 if (!mux_node)
b2d57b56047b99 Peter Rosin 2016-07-09 420 mux_node = of_node_get(dev_node);
b2d57b56047b99 Peter Rosin 2016-07-09 421 else if (muxc->arbitrator || muxc->gate)
b2d57b56047b99 Peter Rosin 2016-07-09 422 child = of_node_get(mux_node);
b2d57b56047b99 Peter Rosin 2016-07-09 423
b2d57b56047b99 Peter Rosin 2016-07-09 424 if (!child) {
b2d57b56047b99 Peter Rosin 2016-07-09 425 for_each_child_of_node(mux_node, child) {
bc45449b144461 David Daney 2012-04-12 426 ret = of_property_read_u32(child, "reg", ®);
bc45449b144461 David Daney 2012-04-12 427 if (ret)
bc45449b144461 David Daney 2012-04-12 428 continue;
b2d57b56047b99 Peter Rosin 2016-07-09 429 if (chan_id == reg)
bc45449b144461 David Daney 2012-04-12 430 break;
bc45449b144461 David Daney 2012-04-12 431 }
64f0150a54ef60 Marcus Folkesson 2025-10-02 432 }
64f0150a54ef60 Marcus Folkesson 2025-10-02 433
64f0150a54ef60 Marcus Folkesson 2025-10-02 434 of_property_read_u32(child, "clock-frequency", &priv->adap.clock_hz);
64f0150a54ef60 Marcus Folkesson 2025-10-02 435
64f0150a54ef60 Marcus Folkesson 2025-10-02 436 /*
64f0150a54ef60 Marcus Folkesson 2025-10-02 437 * Warn if the mux adapter is not parent-locked as
64f0150a54ef60 Marcus Folkesson 2025-10-02 438 * this may cause issues for some hardware topologies.
64f0150a54ef60 Marcus Folkesson 2025-10-02 439 */
64f0150a54ef60 Marcus Folkesson 2025-10-02 440 if ((priv->adap.clock_hz < parent->clock_hz) && muxc->mux_locked)
64f0150a54ef60 Marcus Folkesson 2025-10-02 441 dev_warn(muxc->dev,
64f0150a54ef60 Marcus Folkesson 2025-10-02 442 "channel %u is slower than parent on a non parent-locked mux\n",
64f0150a54ef60 Marcus Folkesson 2025-10-02 443 chan_id);
64f0150a54ef60 Marcus Folkesson 2025-10-02 444
64f0150a54ef60 Marcus Folkesson 2025-10-02 445 /* If the mux adapter has no clock-frequency property, inherit from parent */
64f0150a54ef60 Marcus Folkesson 2025-10-02 446 if (!priv->adap.clock_hz)
64f0150a54ef60 Marcus Folkesson 2025-10-02 447 priv->adap.clock_hz = parent->clock_hz;
64f0150a54ef60 Marcus Folkesson 2025-10-02 448
64f0150a54ef60 Marcus Folkesson 2025-10-02 449 /* We don't support mux adapters faster than their parent */
64f0150a54ef60 Marcus Folkesson 2025-10-02 450 if (priv->adap.clock_hz > parent->clock_hz) {
64f0150a54ef60 Marcus Folkesson 2025-10-02 451 dev_err(muxc->dev,
64f0150a54ef60 Marcus Folkesson 2025-10-02 452 "channel (%u) is faster (%u) than parent (%u)\n",
64f0150a54ef60 Marcus Folkesson 2025-10-02 453 chan_id, priv->adap.clock_hz, parent->clock_hz);
64f0150a54ef60 Marcus Folkesson 2025-10-02 454
64f0150a54ef60 Marcus Folkesson 2025-10-02 455 of_node_put(mux_node);
64f0150a54ef60 Marcus Folkesson 2025-10-02 456 goto err_free_priv;
ret = -EINVAL;
bc45449b144461 David Daney 2012-04-12 457 }
b2d57b56047b99 Peter Rosin 2016-07-09 458
b2d57b56047b99 Peter Rosin 2016-07-09 459 priv->adap.dev.of_node = child;
b2d57b56047b99 Peter Rosin 2016-07-09 460 of_node_put(mux_node);
bc45449b144461 David Daney 2012-04-12 461 }
bc45449b144461 David Daney 2012-04-12 462
8eb5c87a92c065 Dustin Byford 2015-10-23 463 /*
8eb5c87a92c065 Dustin Byford 2015-10-23 464 * Associate the mux channel with an ACPI node.
8eb5c87a92c065 Dustin Byford 2015-10-23 465 */
a7ab72390b7706 Peter Rosin 2016-04-20 466 if (has_acpi_companion(muxc->dev))
a7ab72390b7706 Peter Rosin 2016-04-20 467 acpi_preset_companion(&priv->adap.dev,
a7ab72390b7706 Peter Rosin 2016-04-20 468 ACPI_COMPANION(muxc->dev),
8eb5c87a92c065 Dustin Byford 2015-10-23 469 chan_id);
8eb5c87a92c065 Dustin Byford 2015-10-23 470
0826374bff5741 Michael Lawnick 2010-08-11 471 if (force_nr) {
0826374bff5741 Michael Lawnick 2010-08-11 472 priv->adap.nr = force_nr;
0826374bff5741 Michael Lawnick 2010-08-11 473 ret = i2c_add_numbered_adapter(&priv->adap);
9fce894d03a98e Peter Rosin 2017-05-15 474 if (ret < 0) {
8d4d159f25a79b Peter Rosin 2017-04-03 475 dev_err(&parent->dev,
8d4d159f25a79b Peter Rosin 2017-04-03 476 "failed to add mux-adapter %u as bus %u (error=%d)\n",
8d4d159f25a79b Peter Rosin 2017-04-03 477 chan_id, force_nr, ret);
9fce894d03a98e Peter Rosin 2017-05-15 478 goto err_free_priv;
9fce894d03a98e Peter Rosin 2017-05-15 479 }
0826374bff5741 Michael Lawnick 2010-08-11 480 } else {
0826374bff5741 Michael Lawnick 2010-08-11 481 ret = i2c_add_adapter(&priv->adap);
9fce894d03a98e Peter Rosin 2017-05-15 482 if (ret < 0) {
8d4d159f25a79b Peter Rosin 2017-04-03 483 dev_err(&parent->dev,
8d4d159f25a79b Peter Rosin 2017-04-03 484 "failed to add mux-adapter %u (error=%d)\n",
8d4d159f25a79b Peter Rosin 2017-04-03 485 chan_id, ret);
9fce894d03a98e Peter Rosin 2017-05-15 486 goto err_free_priv;
0826374bff5741 Michael Lawnick 2010-08-11 487 }
0826374bff5741 Michael Lawnick 2010-08-11 488 }
0826374bff5741 Michael Lawnick 2010-08-11 489
a7ab72390b7706 Peter Rosin 2016-04-20 490 WARN(sysfs_create_link(&priv->adap.dev.kobj, &muxc->dev->kobj,
a7ab72390b7706 Peter Rosin 2016-04-20 491 "mux_device"),
51cf3b0e2a72bb Wolfram Sang 2014-11-13 492 "can't create symlink to mux device\n");
51cf3b0e2a72bb Wolfram Sang 2014-11-13 493
c9449affad2ae0 Gerlando Falauto 2014-11-13 494 snprintf(symlink_name, sizeof(symlink_name), "channel-%u", chan_id);
a7ab72390b7706 Peter Rosin 2016-04-20 495 WARN(sysfs_create_link(&muxc->dev->kobj, &priv->adap.dev.kobj,
a7ab72390b7706 Peter Rosin 2016-04-20 496 symlink_name),
f657c9fe268882 Wolfram Sang 2018-05-21 497 "can't create symlink to channel %u\n", chan_id);
0826374bff5741 Michael Lawnick 2010-08-11 498 dev_info(&parent->dev, "Added multiplexed i2c bus %d\n",
0826374bff5741 Michael Lawnick 2010-08-11 499 i2c_adapter_id(&priv->adap));
0826374bff5741 Michael Lawnick 2010-08-11 500
a7ab72390b7706 Peter Rosin 2016-04-20 501 muxc->adapter[muxc->num_adapters++] = &priv->adap;
a7ab72390b7706 Peter Rosin 2016-04-20 502 return 0;
9fce894d03a98e Peter Rosin 2017-05-15 503
9fce894d03a98e Peter Rosin 2017-05-15 504 err_free_priv:
9fce894d03a98e Peter Rosin 2017-05-15 505 kfree(priv);
9fce894d03a98e Peter Rosin 2017-05-15 @506 return ret;
0826374bff5741 Michael Lawnick 2010-08-11 507 }
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next prev parent reply other threads:[~2025-10-03 10:57 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-02 14:41 [PATCH v2 0/5] I2C Mux per channel bus speed Marcus Folkesson
2025-10-02 14:41 ` [PATCH v2 1/5] i2c: core: add callback to change bus frequency Marcus Folkesson
2025-10-02 14:41 ` [PATCH v2 2/5] i2c: mux: add support for per channel " Marcus Folkesson
2025-10-03 10:57 ` Dan Carpenter [this message]
2025-10-02 14:41 ` [PATCH v2 3/5] i2c: davinci: calculate bus freq from Hz instead of kHz Marcus Folkesson
2025-10-02 14:49 ` Bartosz Golaszewski
2025-10-02 14:41 ` [PATCH v2 4/5] i2c: davinci: add support for setting bus frequency Marcus Folkesson
2025-10-02 14:41 ` [PATCH v2 5/5] docs: i2c: i2c-topology: add section about bus speed Marcus Folkesson
2025-10-14 14:13 ` [PATCH v2 0/5] I2C Mux per channel " Marcus Folkesson
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