Re: [PATCH v1 4/5] driver core: Handle cycles in device links created by fw_devlink

From: kernel test robot
Date: Fri Dec 18 2020 - 02:14:38 EST

Hi Saravana,

I love your patch! Perhaps something to improve:

[auto build test WARNING on driver-core/driver-core-testing]
[also build test WARNING on linus/master next-20201217]
[cannot apply to linux/master v5.10]
[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]

url: https://github.com/0day-ci/linux/commits/Saravana-Kannan/Enable-fw_devlink-on-by-default/20201218-112111
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git accefff5b547a9a1d959c7e76ad539bf2480e78b
config: riscv-randconfig-r014-20201217 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project cee1e7d14f4628d6174b33640d502bff3b54ae45)
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 riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://github.com/0day-ci/linux/commit/7bdc87ea0400318d827410f454ec7e5fbaf470c3
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Saravana-Kannan/Enable-fw_devlink-on-by-default/20201218-112111
git checkout 7bdc87ea0400318d827410f454ec7e5fbaf470c3
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv

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

All warnings (new ones prefixed by >>):

~~~~~~~~~~ ^
arch/riscv/include/asm/mmio.h:87:48: note: expanded from macro 'readb_cpu'
#define readb_cpu(c) ({ u8 __r = __raw_readb(c); __r; })
^
In file included from drivers/base/core.c:27:
In file included from include/linux/netdevice.h:37:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/riscv/include/asm/io.h:149:
include/asm-generic/io.h:564:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return inw(addr);
^~~~~~~~~
arch/riscv/include/asm/io.h:56:76: note: expanded from macro 'inw'
#define inw(c) ({ u16 __v; __io_pbr(); __v = readw_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
~~~~~~~~~~ ^
arch/riscv/include/asm/mmio.h:88:76: note: expanded from macro 'readw_cpu'
#define readw_cpu(c) ({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; })
^
include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
^
In file included from drivers/base/core.c:27:
In file included from include/linux/netdevice.h:37:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/riscv/include/asm/io.h:149:
include/asm-generic/io.h:572:9: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return inl(addr);
^~~~~~~~~
arch/riscv/include/asm/io.h:57:76: note: expanded from macro 'inl'
#define inl(c) ({ u32 __v; __io_pbr(); __v = readl_cpu((void*)(PCI_IOBASE + (c))); __io_par(__v); __v; })
~~~~~~~~~~ ^
arch/riscv/include/asm/mmio.h:89:76: note: expanded from macro 'readl_cpu'
#define readl_cpu(c) ({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; })
^
include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
In file included from drivers/base/core.c:27:
In file included from include/linux/netdevice.h:37:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/riscv/include/asm/io.h:149:
include/asm-generic/io.h:580:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
outb(value, addr);
^~~~~~~~~~~~~~~~~
arch/riscv/include/asm/io.h:59:68: note: expanded from macro 'outb'
#define outb(v,c) ({ __io_pbw(); writeb_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
~~~~~~~~~~ ^
arch/riscv/include/asm/mmio.h:91:52: note: expanded from macro 'writeb_cpu'
#define writeb_cpu(v, c) ((void)__raw_writeb((v), (c)))
^
In file included from drivers/base/core.c:27:
In file included from include/linux/netdevice.h:37:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/riscv/include/asm/io.h:149:
include/asm-generic/io.h:588:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
outw(value, addr);
^~~~~~~~~~~~~~~~~
arch/riscv/include/asm/io.h:60:68: note: expanded from macro 'outw'
#define outw(v,c) ({ __io_pbw(); writew_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
~~~~~~~~~~ ^
arch/riscv/include/asm/mmio.h:92:76: note: expanded from macro 'writew_cpu'
#define writew_cpu(v, c) ((void)__raw_writew((__force u16)cpu_to_le16(v), (c)))
^
In file included from drivers/base/core.c:27:
In file included from include/linux/netdevice.h:37:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/riscv/include/asm/io.h:149:
include/asm-generic/io.h:596:2: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
outl(value, addr);
^~~~~~~~~~~~~~~~~
arch/riscv/include/asm/io.h:61:68: note: expanded from macro 'outl'
#define outl(v,c) ({ __io_pbw(); writel_cpu((v),(void*)(PCI_IOBASE + (c))); __io_paw(); })
~~~~~~~~~~ ^
arch/riscv/include/asm/mmio.h:93:76: note: expanded from macro 'writel_cpu'
#define writel_cpu(v, c) ((void)__raw_writel((__force u32)cpu_to_le32(v), (c)))
^
In file included from drivers/base/core.c:27:
In file included from include/linux/netdevice.h:37:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:10:
In file included from include/linux/scatterlist.h:9:
In file included from arch/riscv/include/asm/io.h:149:
include/asm-generic/io.h:1005:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
~~~~~~~~~~ ^
>> drivers/base/core.c:1522:5: warning: no previous prototype for function 'fw_devlink_relax_cycle' [-Wmissing-prototypes]
int fw_devlink_relax_cycle(struct device *con, void *sup)
^
drivers/base/core.c:1522:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int fw_devlink_relax_cycle(struct device *con, void *sup)
^
static
8 warnings generated.


vim +/fw_devlink_relax_cycle +1522 drivers/base/core.c

1507
1508 /**
1509 * fw_devlink_relax_cycle - Convert cyclic links to SYNC_STATE_ONLY links
1510 * @con: Device to check dependencies for.
1511 * @sup: Device to check against.
1512 *
1513 * Check if @sup depends on @con or any device dependent on it (its child or
1514 * its consumer etc). When such a cyclic dependency is found, convert all
1515 * device links created solely by fw_devlink into SYNC_STATE_ONLY device links.
1516 * This is the equivalent of doing fw_devlink=permissive just between the
1517 * devices in the cycle. We need to do this because, at this point, fw_devlink
1518 * can't tell which of these dependencies is not a real dependency.
1519 *
1520 * Return 1 if a cycle is found. Otherwise, return 0.
1521 */
> 1522 int fw_devlink_relax_cycle(struct device *con, void *sup)
1523 {
1524 struct device_link *link;
1525 int ret;
1526
1527 if (con == sup)
1528 return 1;
1529
1530 ret = device_for_each_child(con, sup, fw_devlink_relax_cycle);
1531 if (ret)
1532 return ret;
1533
1534 list_for_each_entry(link, &con->links.consumers, s_node) {
1535 if ((link->flags & ~DL_FLAG_INFERRED) ==
1536 (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
1537 continue;
1538
1539 if (!fw_devlink_relax_cycle(link->consumer, sup))
1540 continue;
1541
1542 ret = 1;
1543
1544 if (!(link->flags & DL_FLAG_INFERRED))
1545 continue;
1546
1547 pm_runtime_drop_link(link);
1548 link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE;
1549 dev_dbg(link->consumer, "Relaxing link with %s\n",
1550 dev_name(link->supplier));
1551 }
1552 return ret;
1553 }
1554

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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