Re: [PATCH v3 1/2] clocksource: Add Oxford Semiconductor RPS Dual Timer

From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Neil Armstrong <narmstrong@baylibre.com>,
	kbuild test robot <lkp@intel.com>
Cc: linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, tglx@linutronix.de,
	Ma Haijun <mahaijuns@gmail.com>
Subject: Re: [PATCH v3 1/2] clocksource: Add Oxford Semiconductor RPS Dual Timer
Date: Thu, 16 Jun 2016 16:14:19 +0200	[thread overview]
Message-ID: <5762B43B.9030104@linaro.org> (raw)
In-Reply-To: <5762AE08.50506@baylibre.com>

On 06/16/2016 03:47 PM, Neil Armstrong wrote:
> On 06/16/2016 03:33 PM, Daniel Lezcano wrote:
>> On 06/15/2016 05:35 PM, kbuild test robot wrote:
>>> Hi,
>>>
>>> [auto build test WARNING on tip/timers/core]
>>> [also build test WARNING on v4.7-rc3 next-20160615]
>>> [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/Neil-Armstrong/clocksource-Add-support-for-Oxford-Semiconductor-RPS-Dual-Timer/20160615-181650
>>> config: blackfin-allmodconfig (attached as .config)
>>> compiler: bfin-uclinux-gcc (GCC) 4.6.3
>>> reproduce:
>>>           wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
>>>           chmod +x ~/bin/make.cross
>>>           # save the attached .config to linux build tree
>>>           make.cross ARCH=blackfin
>>>
>>> All warnings (new ones prefixed by >>):
>>>
>>>>> drivers/clocksource/timer-oxnas-rps.c:50:0: warning: "TIMER_ENABLE" redefined [enabled by default]
>>>      arch/blackfin/mach-bf533/include/mach/defBF532.h:97:0: note: this is the location of the previous definition
>>>
>>> vim +/TIMER_ENABLE +50 drivers/clocksource/timer-oxnas-rps.c
>>>
>>>       34    /* TIMER1 used as tick
>>>       35     * TIMER2 used as clocksource
>>>       36     */
>>>       37
>>>       38    /* Registers definitions */
>>>       39
>>>       40    #define TIMER_LOAD_REG        0x0
>>>       41    #define TIMER_CURR_REG        0x4
>>>       42    #define TIMER_CTRL_REG        0x8
>>>       43    #define TIMER_CLRINT_REG    0xC
>>>       44
>>>       45    #define TIMER_BITS        24
>>>       46
>>>       47    #define TIMER_MAX_VAL        (BIT(TIMER_BITS) - 1)
>>>       48
>>>       49    #define TIMER_PERIODIC        BIT(6)
>>>     > 50    #define TIMER_ENABLE        BIT(7)
>>
>> It is already defined in the arch/blackfin/include dir.
>>
>
> Hi Daniel,
>
> This should never happen due to the blackfin headers.
> Actually the COMPILE_TEST option made these two happen.
>
> Should I push a v4 to keep COMPILE_TEST ?

The easier way would be:
	depends on !BLACKFIN

I will take care of cleaning up this macro name collision when moving 
the timer driver in drivers/clocksource (that's really in the future ...).

The idea is to have all the drivers with the COMPILE_TEST option set, so 
we can spot more issues at compile time earlier. This change reveals, of 
course, some errors we were not facing before and at least it has the 
benefit to enlighten some arch-shadowed drivers.

   -- Daniel

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