[lunn:dsa-ci 22/47] drivers/net/phy/mdio_bus.c:710:9: warning: The expression is an uninitialized value. The computed value will also be garbage [clang-analyzer-core.uninitialized.Assign]

From: kernel test robot
Date: Mon May 09 2022 - 01:57:25 EST


tree: https://github.com/lunn/linux.git dsa-ci
head: 1149273e5c97f04e2255421372a8a30c75c0b842
commit: e582444c20a13a52eabf1d982d1f7e96344be2a8 [22/47] net: mdiobus: Rework scanning of bus ready for quirks
config: i386-randconfig-c001 (https://download.01.org/0day-ci/archive/20220504/202205042049.SwDh4zxv-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 09325d36061e42b495d1f4c7e933e260eac260ed)
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
# https://github.com/lunn/linux/commit/e582444c20a13a52eabf1d982d1f7e96344be2a8
git remote add lunn https://github.com/lunn/linux.git
git fetch --no-tags lunn dsa-ci
git checkout e582444c20a13a52eabf1d982d1f7e96344be2a8
# save the config file
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=i386 clang-analyzer

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


clang-analyzer warnings: (new ones prefixed by >>)

>> drivers/net/phy/mdio_bus.c:710:9: warning: The expression is an uninitialized value. The computed value will also be garbage [clang-analyzer-core.uninitialized.Assign]
while (--i >= 0) {
^ ~
drivers/net/phy/mdio_bus.c:621:6: note: 'i' declared without an initial value
int i, err;
^

vim +710 drivers/net/phy/mdio_bus.c

4ed8df519849887 Andrew Lunn 2022-04-20 603
b3df0da886ffdb3 Randy Dunlap 2007-03-06 604 /**
59f069789c98678 Russell King 2015-09-25 605 * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
b3df0da886ffdb3 Randy Dunlap 2007-03-06 606 * @bus: target mii_bus
59f069789c98678 Russell King 2015-09-25 607 * @owner: module containing bus accessor functions
e13934563db0470 Andy Fleming 2005-08-24 608 *
b3df0da886ffdb3 Randy Dunlap 2007-03-06 609 * Description: Called by a bus driver to bring up all the PHYs
59f069789c98678 Russell King 2015-09-25 610 * on a given bus, and attach them to the bus. Drivers should use
59f069789c98678 Russell King 2015-09-25 611 * mdiobus_register() rather than __mdiobus_register() unless they
f89df3f381f1e12 Andrew Lunn 2016-01-06 612 * need to pass a specific owner module. MDIO devices which are not
fec76125baf7390 Peng Li 2021-03-30 613 * PHYs will not be brought up by this function. They are expected
f89df3f381f1e12 Andrew Lunn 2016-01-06 614 * to be explicitly listed in DT and instantiated by of_mdiobus_register().
b3df0da886ffdb3 Randy Dunlap 2007-03-06 615 *
b3df0da886ffdb3 Randy Dunlap 2007-03-06 616 * Returns 0 on success or < 0 on error.
e13934563db0470 Andy Fleming 2005-08-24 617 */
3e3aaf649416988 Russell King 2015-09-24 618 int __mdiobus_register(struct mii_bus *bus, struct module *owner)
e13934563db0470 Andy Fleming 2005-08-24 619 {
711fdba37a3dd7e Andrew Lunn 2016-01-06 620 struct mdio_device *mdiodev;
161c8d2f50109b4 Krzysztof Halasa 2008-12-25 @621 int i, err;
69226896ad636b9 Roger Quadros 2017-04-21 622 struct gpio_desc *gpiod;
e13934563db0470 Andy Fleming 2005-08-24 623
effd7e805c90de8 Andrew Lunn 2022-04-02 624 if (NULL == bus || NULL == bus->name)
effd7e805c90de8 Andrew Lunn 2022-04-02 625 return -EINVAL;
effd7e805c90de8 Andrew Lunn 2022-04-02 626
effd7e805c90de8 Andrew Lunn 2022-04-02 627 if (!bus->read != !bus->write)
effd7e805c90de8 Andrew Lunn 2022-04-02 628 return -EINVAL;
effd7e805c90de8 Andrew Lunn 2022-04-02 629
effd7e805c90de8 Andrew Lunn 2022-04-02 630 if (!bus->read_c45 != !bus->write_c45)
effd7e805c90de8 Andrew Lunn 2022-04-02 631 return -EINVAL;
effd7e805c90de8 Andrew Lunn 2022-04-02 632
effd7e805c90de8 Andrew Lunn 2022-04-02 633 if (!bus->read && !bus->read_c45)
e13934563db0470 Andy Fleming 2005-08-24 634 return -EINVAL;
e13934563db0470 Andy Fleming 2005-08-24 635
04f41c68f18886a Saravana Kannan 2021-09-15 636 if (bus->parent && bus->parent->of_node)
04f41c68f18886a Saravana Kannan 2021-09-15 637 bus->parent->of_node->fwnode.flags |=
04f41c68f18886a Saravana Kannan 2021-09-15 638 FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;
04f41c68f18886a Saravana Kannan 2021-09-15 639
867ae8a7993b26f Florian Fainelli 2021-11-17 640 WARN(bus->state != MDIOBUS_ALLOCATED &&
867ae8a7993b26f Florian Fainelli 2021-11-17 641 bus->state != MDIOBUS_UNREGISTERED,
867ae8a7993b26f Florian Fainelli 2021-11-17 642 "%s: not in ALLOCATED or UNREGISTERED state\n", bus->id);
46abc02175b3c24 Lennert Buytenhek 2008-10-08 643
3e3aaf649416988 Russell King 2015-09-24 644 bus->owner = owner;
46abc02175b3c24 Lennert Buytenhek 2008-10-08 645 bus->dev.parent = bus->parent;
46abc02175b3c24 Lennert Buytenhek 2008-10-08 646 bus->dev.class = &mdio_bus_class;
46abc02175b3c24 Lennert Buytenhek 2008-10-08 647 bus->dev.groups = NULL;
036b66879addb28 Stephen Hemminger 2009-02-26 648 dev_set_name(&bus->dev, "%s", bus->id);
46abc02175b3c24 Lennert Buytenhek 2008-10-08 649
ca6e11c337daf79 Pavel Skripkin 2021-09-30 650 /* We need to set state to MDIOBUS_UNREGISTERED to correctly release
ca6e11c337daf79 Pavel Skripkin 2021-09-30 651 * the device in mdiobus_free()
ca6e11c337daf79 Pavel Skripkin 2021-09-30 652 *
ca6e11c337daf79 Pavel Skripkin 2021-09-30 653 * State will be updated later in this function in case of success
ca6e11c337daf79 Pavel Skripkin 2021-09-30 654 */
ca6e11c337daf79 Pavel Skripkin 2021-09-30 655 bus->state = MDIOBUS_UNREGISTERED;
ca6e11c337daf79 Pavel Skripkin 2021-09-30 656
46abc02175b3c24 Lennert Buytenhek 2008-10-08 657 err = device_register(&bus->dev);
46abc02175b3c24 Lennert Buytenhek 2008-10-08 658 if (err) {
8d242488ce4627d Joe Perches 2012-06-09 659 pr_err("mii_bus %s failed to register\n", bus->id);
46abc02175b3c24 Lennert Buytenhek 2008-10-08 660 return -EINVAL;
46abc02175b3c24 Lennert Buytenhek 2008-10-08 661 }
46abc02175b3c24 Lennert Buytenhek 2008-10-08 662
d1e7fe4d92742dd Adrian Bunk 2008-02-20 663 mutex_init(&bus->mdio_lock);
6349084746ff4f5 Michael Walle 2020-05-06 664 mutex_init(&bus->shared_lock);
d1e7fe4d92742dd Adrian Bunk 2008-02-20 665
e0183b974d3008a Mike Looijmans 2021-02-02 666 /* assert bus level PHY GPIO reset */
e0183b974d3008a Mike Looijmans 2021-02-02 667 gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_HIGH);
69226896ad636b9 Roger Quadros 2017-04-21 668 if (IS_ERR(gpiod)) {
0a12ad592955619 Grygorii Strashko 2020-11-19 669 err = dev_err_probe(&bus->dev, PTR_ERR(gpiod),
0a12ad592955619 Grygorii Strashko 2020-11-19 670 "mii_bus %s couldn't get reset GPIO\n",
69226896ad636b9 Roger Quadros 2017-04-21 671 bus->id);
e40e2a2e78664fa Thomas Petazzoni 2019-01-16 672 device_del(&bus->dev);
0a12ad592955619 Grygorii Strashko 2020-11-19 673 return err;
fe0e4052fb11d5c Sergei Shtylyov 2017-06-12 674 } else if (gpiod) {
d396e84c56047b3 Sergei Shtylyov 2017-06-12 675 bus->reset_gpiod = gpiod;
6259e0f5478d7a7 Bruno Thomsen 2020-07-30 676 fsleep(bus->reset_delay_us);
69226896ad636b9 Roger Quadros 2017-04-21 677 gpiod_set_value_cansleep(gpiod, 0);
bb3831294cd5075 Bruno Thomsen 2020-07-30 678 if (bus->reset_post_delay_us > 0)
bb3831294cd5075 Bruno Thomsen 2020-07-30 679 fsleep(bus->reset_post_delay_us);
69226896ad636b9 Roger Quadros 2017-04-21 680 }
69226896ad636b9 Roger Quadros 2017-04-21 681
c290d1ab12d3385 Florian Fainelli 2020-04-18 682 if (bus->reset) {
c290d1ab12d3385 Florian Fainelli 2020-04-18 683 err = bus->reset(bus);
c290d1ab12d3385 Florian Fainelli 2020-04-18 684 if (err)
c290d1ab12d3385 Florian Fainelli 2020-04-18 685 goto error_reset_gpiod;
c290d1ab12d3385 Florian Fainelli 2020-04-18 686 }
df0c8d911abf6ba Florian Fainelli 2017-05-11 687
e582444c20a13a5 Andrew Lunn 2022-04-20 688 if (bus->probe_capabilities == MDIOBUS_NO_CAP ||
e582444c20a13a5 Andrew Lunn 2022-04-20 689 bus->probe_capabilities == MDIOBUS_C22 ||
e582444c20a13a5 Andrew Lunn 2022-04-20 690 bus->probe_capabilities == MDIOBUS_C22_C45) {
e582444c20a13a5 Andrew Lunn 2022-04-20 691 err = mdiobus_scan_bus_c22(bus);
e582444c20a13a5 Andrew Lunn 2022-04-20 692 if (err)
161c8d2f50109b4 Krzysztof Halasa 2008-12-25 693 goto error;
161c8d2f50109b4 Krzysztof Halasa 2008-12-25 694 }
e582444c20a13a5 Andrew Lunn 2022-04-20 695
e582444c20a13a5 Andrew Lunn 2022-04-20 696 if (bus->probe_capabilities == MDIOBUS_C45 ||
e582444c20a13a5 Andrew Lunn 2022-04-20 697 bus->probe_capabilities == MDIOBUS_C22_C45) {
e582444c20a13a5 Andrew Lunn 2022-04-20 698 err = mdiobus_scan_bus_c45(bus);
e582444c20a13a5 Andrew Lunn 2022-04-20 699 if (err)
e582444c20a13a5 Andrew Lunn 2022-04-20 700 goto error;
64b1c2b42b555ef Herbert Valerio Riedel 2006-05-10 701 }
f896424cbc61225 Matt Porter 2005-11-02 702
d0281a56b00c63a Florian Fainelli 2017-03-28 703 mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
648ea0134069cda Florian Fainelli 2017-02-04 704
e8e5752dc0a56a0 Krzysztof Halasa 2008-12-17 705 bus->state = MDIOBUS_REGISTERED;
7590fc6f80ac2cb Florian Fainelli 2022-01-03 706 dev_dbg(&bus->dev, "probed\n");
161c8d2f50109b4 Krzysztof Halasa 2008-12-25 707 return 0;
e13934563db0470 Andy Fleming 2005-08-24 708
161c8d2f50109b4 Krzysztof Halasa 2008-12-25 709 error:
161c8d2f50109b4 Krzysztof Halasa 2008-12-25 @710 while (--i >= 0) {
711fdba37a3dd7e Andrew Lunn 2016-01-06 711 mdiodev = bus->mdio_map[i];
711fdba37a3dd7e Andrew Lunn 2016-01-06 712 if (!mdiodev)
711fdba37a3dd7e Andrew Lunn 2016-01-06 713 continue;
711fdba37a3dd7e Andrew Lunn 2016-01-06 714
711fdba37a3dd7e Andrew Lunn 2016-01-06 715 mdiodev->device_remove(mdiodev);
711fdba37a3dd7e Andrew Lunn 2016-01-06 716 mdiodev->device_free(mdiodev);
161c8d2f50109b4 Krzysztof Halasa 2008-12-25 717 }
c290d1ab12d3385 Florian Fainelli 2020-04-18 718 error_reset_gpiod:
69226896ad636b9 Roger Quadros 2017-04-21 719 /* Put PHYs in RESET to save power */
a010a2f6540ecc3 Florian Fainelli 2017-09-08 720 if (bus->reset_gpiod)
d396e84c56047b3 Sergei Shtylyov 2017-06-12 721 gpiod_set_value_cansleep(bus->reset_gpiod, 1);
69226896ad636b9 Roger Quadros 2017-04-21 722
161c8d2f50109b4 Krzysztof Halasa 2008-12-25 723 device_del(&bus->dev);
4fd5f812c23c7de Lennert Buytenhek 2008-08-26 724 return err;
4fd5f812c23c7de Lennert Buytenhek 2008-08-26 725 }
3e3aaf649416988 Russell King 2015-09-24 726 EXPORT_SYMBOL(__mdiobus_register);
4fd5f812c23c7de Lennert Buytenhek 2008-08-26 727

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