Re: [PATCH] mfd/stmpe: Add support for no-interrupt config

[Viresh Kumar <viresh.kumar@st.com>]

On 1/24/2012 3:48 PM, Linus WALLEIJ wrote:
> From: Chris Blair <chris.blair@stericsson.com>
> 
> Adds support for boards which have an STMPE device without the
> interrupt pin connected.
> 
> Cc: Viresh Kumar <viresh.kumar@st.com>
> Signed-off-by: Chris Blair <chris.blair@stericsson.com>
> Tested-by: Michel Jaouen <michel.jaouen@stericsson.com>
> Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/mfd/stmpe.c       |   72 +++++++++++++++++++++++++--------------------
>  include/linux/mfd/stmpe.h |    2 +
>  2 files changed, 42 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/mfd/stmpe.c b/drivers/mfd/stmpe.c

> @@ -988,7 +990,7 @@ int __devinit stmpe_probe(struct stmpe_client_info *ci, int partnum)
>  	if (ci->init)
>  		ci->init(stmpe);
>  
> -	if (pdata->irq_over_gpio) {
> +	if (!pdata->no_irq && pdata->irq_over_gpio) {
>  		ret = gpio_request_one(pdata->irq_gpio, GPIOF_DIR_IN, "stmpe");
>  		if (ret) {
>  			dev_err(stmpe->dev, "failed to request IRQ GPIO: %d\n",

[I will add the actual code present here after this change to describe the concern]

	if (!pdata->no_irq && pdata->irq_over_gpio) {
		ret = gpio_request_one(pdata->irq_gpio, GPIOF_DIR_IN, "stmpe");
		if (ret) {
			dev_err(stmpe->dev, "failed to request IRQ GPIO: %d\n",
					ret);
			goto out_free;
		}

		stmpe->irq = gpio_to_irq(pdata->irq_gpio);
	} else {
		stmpe->irq = ci->irq;
	}

Actually you want neither of them to work for no_irq case, if and else.
But with this code, if you pass no_irq = true, then else part will get called.

> @@ -1005,15 +1007,21 @@ int __devinit stmpe_probe(struct stmpe_client_info *ci, int partnum)
>  	if (ret)
>  		goto free_gpio;
>  
> -	ret = stmpe_irq_init(stmpe);
> -	if (ret)
> -		goto free_gpio;
> +	if (pdata->no_irq) {
> +		dev_info(stmpe->dev,
> +			"board config says IRQs are not supported\n");
> +	} else {
> +		ret = stmpe_irq_init(stmpe);
> +		if (ret)
> +			goto free_gpio;
>  

There are few more cases to handle in error part of probe and remove, where
following routines are called.

	free_irq(stmpe->irq, stmpe);
	stmpe_irq_remove(stmpe);
	if (pdata->irq_over_gpio)
		gpio_free(pdata->irq_gpio);

-- 
viresh