From: Jingoo Han <jg1.han@samsung.com>
To: 'Sachin Kamat' <sachin.kamat@linaro.org>,
'Thierry Reding' <thierry.reding@gmail.com>
Cc: linux-pwm@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
'Tomasz Figa' <tomasz.figa@gmail.com>,
'Jingoo Han' <jg1.han@samsung.com>
Subject: Re: [PATCH 1/1] pwm: samsung: Fix kernel warning while unexporting a channel
Date: Tue, 29 Oct 2013 14:04:48 +0900 [thread overview]
Message-ID: <002301ced464$6448bdf0$2cda39d0$%han@samsung.com> (raw)
In-Reply-To: <1383022663-22315-1-git-send-email-sachin.kamat@linaro.org>
On Tuesday, October 29, 2013 1:58 PM, Sachin Kamat wrote:
>
> PWM channel data was set to NULL before freeing it. This caused the
> following kernel warning while unexporting the channel. Set the channel
> data to NULL after freeing it.
>
> [ 70.495000] WARNING: CPU: 0 PID: 1 at drivers/base/devres.c:805 pwm_put+0x48/0x80()
> [ 70.505000] Modules linked in:
> [ 70.505000] CPU: 0 PID: 1 Comm: sh Not tainted 3.12.0-rc6-next-20131024-00012-gd4aec04-dirty #58
> [ 70.515000] [<c0014ddc>] (unwind_backtrace+0x0/0xf4) from [<c0011784>] (show_stack+0x10/0x14)
> [ 70.525000] [<c0011784>] (show_stack+0x10/0x14) from [<c03a3cbc>] (dump_stack+0x7c/0xb0)
> [ 70.530000] [<c03a3cbc>] (dump_stack+0x7c/0xb0) from [<c001de68>] (warn_slowpath_common+0x6c/0x88)
> [ 70.540000] [<c001de68>] (warn_slowpath_common+0x6c/0x88) from [<c001df20>]
> (warn_slowpath_null+0x1c/0x24)
> [ 70.550000] [<c001df20>] (warn_slowpath_null+0x1c/0x24) from [<c01d1af8>] (pwm_put+0x48/0x80)
> [ 70.560000] [<c01d1af8>] (pwm_put+0x48/0x80) from [<c01d21c8>] (pwm_unexport_store+0x94/0xac)
> [ 70.565000] [<c01d21c8>] (pwm_unexport_store+0x94/0xac) from [<c010991c>]
> (sysfs_write_file+0x148/0x1d8)
> [ 70.575000] [<c010991c>] (sysfs_write_file+0x148/0x1d8) from [<c00b2a80>] (vfs_write+0xb4/0x1a0)
> [ 70.585000] [<c00b2a80>] (vfs_write+0xb4/0x1a0) from [<c00b3068>] (SyS_write+0x3c/0x78)
> [ 70.595000] [<c00b3068>] (SyS_write+0x3c/0x78) from [<c000e2e0>] (ret_fast_syscall+0x0/0x30)
>
> Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Best regards,
Jingoo Han
> ---
> drivers/pwm/pwm-samsung.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pwm/pwm-samsung.c b/drivers/pwm/pwm-samsung.c
> index b2c54c8..6d23eb3 100644
> --- a/drivers/pwm/pwm-samsung.c
> +++ b/drivers/pwm/pwm-samsung.c
> @@ -226,8 +226,8 @@ static int pwm_samsung_request(struct pwm_chip *chip, struct pwm_device *pwm)
>
> static void pwm_samsung_free(struct pwm_chip *chip, struct pwm_device *pwm)
> {
> - pwm_set_chip_data(pwm, NULL);
> devm_kfree(chip->dev, pwm_get_chip_data(pwm));
> + pwm_set_chip_data(pwm, NULL);
> }
>
> static int pwm_samsung_enable(struct pwm_chip *chip, struct pwm_device *pwm)
> --
> 1.7.9.5
next prev parent reply other threads:[~2013-10-29 5:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-29 4:57 [PATCH 1/1] pwm: samsung: Fix kernel warning while unexporting a channel Sachin Kamat
2013-10-29 5:04 ` Jingoo Han [this message]
2013-11-01 10:20 ` Thierry Reding
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