Re: [PATCH 3/3] gpio-langwell: implement irq shutdown interface

[David Cohen <david.a.cohen@intel.com>]

On 12/19/2012 05:26 PM, Grant Likely wrote:
> On Tue, 18 Dec 2012 17:52:13 -0800, David Cohen <david.a.cohen@intel.com> wrote:
>> From: "Li, Ning" <ning.li@intel.com>
>>
>> Signed-off-by: David Cohen <david.a.cohen@intel.com>
>> Signed-off-by: Li, Ning <ning.li@intel.com>
> I could use some help interpreting this patch since it doesn't have any
> commit text describing why this patch is needed, nor does it have any
> comments in the code describing what it is doing.
>
> Having good commit text is important. Use it to tell me and future
> readers why this patch is important. What it does and how it was tested.
> Otherwise I end up trying to read your mind.
>
> (The patch does actually look fine to me, but it isn't okay to neglect
> a patch descirption on anything other than the most trivial of
> patches... and even then it triggers severe eyebrow raising)

Thanks for your reply. I'll add the description and resend it.

Br, David

>
> g.
>
>> ---
>>   drivers/gpio/gpio-langwell.c |   18 ++++++++++++++++++
>>   1 file changed, 18 insertions(+)
>>
>> diff --git a/drivers/gpio/gpio-langwell.c b/drivers/gpio/gpio-langwell.c
>> index dc534a9..c702d3d 100644
>> --- a/drivers/gpio/gpio-langwell.c
>> +++ b/drivers/gpio/gpio-langwell.c
>> @@ -219,12 +219,30 @@ static int lnw_irq_type(struct irq_data *d, unsigned type)
>>   
>>   static void lnw_irq_noop(struct irq_data *d) {}
>>   
>> +static void lnw_irq_shutdown(struct irq_data *d)
>> +{
>> +	struct lnw_gpio *lnw = irq_data_get_irq_chip_data(d);
>> +	u32 gpio = irqd_to_hwirq(d);
>> +	unsigned long flags;
>> +	u32 value;
>> +	void __iomem *grer = gpio_reg(&lnw->chip, gpio, GRER);
>> +	void __iomem *gfer = gpio_reg(&lnw->chip, gpio, GFER);
>> +
>> +	spin_lock_irqsave(&lnw->lock, flags);
>> +	value = readl(grer) & ~BIT(gpio % 32);
>> +	writel(value, grer);
>> +	value = readl(gfer) & ~BIT(gpio % 32);
>> +	writel(value, gfer);
>> +	spin_unlock_irqrestore(&lnw->lock, flags);
>> +};
>> +
>>   static struct irq_chip lnw_irqchip = {
>>   	.name		= "LNW-GPIO",
>>   	.irq_mask	= lnw_irq_noop,
>>   	.irq_unmask	= lnw_irq_noop,
>>   	.irq_set_type	= lnw_irq_type,
>>   	.irq_ack	= lnw_irq_noop,
>> +	.irq_shutdown	= lnw_irq_shutdown,
>>   };
>>   
>>   static DEFINE_PCI_DEVICE_TABLE(lnw_gpio_ids) = {   /* pin number */
>> -- 
>> 1.7.10.4
>>