Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <bbacb73a-6904-d196-ab4a-3e388bcab56c@metafoo.de>
Date:   Tue, 29 Nov 2022 10:23:04 -0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.5.0
Subject: Re: [PATCH 1/1] iio: imx8qxp-adc: fix irq flood when call
 imx8qxp_adc_read_raw()
Content-Language: en-US
To:     Frank Li <Frank.Li@nxp.com>, Cai Huoqing <cai.huoqing@linux.dev>,
        Haibo Chen <haibo.chen@nxp.com>,
        Jonathan Cameron <jic23@kernel.org>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        "open list:NXP i.MX 8QXP ADC DRIVER" <linux-iio@vger.kernel.org>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>,
        open list <linux-kernel@vger.kernel.org>
Cc:     imx@lists.linux.dev
References: <20221129164531.2164660-1-Frank.Li@nxp.com>
From:   Lars-Peter Clausen <lars@metafoo.de>
In-Reply-To: <20221129164531.2164660-1-Frank.Li@nxp.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 11/29/22 08:45, Frank Li wrote:
		       readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL));
> @@ -272,6 +275,10 @@ static irqreturn_t imx8qxp_adc_isr(int irq, void *dev_id)
>   	if (fifo_count)
>   		complete(&adc->completion);

Shouldn't the completion be triggered after the reading of the samples? 
otherwise you have a race condition on a multi-processor system.

>   
> +	for (i = 0; i < fifo_count; i++)
> +		adc->fifo[i] = FIELD_GET(IMX8QXP_ADC_RESFIFO_VAL_MASK,
> +				readl_relaxed(adc->regs + IMX8QXP_ADR_ADC_RESFIFO));
> +
>   	return IRQ_HANDLED;
>   }
>