2013-04-29 14:07:24

by Maxime Ripard

Subject: [PATCH] gpio: mxs: Use set and clear capabilities of the gpio controller

The current driver doesn't use the set and clear registers found on the
mxs gpio controller.

This leads the generic gpio controller to be using some internal value
to avoid looking up the value stored in the registers, making it behave
pretty much like a cache.

This raises some coherency problem when a gpio is not modified by the
gpio controller, while it can easily be fixed by using the set and clear
registers.

Signed-off-by: Maxime Ripard <[email protected]>
---
drivers/gpio/gpio-mxs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-mxs.c b/drivers/gpio/gpio-mxs.c
index 25000b0..f8e6af2 100644
--- a/drivers/gpio/gpio-mxs.c
+++ b/drivers/gpio/gpio-mxs.c
@@ -326,7 +326,8 @@ static int mxs_gpio_probe(struct platform_device *pdev)

err = bgpio_init(&port->bgc, &pdev->dev, 4,
port->base + PINCTRL_DIN(port),
- port->base + PINCTRL_DOUT(port), NULL,
+ port->base + PINCTRL_DOUT(port) + MXS_SET,
+ port->base + PINCTRL_DOUT(port) + MXS_CLR,
port->base + PINCTRL_DOE(port), NULL, 0);
if (err)
goto out_irqdesc_free;
--
1.8.1.2

2013-05-02 02:44:59

by Shawn Guo

Subject: Re: [PATCH] gpio: mxs: Use set and clear capabilities of the gpio controller

On Mon, Apr 29, 2013 at 04:07:18PM +0200, Maxime Ripard wrote:
> The current driver doesn't use the set and clear registers found on the
> mxs gpio controller.
>
> This leads the generic gpio controller to be using some internal value
> to avoid looking up the value stored in the registers, making it behave
> pretty much like a cache.
>
> This raises some coherency problem when a gpio is not modified by the
> gpio controller, while it can easily be fixed by using the set and clear
> registers.
>
> Signed-off-by: Maxime Ripard <[email protected]>

Acked-by: Shawn Guo <[email protected]>

> ---
> drivers/gpio/gpio-mxs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-mxs.c b/drivers/gpio/gpio-mxs.c
> index 25000b0..f8e6af2 100644
> --- a/drivers/gpio/gpio-mxs.c
> +++ b/drivers/gpio/gpio-mxs.c
> @@ -326,7 +326,8 @@ static int mxs_gpio_probe(struct platform_device *pdev)
>
> err = bgpio_init(&port->bgc, &pdev->dev, 4,
> port->base + PINCTRL_DIN(port),
> - port->base + PINCTRL_DOUT(port), NULL,
> + port->base + PINCTRL_DOUT(port) + MXS_SET,
> + port->base + PINCTRL_DOUT(port) + MXS_CLR,
> port->base + PINCTRL_DOE(port), NULL, 0);
> if (err)
> goto out_irqdesc_free;
> --
> 1.8.1.2
>

2013-05-16 15:38:11

by Maxime Ripard

Subject: Re: [PATCH] gpio: mxs: Use set and clear capabilities of the gpio controller

Hi Linus,

Le 02/05/2013 04:44, Shawn Guo a ?crit :
> On Mon, Apr 29, 2013 at 04:07:18PM +0200, Maxime Ripard wrote:
>> The current driver doesn't use the set and clear registers found on the
>> mxs gpio controller.
>>
>> This leads the generic gpio controller to be using some internal value
>> to avoid looking up the value stored in the registers, making it behave
>> pretty much like a cache.
>>
>> This raises some coherency problem when a gpio is not modified by the
>> gpio controller, while it can easily be fixed by using the set and clear
>> registers.
>>
>> Signed-off-by: Maxime Ripard <[email protected]>
>
> Acked-by: Shawn Guo <[email protected]>

Would you consider merging this patch?

Thanks,
Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

2013-05-20 18:15:45

by Linus Walleij

Subject: Re: [PATCH] gpio: mxs: Use set and clear capabilities of the gpio controller

On Mon, Apr 29, 2013 at 4:07 PM, Maxime Ripard
<[email protected]> wrote:

> The current driver doesn't use the set and clear registers found on the
> mxs gpio controller.
>
> This leads the generic gpio controller to be using some internal value
> to avoid looking up the value stored in the registers, making it behave
> pretty much like a cache.
>
> This raises some coherency problem when a gpio is not modified by the
> gpio controller, while it can easily be fixed by using the set and clear
> registers.
>
> Signed-off-by: Maxime Ripard <[email protected]>

Patch applied for rc-fixes with Shawns ACK.

Yours,
Linus Walleij