Re: [PATCH RFC net 1/2] nfc: nxp-nci: Fix i2c read on ThinkPad hardware

Re: [PATCH RFC net 1/2] nfc: nxp-nci: Fix i2c read on ThinkPad hardware

[Krzysztof Kozlowski]

On 07/06/2023 19:00, Marco Giorgi wrote:
> Add the IRQ GPIO configuration.

Why? Please include reasons in commit msg. What you are doing is quite
easy to see.

> 
> Signed-off-by: Marco Giorgi <giorgi.marco.96@disroot.org>
> ---
>  drivers/nfc/nxp-nci/i2c.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/nfc/nxp-nci/i2c.c b/drivers/nfc/nxp-nci/i2c.c
> index d4c299be7949..4ba26a958258 100644
> --- a/drivers/nfc/nxp-nci/i2c.c
> +++ b/drivers/nfc/nxp-nci/i2c.c
> @@ -35,6 +35,7 @@ struct nxp_nci_i2c_phy {
>  
>  	struct gpio_desc *gpiod_en;
>  	struct gpio_desc *gpiod_fw;
> +	struct gpio_desc *gpiod_irq;
>  
>  	int hard_fault; /*
>  			 * < 0 if hardware error occurred (e.g. i2c err)
> @@ -254,10 +255,12 @@ static irqreturn_t nxp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
>  	return IRQ_NONE;
>  }
>  
> +static const struct acpi_gpio_params irq_gpios = { 0, 0, false };
>  static const struct acpi_gpio_params firmware_gpios = { 1, 0, false };
>  static const struct acpi_gpio_params enable_gpios = { 2, 0, false };
>  
>  static const struct acpi_gpio_mapping acpi_nxp_nci_gpios[] = {
> +	{ "irq-gpios", &irq_gpios, 1 },
>  	{ "enable-gpios", &enable_gpios, 1 },
>  	{ "firmware-gpios", &firmware_gpios, 1 },
>  	{ }
> @@ -286,6 +289,12 @@ static int nxp_nci_i2c_probe(struct i2c_client *client)
>  	if (r)
>  		dev_dbg(dev, "Unable to add GPIO mapping table\n");
>  
> +	phy->gpiod_irq = devm_gpiod_get(dev, "irq", GPIOD_IN);

Bindings do not allow it. Please update bindings... or not, because they
clearly state that interrupts are already there.

You need to explain what is this.



Best regards,
Krzysztof

Re: [PATCH RFC net 1/2] nfc: nxp-nci: Fix i2c read on ThinkPad hardware

[Krzysztof Kozlowski]

On 11/06/2023 18:25, Marco Giorgi wrote:
> Hi Krzysztof,
> 
> On Wed, 7 Jun 2023 19:45:25 +0200
> Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:
> 
>> On 07/06/2023 19:00, Marco Giorgi wrote:
>>> Add the IRQ GPIO configuration.  
>>
>> Why? Please include reasons in commit msg. What you are doing is quite
>> easy to see.
> 
> This is my fault, I only put the patch reason in patch [0/2].
> 
> Basically, I found out that the mainline driver is not working on my
> machine (Lenovo ThinkPad T590).
> 
> I suspect that the I2C read IRQ is somehow misconfigured, and it
> triggers even when the NFC chip is not ready to be read, resulting in
> an error.

Isn't this then a problem of your I2C controller?

> 
> In this patch [1/2], I'm adding the "IRQ" GPIO to the driver so its
> value can be directly read from the IRQ thread.

What is IRQ GPIO? If this is interrupt line, you are not handling it
correctly. This is quite surprising code.

> 
> In patch [2/2], I'm safely returning from the IRQ thread when the IRQ
> GPIO is not active.
> 


Best regards,
Krzysztof

Re: [PATCH RFC net 2/2] nfc: nxp-nci: Fix i2c read on ThinkPad hardware

[Krzysztof Kozlowski]

On 07/06/2023 19:00, Marco Giorgi wrote:
> Read IRQ GPIO value and exit from IRQ if the device is not ready.

Why? What problem are you solving?

Why IRQ GPIO - whatever it is - means device is not ready for I2C transfer?

> 
> Signed-off-by: Marco Giorgi <giorgi.marco.96@disroot.org>
> ---
>  drivers/nfc/nxp-nci/i2c.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)

Best regards,
Krzysztof