From: rmallon@gmail•com (Ryan Mallon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3 06/10] pwm: Add NVIDIA Tegra SoC support
Date: Thu, 23 Feb 2012 20:25:42 +1100 [thread overview]
Message-ID: <4F460616.3080400@gmail.com> (raw)
In-Reply-To: <20120223081459.GD8621@avionic-0098.mockup.avionic-design.de>
On 23/02/12 19:14, Thierry Reding wrote:
> * Ryan Mallon wrote:
>> On 23/02/12 02:17, Thierry Reding wrote:
>>
>>> This commit adds a generic PWM framework driver for the PWFM controller
>>> found on NVIDIA Tegra SoCs. The driver is based on code from the
>>> Chromium kernel tree and was originally written by Gary King (NVIDIA)
>>> and later modified by Simon Que (Chromium).
>>>
>>> Signed-off-by: Thierry Reding <thierry.reding@avionic-design•de>
>>> ---
>>
>> <snip>
>>
>>> +
>>> + pwm->chip.dev = &pdev->dev;
>>> + pwm->chip.ops = &tegra_pwm_ops;
>>> + pwm->chip.base = -1;
>>> + pwm->chip.npwm = NUM_PWM;
>>
>>> +
>>> + ret = pwmchip_add(&pwm->chip);
>>
>>
>> If a driver fails to initialise the pwm_chip structure correctly it can
>> cause problems in the pwm core. For example, if the dev field doesn't
>> get set, then you will get an oops if you try to cat the pwm debugfs file.
>>
>> pwmchip_add should probably verify that the initialisation of the
>> pwm_chip structure is sane to avoid problems like this.
>
> Absolutely. What would be the best response to an invalid struct pwm_chip? I
> suppose at least returning -EINVAL, perhaps complemented with WARN_ON?
Just returning -EINVAL should be okay. I don't think you need a WARN_ON,
since failing to register the hardware should be enough of a reason for
a user to report a problem.
~Ryan
next prev parent reply other threads:[~2012-02-23 9:25 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-22 15:17 [PATCH v3 00/10] Add PWM framework and device tree support Thierry Reding
2012-02-22 15:17 ` [PATCH v3 01/10] PWM: add pwm framework support Thierry Reding
2012-02-22 15:17 ` [PATCH v3 02/10] pwm: Allow chips to support multiple PWMs Thierry Reding
2012-02-22 16:34 ` Arnd Bergmann
2012-02-23 8:12 ` Thierry Reding
2012-02-23 14:07 ` Arnd Bergmann
2012-02-23 16:04 ` Thierry Reding
2012-03-03 19:32 ` Thierry Reding
2012-03-06 15:38 ` Arnd Bergmann
2012-03-06 19:17 ` Thierry Reding
2012-02-22 15:17 ` [PATCH v3 03/10] of: Add PWM support Thierry Reding
2012-02-22 16:15 ` Arnd Bergmann
2012-02-23 7:55 ` Thierry Reding
2012-02-23 14:03 ` Arnd Bergmann
2012-02-24 6:47 ` Thierry Reding
2012-02-24 16:58 ` Arnd Bergmann
2012-02-25 12:33 ` Sascha Hauer
2012-02-25 23:08 ` Ryan Mallon
2012-02-22 15:17 ` [PATCH v3 04/10] arm/tegra: Fix PWM clock programming Thierry Reding
2012-02-28 21:01 ` Stephen Warren
2012-03-03 22:47 ` Thierry Reding
2012-03-05 17:33 ` Stephen Warren
2012-02-22 15:17 ` [PATCH v3 05/10] arm/tegra: Provide clock for only one PWM controller Thierry Reding
2012-02-22 15:17 ` [PATCH v3 06/10] pwm: Add NVIDIA Tegra SoC support Thierry Reding
2012-02-23 1:47 ` Ryan Mallon
2012-02-23 8:14 ` Thierry Reding
2012-02-23 9:25 ` Ryan Mallon [this message]
2012-02-24 6:48 ` Thierry Reding
2012-02-28 21:14 ` Stephen Warren
2012-03-03 22:42 ` Thierry Reding
2012-03-05 3:39 ` Olof Johansson
2012-03-05 7:00 ` Thierry Reding
2012-02-22 15:17 ` [PATCH v3 07/10] arm/tegra: Add PWFM controller device tree probing Thierry Reding
2012-02-28 21:20 ` Stephen Warren
2012-03-03 22:54 ` Thierry Reding
2012-03-04 20:39 ` Arnd Bergmann
2012-03-05 17:51 ` Stephen Warren
2012-03-05 18:15 ` Thierry Reding
2012-03-05 18:39 ` Stephen Warren
2012-02-22 15:17 ` [PATCH v3 08/10] pwm: Add Blackfin support Thierry Reding
2012-02-22 15:17 ` [PATCH v3 09/10] pwm: Add PXA support Thierry Reding
2012-02-22 15:40 ` Arnd Bergmann
2012-02-23 6:10 ` Thierry Reding
2012-02-22 15:17 ` [PATCH v3 10/10] pwm-backlight: Add rudimentary device tree support Thierry Reding
2012-02-22 16:02 ` [PATCH v3 00/10] Add PWM framework and " Arnd Bergmann
2012-02-23 7:29 ` Thierry Reding
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