Re: [PATCH] pinctrl: st: Fix Sparse error

Re: [PATCH] pinctrl: st: Fix Sparse error

[Patrice Chotard]

Hi Pramod

On 09/29/2014 03:48 PM, Pramod Gurav wrote:
> This change fixes below sparse error,
> drivers/pinctrl/pinctrl-st.c:1515:31: error: incompatible types for operation (>)
> drivers/pinctrl/pinctrl-st.c:1515:31:    left side has type void [noderef] <asn:2>*irqmux_base
> drivers/pinctrl/pinctrl-st.c:1515:31:    right side has type int
>
> The fix is done by removing a check on info->irqmux_base as
> info->irqmux_base has already been checked  for error when allocating it.
> Hence there is no need to redo the check.
>
> Cc: Maxime Coquelin <maxime.coquelin@st.com>
> Cc: Patrice Chotard <patrice.chotard@st.com>
> CC: Linus Walleij <linus.walleij@linaro.org>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
> ---
>   drivers/pinctrl/pinctrl-st.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
> index 5475374..ddeaeda 100644
> --- a/drivers/pinctrl/pinctrl-st.c
> +++ b/drivers/pinctrl/pinctrl-st.c
> @@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct st_pinctrl *info,
>   					     gpio_irq, st_gpio_irq_handler);
>   	}
>   
> -	if (info->irqmux_base > 0 || gpio_irq > 0) {
> +	if (gpio_irq > 0) {
>   		err = gpiochip_irqchip_add(&bank->gpio_chip, &st_gpio_irqchip,
>   					   0, handle_simple_irq,
>   					   IRQ_TYPE_LEVEL_LOW);


Acked-by: Patrice Chotard <patrice.chotard@st.com>

Thanks

[PATCH] pinctrl: st: Fix Sparse error

[Pramod Gurav]

This change fixes below sparse error,
drivers/pinctrl/pinctrl-st.c:1515:31: error: incompatible types for operation (>)
drivers/pinctrl/pinctrl-st.c:1515:31:    left side has type void [noderef] <asn:2>*irqmux_base
drivers/pinctrl/pinctrl-st.c:1515:31:    right side has type int

The fix is done by removing a check on info->irqmux_base as
info->irqmux_base has already been checked  for error when allocating it.
Hence there is no need to redo the check.

Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
CC: Linus Walleij <linus.walleij@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
---
 drivers/pinctrl/pinctrl-st.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
index 5475374..ddeaeda 100644
--- a/drivers/pinctrl/pinctrl-st.c
+++ b/drivers/pinctrl/pinctrl-st.c
@@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct st_pinctrl *info,
 					     gpio_irq, st_gpio_irq_handler);
 	}
 
-	if (info->irqmux_base > 0 || gpio_irq > 0) {
+	if (gpio_irq > 0) {
 		err = gpiochip_irqchip_add(&bank->gpio_chip, &st_gpio_irqchip,
 					   0, handle_simple_irq,
 					   IRQ_TYPE_LEVEL_LOW);
-- 
1.7.9.5

Re: [PATCH] pinctrl: st: Fix Sparse error

[Srinivas Kandagatla]

On 29/09/14 14:48, Pramod Gurav wrote:
> This change fixes below sparse error,
> drivers/pinctrl/pinctrl-st.c:1515:31: error: incompatible types for operation (>)
> drivers/pinctrl/pinctrl-st.c:1515:31:    left side has type void [noderef] <asn:2>*irqmux_base
> drivers/pinctrl/pinctrl-st.c:1515:31:    right side has type int
>
> The fix is done by removing a check on info->irqmux_base as
> info->irqmux_base has already been checked  for error when allocating it.
> Hence there is no need to redo the check.
>
> Cc: Maxime Coquelin <maxime.coquelin@st.com>
> Cc: Patrice Chotard <patrice.chotard@st.com>
> CC: Linus Walleij <linus.walleij@linaro.org>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
> ---
>   drivers/pinctrl/pinctrl-st.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
> index 5475374..ddeaeda 100644
> --- a/drivers/pinctrl/pinctrl-st.c
> +++ b/drivers/pinctrl/pinctrl-st.c
> @@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct st_pinctrl *info,
>   					     gpio_irq, st_gpio_irq_handler);
>   	}
>
> -	if (info->irqmux_base > 0 || gpio_irq > 0) {
> +	if (gpio_irq > 0) {
>   		err = gpiochip_irqchip_add(&bank->gpio_chip, &st_gpio_irqchip,
>   					   0, handle_simple_irq,
>   					   IRQ_TYPE_LEVEL_LOW);

This is not the correct fix. Please see why irqmux_base and gpio_irq are 
used in the driver.
You are breaking the logic here...

please read the below comment from the code.

	/**
	 * GPIO bank can have one of the two possible types of
	 * interrupt-wirings.
	 *
	 * First type is via irqmux, single interrupt is used by multiple
	 * gpio banks. This reduces number of overall interrupts numbers
	 * required. All these banks belong to a single pincontroller.
	 *		  _________
	 *		 |	   |----> [gpio-bank (n)    ]
	 *		 |	   |----> [gpio-bank (n + 1)]
	 *	[irqN]-- | irq-mux |----> [gpio-bank (n + 2)]
	 *		 |	   |----> [gpio-bank (...  )]
	 *		 |_________|----> [gpio-bank (n + 7)]
	 *
	 * Second type has a dedicated interrupt per each gpio bank.
	 *
	 *	[irqN]----> [gpio-bank (n)]
	 */


so irqmux_base is first type and gpio_irq is second type.
if you remove check for irqmux_base here you would end up NOT adding 
irqchip the gpiochip in first type so you break the existing logic here.


I think the correct fix is:

diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
index 5475374..4060c30 100644
--- a/drivers/pinctrl/pinctrl-st.c
+++ b/drivers/pinctrl/pinctrl-st.c
@@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct 
st_pinctrl *info,
                                              gpio_irq, 
st_gpio_irq_handler);
         }

-       if (info->irqmux_base > 0 || gpio_irq > 0) {
+       if (!IS_ERR(info->irqmux_base) || gpio_irq > 0) {
                 err = gpiochip_irqchip_add(&bank->gpio_chip, 
&st_gpio_irqchip,
                                            0, handle_simple_irq,
                                            IRQ_TYPE_LEVEL_LOW);


Thanks,
srini

Re: [PATCH] pinctrl: st: Fix Sparse error

[Pramod Gurav]

Hi Srini,

Thanks for review.

On Mon, Sep 29, 2014 at 8:16 PM, Srinivas Kandagatla
<srinivas.kandagatla@linaro.org> wrote:
> On 29/09/14 14:48, Pramod Gurav wrote:
>>
>> This change fixes below sparse error,
>> drivers/pinctrl/pinctrl-st.c:1515:31: error: incompatible types for
>> operation (>)
>> drivers/pinctrl/pinctrl-st.c:1515:31:    left side has type void [noderef]
>> <asn:2>*irqmux_base
>> drivers/pinctrl/pinctrl-st.c:1515:31:    right side has type int
>>
>> The fix is done by removing a check on info->irqmux_base as
>> info->irqmux_base has already been checked  for error when allocating it.
>> Hence there is no need to redo the check.
>>
>> Cc: Maxime Coquelin <maxime.coquelin@st.com>
>> Cc: Patrice Chotard <patrice.chotard@st.com>
>> CC: Linus Walleij <linus.walleij@linaro.org>
>> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
>> ---
>>   drivers/pinctrl/pinctrl-st.c |    2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
>> index 5475374..ddeaeda 100644
>> --- a/drivers/pinctrl/pinctrl-st.c
>> +++ b/drivers/pinctrl/pinctrl-st.c
>> @@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct
>> st_pinctrl *info,
>>                                              gpio_irq,
>> st_gpio_irq_handler);
>>         }
>>
>> -       if (info->irqmux_base > 0 || gpio_irq > 0) {
>> +       if (gpio_irq > 0) {
>>                 err = gpiochip_irqchip_add(&bank->gpio_chip,
>> &st_gpio_irqchip,
>>                                            0, handle_simple_irq,
>>                                            IRQ_TYPE_LEVEL_LOW);
>
>
> This is not the correct fix. Please see why irqmux_base and gpio_irq are
> used in the driver.
> You are breaking the logic here...
>
> please read the below comment from the code.
>
>         /**
>          * GPIO bank can have one of the two possible types of
>          * interrupt-wirings.
>          *
>          * First type is via irqmux, single interrupt is used by multiple
>          * gpio banks. This reduces number of overall interrupts numbers
>          * required. All these banks belong to a single pincontroller.
>          *                _________
>          *               |         |----> [gpio-bank (n)    ]
>          *               |         |----> [gpio-bank (n + 1)]
>          *      [irqN]-- | irq-mux |----> [gpio-bank (n + 2)]
>          *               |         |----> [gpio-bank (...  )]
>          *               |_________|----> [gpio-bank (n + 7)]
>          *
>          * Second type has a dedicated interrupt per each gpio bank.
>          *
>          *      [irqN]----> [gpio-bank (n)]
>          */
>
>
> so irqmux_base is first type and gpio_irq is second type.
> if you remove check for irqmux_base here you would end up NOT adding irqchip
> the gpiochip in first type so you break the existing logic here.
>
>
Thanks for this nice explanation.

> I think the correct fix is:
>
> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
> index 5475374..4060c30 100644
> --- a/drivers/pinctrl/pinctrl-st.c
> +++ b/drivers/pinctrl/pinctrl-st.c
> @@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct st_pinctrl
> *info,
>                                              gpio_irq, st_gpio_irq_handler);
>         }
>
> -       if (info->irqmux_base > 0 || gpio_irq > 0) {
> +       if (!IS_ERR(info->irqmux_base) || gpio_irq > 0) {
>                 err = gpiochip_irqchip_add(&bank->gpio_chip,
But if I am not wrong in function st_pctl_probe_dt, This is already done:

if (IS_ERR(info->irqmux_base))
            return PTR_ERR(info->irqmux_base);

That is the reason I thought there is no need to recheck the pointer
info->irqmux_base.
Am I misunderstanding something?
> &st_gpio_irqchip,
>                                            0, handle_simple_irq,
>                                            IRQ_TYPE_LEVEL_LOW);
>
>
> Thanks,
> srini
>
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-- 
Thanks and Regards
Pramod

Re: [PATCH] pinctrl: st: Fix Sparse error

[Daniel Thompson]

On 29/09/14 15:46, Srinivas Kandagatla wrote:
> On 29/09/14 14:48, Pramod Gurav wrote:
>> This change fixes below sparse error,
>> drivers/pinctrl/pinctrl-st.c:1515:31: error: incompatible types for
>> operation (>)
>> drivers/pinctrl/pinctrl-st.c:1515:31:    left side has type void
>> [noderef] <asn:2>*irqmux_base
>> drivers/pinctrl/pinctrl-st.c:1515:31:    right side has type int
>>
>> The fix is done by removing a check on info->irqmux_base as
>> info->irqmux_base has already been checked  for error when allocating it.
>> Hence there is no need to redo the check.
>>
>> Cc: Maxime Coquelin <maxime.coquelin@st.com>
>> Cc: Patrice Chotard <patrice.chotard@st.com>
>> CC: Linus Walleij <linus.walleij@linaro.org>
>> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
>> ---
>>   drivers/pinctrl/pinctrl-st.c |    2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
>> index 5475374..ddeaeda 100644
>> --- a/drivers/pinctrl/pinctrl-st.c
>> +++ b/drivers/pinctrl/pinctrl-st.c
>> @@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct
>> st_pinctrl *info,
>>                            gpio_irq, st_gpio_irq_handler);
>>       }
>>
>> -    if (info->irqmux_base > 0 || gpio_irq > 0) {
>> +    if (gpio_irq > 0) {
>>           err = gpiochip_irqchip_add(&bank->gpio_chip, &st_gpio_irqchip,
>>                          0, handle_simple_irq,
>>                          IRQ_TYPE_LEVEL_LOW);
> 
> This is not the correct fix. Please see why irqmux_base and gpio_irq are
> used in the driver.
> You are breaking the logic here...
> 
> please read the below comment from the code.
> 
>     /**
>      * GPIO bank can have one of the two possible types of
>      * interrupt-wirings.
>      *
>      * First type is via irqmux, single interrupt is used by multiple
>      * gpio banks. This reduces number of overall interrupts numbers
>      * required. All these banks belong to a single pincontroller.
>      *          _________
>      *         |       |----> [gpio-bank (n)    ]
>      *         |       |----> [gpio-bank (n + 1)]
>      *    [irqN]-- | irq-mux |----> [gpio-bank (n + 2)]
>      *         |       |----> [gpio-bank (...  )]
>      *         |_________|----> [gpio-bank (n + 7)]
>      *
>      * Second type has a dedicated interrupt per each gpio bank.
>      *
>      *    [irqN]----> [gpio-bank (n)]
>      */
> 
> 
> so irqmux_base is first type and gpio_irq is second type.
> if you remove check for irqmux_base here you would end up NOT adding
> irqchip the gpiochip in first type so you break the existing logic here.
> 
> 
> I think the correct fix is:
> 
> diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
> index 5475374..4060c30 100644
> --- a/drivers/pinctrl/pinctrl-st.c
> +++ b/drivers/pinctrl/pinctrl-st.c
> @@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct
> st_pinctrl *info,
>                                              gpio_irq,
> st_gpio_irq_handler);
>         }
> 
> -       if (info->irqmux_base > 0 || gpio_irq > 0) {
> +       if (!IS_ERR(info->irqmux_base) || gpio_irq > 0) {
>                 err = gpiochip_irqchip_add(&bank->gpio_chip,
> &st_gpio_irqchip,
>                                            0, handle_simple_irq,
>                                            IRQ_TYPE_LEVEL_LOW);

IS_ERR() should be irrelavent because the allocation code bombs out on
error. Shouldn't this just be a NULL pointer check?

  if(info->irqmux_base || gpio_irq > 0)


Daniel.

Re: [PATCH] pinctrl: st: Fix Sparse error

[Srinivas Kandagatla]

On 29/09/14 16:05, Pramod Gurav wrote:
>> >I think the correct fix is:
>> >
>> >diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
>> >index 5475374..4060c30 100644
>> >--- a/drivers/pinctrl/pinctrl-st.c
>> >+++ b/drivers/pinctrl/pinctrl-st.c
>> >@@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct st_pinctrl
>> >*info,
>> >                                              gpio_irq, st_gpio_irq_handler);
>> >         }
>> >
>> >-       if (info->irqmux_base > 0 || gpio_irq > 0) {
>> >+       if (!IS_ERR(info->irqmux_base) || gpio_irq > 0) {
>> >                 err = gpiochip_irqchip_add(&bank->gpio_chip,
> But if I am not wrong in function st_pctl_probe_dt, This is already done:
>
> if (IS_ERR(info->irqmux_base))
>              return PTR_ERR(info->irqmux_base);
>
> That is the reason I thought there is no need to recheck the pointer
> info->irqmux_base.
> Am I misunderstanding something?

Ok, we want to add the irqchip only when there is a valid irqmux_base or 
a valid gpio_irq per bank.

As st_gpiolib_register_bank() is used by both types of irq wirings and 
it does not know if irqmux or gpio irq is in use, so we need this 
explicit check. Also we want to make sure that atleast one type is valid 
before adding irqchip.

If you just check for only gpio_irq in this code, you would miss the 
case where irqmux is used.

As Dan pointed you could check if irqmux_base is valid and not remove it 
totally. Removing it will *break* the irqmux support as I explained.

thanks,
srini



>> >&st_gpio_irqchip,
>> >                                            0, handle_simple_irq,
>> >                                            IRQ_TYPE_LEVEL_LOW);
>> >
>> >

Re: [PATCH] pinctrl: st: Fix Sparse error

[Pramod Gurav]

On Mon, Sep 29, 2014 at 9:08 PM, Srinivas Kandagatla
<srinivas.kandagatla@linaro.org> wrote:
>
>
> On 29/09/14 16:05, Pramod Gurav wrote:
>>>
>>> >I think the correct fix is:
>>> >
>>> >diff --git a/drivers/pinctrl/pinctrl-st.c b/drivers/pinctrl/pinctrl-st.c
>>> >index 5475374..4060c30 100644
>>> >--- a/drivers/pinctrl/pinctrl-st.c
>>> >+++ b/drivers/pinctrl/pinctrl-st.c
>>> >@@ -1512,7 +1512,7 @@ static int st_gpiolib_register_bank(struct
>>> > st_pinctrl
>>> >*info,
>>> >                                              gpio_irq,
>>> > st_gpio_irq_handler);
>>> >         }
>>> >
>>> >-       if (info->irqmux_base > 0 || gpio_irq > 0) {
>>> >+       if (!IS_ERR(info->irqmux_base) || gpio_irq > 0) {
>>> >                 err = gpiochip_irqchip_add(&bank->gpio_chip,
>>
>> But if I am not wrong in function st_pctl_probe_dt, This is already done:
>>
>> if (IS_ERR(info->irqmux_base))
>>              return PTR_ERR(info->irqmux_base);
>>
>> That is the reason I thought there is no need to recheck the pointer
>> info->irqmux_base.
>> Am I misunderstanding something?
>
>
> Ok, we want to add the irqchip only when there is a valid irqmux_base or a
> valid gpio_irq per bank.
>
> As st_gpiolib_register_bank() is used by both types of irq wirings and it
> does not know if irqmux or gpio irq is in use, so we need this explicit
> check. Also we want to make sure that atleast one type is valid before
> adding irqchip.
>
> If you just check for only gpio_irq in this code, you would miss the case
> where irqmux is used.
>
> As Dan pointed you could check if irqmux_base is valid and not remove it
> totally. Removing it will *break* the irqmux support as I explained.
Thanks Srini, Will resend the patch.
>
> thanks,
> srini
>
>
>
>>> >&st_gpio_irqchip,
>>> >                                            0, handle_simple_irq,
>>> >                                            IRQ_TYPE_LEVEL_LOW);
>>> >
>>> >



-- 
Thanks and Regards
Pramod