Re: [PATCH v3] drivers: cpufreq: Fix sysfs duplicate filename creation for platform-device

[Viresh Kumar <viresh.kumar@linaro.org>]

On 21-09-17, 19:09, sunil.m@techveda.org wrote:
> From: Suniel Mahesh <sunil.m@techveda.org>
> 
> ti-cpufreq and cpufreq-dt-platdev drivers are registering platform-device
> with same name "cpufreq-dt" using platform_device_register_*() routines.
> This is leading to build warnings appended below.
> 
> Providing hardware information to OPP framework along with the platform-
> device creation should be done by ti-cpufreq driver before cpufreq-dt
> driver comes into place.
> 
> This patch add's TI am33xx, am43 and dra7 platforms (which use opp-v2
> property) to the blacklist of devices in cpufreq-dt-platform driver to
> avoid creating platform-device twice and remove build warnings.
> 
> [    2.370167] ------------[ cut here ]------------
> [    2.375087] WARNING: CPU: 0 PID: 1 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x58/0x78
> [    2.383112] sysfs: cannot create duplicate filename '/devices/platform/cpufreq-dt'
> [    2.391219] Modules linked in:
> [    2.394506] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.13.0-next-20170912 #1
> [    2.402006] Hardware name: Generic AM33XX (Flattened Device Tree)
> [    2.408437] [<c0110a28>] (unwind_backtrace) from [<c010ca84>] (show_stack+0x10/0x14)
> [    2.416568] [<c010ca84>] (show_stack) from [<c0827d64>] (dump_stack+0xac/0xe0)
> [    2.424165] [<c0827d64>] (dump_stack) from [<c0137470>] (__warn+0xd8/0x104)
> [    2.431488] [<c0137470>] (__warn) from [<c01374d0>] (warn_slowpath_fmt+0x34/0x44)
> [    2.439351] [<c01374d0>] (warn_slowpath_fmt) from [<c03459d0>] (sysfs_warn_dup+0x58/0x78)
> [    2.447938] [<c03459d0>] (sysfs_warn_dup) from [<c0345ab8>] (sysfs_create_dir_ns+0x80/0x98)
> [    2.456719] [<c0345ab8>] (sysfs_create_dir_ns) from [<c082c554>] (kobject_add_internal+0x9c/0x2d4)
> [    2.466124] [<c082c554>] (kobject_add_internal) from [<c082c7d8>] (kobject_add+0x4c/0x9c)
> [    2.474712] [<c082c7d8>] (kobject_add) from [<c05803e4>] (device_add+0xcc/0x57c)
> [    2.482489] [<c05803e4>] (device_add) from [<c0584b74>] (platform_device_add+0x100/0x220)
> [    2.491085] [<c0584b74>] (platform_device_add) from [<c05855a8>] (platform_device_register_full+0xf4/0x118)
> [    2.501305] [<c05855a8>] (platform_device_register_full) from [<c067023c>] (ti_cpufreq_init+0x150/0x22c)
> [    2.511253] [<c067023c>] (ti_cpufreq_init) from [<c0101df4>] (do_one_initcall+0x3c/0x170)
> [    2.519838] [<c0101df4>] (do_one_initcall) from [<c0c00eb4>] (kernel_init_freeable+0x1fc/0x2c4)
> [    2.528974] [<c0c00eb4>] (kernel_init_freeable) from [<c083bcac>] (kernel_init+0x8/0x110)
> [    2.537565] [<c083bcac>] (kernel_init) from [<c0107d18>] (ret_from_fork+0x14/0x3c)
> [    2.545981] ---[ end trace 2fc00e213c13ab20 ]---
> [    2.551051] ------------[ cut here ]------------
> [    2.555931] WARNING: CPU: 0 PID: 1 at lib/kobject.c:240 kobject_add_internal+0x254/0x2d4
> [    2.564578] kobject_add_internal failed for cpufreq-dt with -EEXIST, don't try to register
> things with the same name in the same directory.
> [    2.577977] Modules linked in:
> [    2.581261] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W       4.13.0-next-20170912 #1
> [    2.590013] Hardware name: Generic AM33XX (Flattened Device Tree)
> [    2.596437] [<c0110a28>] (unwind_backtrace) from [<c010ca84>] (show_stack+0x10/0x14)
> [    2.604573] [<c010ca84>] (show_stack) from [<c0827d64>] (dump_stack+0xac/0xe0)
> [    2.612172] [<c0827d64>] (dump_stack) from [<c0137470>] (__warn+0xd8/0x104)
> [    2.619494] [<c0137470>] (__warn) from [<c01374d0>] (warn_slowpath_fmt+0x34/0x44)
> [    2.627362] [<c01374d0>] (warn_slowpath_fmt) from [<c082c70c>] (kobject_add_internal+0x254/0x2d4)
> [    2.636666] [<c082c70c>] (kobject_add_internal) from [<c082c7d8>] (kobject_add+0x4c/0x9c)
> [    2.645255] [<c082c7d8>] (kobject_add) from [<c05803e4>] (device_add+0xcc/0x57c)
> [    2.653027] [<c05803e4>] (device_add) from [<c0584b74>] (platform_device_add+0x100/0x220)
> [    2.661615] [<c0584b74>] (platform_device_add) from [<c05855a8>] (platform_device_register_full+0xf4/0x118)
> [    2.671833] [<c05855a8>] (platform_device_register_full) from [<c067023c>] (ti_cpufreq_init+0x150/0x22c)
> [    2.681779] [<c067023c>] (ti_cpufreq_init) from [<c0101df4>] (do_one_initcall+0x3c/0x170)
> [    2.690377] [<c0101df4>] (do_one_initcall) from [<c0c00eb4>] (kernel_init_freeable+0x1fc/0x2c4)
> [    2.699510] [<c0c00eb4>] (kernel_init_freeable) from [<c083bcac>] (kernel_init+0x8/0x110)
> [    2.708106] [<c083bcac>] (kernel_init) from [<c0107d18>] (ret_from_fork+0x14/0x3c)
> [    2.716217] ---[ end trace 2fc00e213c13ab21 ]---
> 
> Fixes: edeec420de24 ("cpufreq: dt-cpufreq: platdev Automatically create device with OPP v2")
> Signed-off-by: Suniel Mahesh <sunil.m@techveda.org>
> ---
> Changes for v3:
> - Added ti,am43 and ti,dra7 platforms to the blacklist as requested
>   by Dave Gerlach.
> - Patch Description modified a bit.
> - Patch was rebased on pm/linux-next as suggested by Viresh, compile
>   tested and built(ARCH=arm) on both linux/pm-next and next-20170918.
> ---
> Changes for v2:
> - The approach (as a result patch decsription) was changed as per
>   inputs given by Viresh.
> - Patch was compile tested and built(ARCH=arm) on next-20170918.
> ---
> Note:
> - Patch was hardware tested on AM335x SOC based board.
> - cpufreq-dt driver got probed and entries related to Dynamic Voltage
>   and Frequency scaling were created in
>   sysfs @ sys/devices/system/cpu/cpu0/cpufreq.
> - No build/run-time issues reported.
> ---
>  drivers/cpufreq/cpufreq-dt-platdev.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/cpufreq/cpufreq-dt-platdev.c b/drivers/cpufreq/cpufreq-dt-platdev.c
> index 430edad..a753c50 100644
> --- a/drivers/cpufreq/cpufreq-dt-platdev.c
> +++ b/drivers/cpufreq/cpufreq-dt-platdev.c
> @@ -118,6 +118,10 @@
>  
>  	{ .compatible = "sigma,tango4", },
>  
> +	{ .compatible = "ti,am33xx", },
> +	{ .compatible = "ti,am43", },
> +	{ .compatible = "ti,dra7", },
> +
>  	{ }
>  };

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

-- 
viresh