linux-kernel - Re: [PATCH 2/5] i2c: imx-lpi2c: add IRQF_NO

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Message-ID: <6bc3f830-13dc-4df1-ad41-6228976c0dcd@gmx.net>
Date: Thu, 29 Aug 2024 12:52:32 +0200
From: Stefan Wahren <wahrenst@....net>
To: carlos.song@....com, aisheng.dong@....com, andi.shyti@...nel.org,
 shawnguo@...nel.org, s.hauer@...gutronix.de, kernel@...gutronix.de,
 festevam@...il.com
Cc: linux-i2c@...r.kernel.org, imx@...ts.linux.dev,
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/5] i2c: imx-lpi2c: add IRQF_NO_SUSPEND IRQ flag

Hi Carlos,

Am 29.08.24 um 11:37 schrieb carlos.song@....com:
> From: Carlos Song <carlos.song@....com>
>
> Set IRQF_NO_SUSPEND flag when request_irq(). Some devices such
> as extend GPIO will need i2c transfer during the entire system
> suspend and resume period so keep it enabled.
do you mean GPIO expander which are connected to I2C?

Do the mentioned expander have a dedicated IRQ line or does the host
needs to poll I2C?

Best regards

>
> Signed-off-by: Carlos Song <carlos.song@....com>
> Signed-off-by: Frank Li <Frank.Li@....com>
> ---
>   drivers/i2c/busses/i2c-imx-lpi2c.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
> index c8f3dadfb36e..23f83f10d5f6 100644
> --- a/drivers/i2c/busses/i2c-imx-lpi2c.c
> +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
> @@ -1309,7 +1309,7 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
>   	if (ret)
>   		lpi2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ;
>
> -	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, 0,
> +	ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, IRQF_NO_SUSPEND,
>   			       pdev->name, lpi2c_imx);
>   	if (ret)
>   		return dev_err_probe(&pdev->dev, ret, "can't claim irq %d\n", irq);