Re: [PATCH v3 1/3] usb: core: hcd: Add support for deferring roothub registration

From: kernel test robot
Date: Wed Sep 08 2021 - 11:47:13 EST


Hi Kishon,

I love your patch! Perhaps something to improve:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on v5.14 next-20210908]
[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/Kishon-Vijay-Abraham-I/Fix-cold-plugged-USB-device-on-certain-PCIe-USB-cards/20210908-175547
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
config: riscv-randconfig-r012-20210908 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 9c476172b93367d2cb88d7d3f4b1b5b456fa6020)
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/03e83cc595ea0a47e7f25c7d7b541d704b06932c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Kishon-Vijay-Abraham-I/Fix-cold-plugged-USB-device-on-certain-PCIe-USB-cards/20210908-175547
git checkout 03e83cc595ea0a47e7f25c7d7b541d704b06932c
# 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 >>):

In file included from drivers/usb/core/hcd.c:21:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
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/usb/core/hcd.c:21:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
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/usb/core/hcd.c:21:
In file included from arch/riscv/include/asm/io.h:136:
include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:1024:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
~~~~~~~~~~ ^
>> drivers/usb/core/hcd.c:3013:6: warning: variable 'rh_registered' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
if (hcd->rh_registered == 1)
^~~~~~~~~~~~~~~~~~~~~~~
drivers/usb/core/hcd.c:3024:6: note: uninitialized use occurs here
if (rh_registered == 1)
^~~~~~~~~~~~~
drivers/usb/core/hcd.c:3013:2: note: remove the 'if' if its condition is always true
if (hcd->rh_registered == 1)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/usb/core/hcd.c:3002:24: note: initialize the variable 'rh_registered' to silence this warning
unsigned rh_registered;
^
= 0
8 warnings generated.


vim +3013 drivers/usb/core/hcd.c

2989
2990 /**
2991 * usb_remove_hcd - shutdown processing for generic HCDs
2992 * @hcd: the usb_hcd structure to remove
2993 *
2994 * Context: task context, might sleep.
2995 *
2996 * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2997 * invoking the HCD's stop() method.
2998 */
2999 void usb_remove_hcd(struct usb_hcd *hcd)
3000 {
3001 struct usb_device *rhdev = hcd->self.root_hub;
3002 unsigned rh_registered;
3003
3004 dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
3005
3006 usb_get_dev(rhdev);
3007 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
3008 if (HC_IS_RUNNING (hcd->state))
3009 hcd->state = HC_STATE_QUIESCING;
3010
3011 dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
3012 spin_lock_irq (&hcd_root_hub_lock);
> 3013 if (hcd->rh_registered == 1)
3014 rh_registered = 1;
3015 hcd->rh_registered = 0;
3016 spin_unlock_irq (&hcd_root_hub_lock);
3017

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

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