Re: [PATCH] locking/rwsem: Convert the other sem->count to 'atomic_long_t'

From: kbuild test robot
Date: Tue Jul 10 2018 - 05:42:09 EST


Hi Tetsuo,

I love your patch! Perhaps something to improve:

[auto build test WARNING on tip/locking/core]
[also build test WARNING on v4.18-rc4 next-20180709]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Tetsuo-Handa/locking-rwsem-Convert-the-other-sem-count-to-atomic_long_t/20180710-141553
config: parisc-c3000_defconfig (attached as .config)
compiler: hppa-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
GCC_VERSION=7.2.0 make.cross ARCH=parisc

All warnings (new ones prefixed by >>):

In file included from include/linux/notifier.h:15:0,
from include/linux/memory_hotplug.h:7,
from include/linux/mmzone.h:777,
from include/linux/gfp.h:6,
from include/linux/umh.h:4,
from include/linux/kmod.h:22,
from include/linux/module.h:13,
from drivers/usb/core/hcd-pci.c:7:
include/linux/rwsem.h:87:2: warning: missing braces around initializer [-Wmissing-braces]
{ __RWSEM_INIT_COUNT(name), \
^
include/linux/rwsem.h:94:29: note: in expansion of macro '__RWSEM_INITIALIZER'
struct rw_semaphore name = __RWSEM_INITIALIZER(name)
^~~~~~~~~~~~~~~~~~~
>> drivers/usb/core/hcd-pci.c:31:8: note: in expansion of macro 'DECLARE_RWSEM'
static DECLARE_RWSEM(companions_rwsem);
^~~~~~~~~~~~~

vim +/DECLARE_RWSEM +31 drivers/usb/core/hcd-pci.c

^1da177e4 Linus Torvalds 2005-04-16 @7 #include <linux/module.h>
^1da177e4 Linus Torvalds 2005-04-16 8 #include <linux/pci.h>
21b1861fb David Brownell 2005-11-23 9 #include <linux/usb.h>
27729aadd Eric Lescouet 2010-04-24 10 #include <linux/usb/hcd.h>
21b1861fb David Brownell 2005-11-23 11
^1da177e4 Linus Torvalds 2005-04-16 12 #include <asm/io.h>
^1da177e4 Linus Torvalds 2005-04-16 13 #include <asm/irq.h>
21b1861fb David Brownell 2005-11-23 14
21b1861fb David Brownell 2005-11-23 15 #ifdef CONFIG_PPC_PMAC
21b1861fb David Brownell 2005-11-23 16 #include <asm/machdep.h>
21b1861fb David Brownell 2005-11-23 17 #include <asm/pmac_feature.h>
21b1861fb David Brownell 2005-11-23 18 #include <asm/prom.h>
21b1861fb David Brownell 2005-11-23 19 #endif
5f827ea3c David Brownell 2005-09-22 20
5f827ea3c David Brownell 2005-09-22 21 #include "usb.h"
^1da177e4 Linus Torvalds 2005-04-16 22
^1da177e4 Linus Torvalds 2005-04-16 23
c6053ecff David Brownell 2005-04-18 24 /* PCI-based HCs are common, but plenty of non-PCI HCs are used too */
^1da177e4 Linus Torvalds 2005-04-16 25
05768918b Alan Stern 2013-03-28 26 /*
05768918b Alan Stern 2013-03-28 27 * Coordinate handoffs between EHCI and companion controllers
05768918b Alan Stern 2013-03-28 28 * during EHCI probing and system resume.
6d19c009c Alan Stern 2010-02-12 29 */
6d19c009c Alan Stern 2010-02-12 30
05768918b Alan Stern 2013-03-28 @31 static DECLARE_RWSEM(companions_rwsem);
6d19c009c Alan Stern 2010-02-12 32

:::::: The code at line 31 was first introduced by commit
:::::: 05768918b9a122ce21bd55950df5054ff6c57f28 USB: improve port transitions when EHCI starts up

:::::: TO: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
:::::: CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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