From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26F95C636CC for ; Tue, 31 Jan 2023 09:53:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230354AbjAaJw7 (ORCPT ); Tue, 31 Jan 2023 04:52:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230480AbjAaJw6 (ORCPT ); Tue, 31 Jan 2023 04:52:58 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B74BC61A3 for ; Tue, 31 Jan 2023 01:52:54 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D7736B81ACC for ; Tue, 31 Jan 2023 09:52:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D589C4339B; Tue, 31 Jan 2023 09:52:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675158771; bh=ONCKEiRJ8ulZkZQNhNE40vJNiYCF+KeUkPwZZ9amfTQ=; h=Subject:To:From:Date:From; b=0oCIhpSsGCf+R4rs8/WjUjR6TfHN2Zwiryo5YLAp2wll5UAEAf3vzkHvmtYlzHpCX bVdGKyb9q0yME/UQrlUHOO1tQP7Eh6UCVMsMQ2CVD9dwbjcPa5ihwBMID8lfZzIGCH hB+OmnswAE02jhAk46KCyvQYEN10sMI6GLvpvrIo= Subject: patch "iio: imx8qxp-adc: fix irq flood when call imx8qxp_adc_read_raw()" added to char-misc-linus To: Frank.Li@nxp.com, Jonathan.Cameron@huawei.com, Stable@vger.kernel.org, cai.huoqing@linux.dev, haibo.chen@nxp.com From: Date: Tue, 31 Jan 2023 10:52:38 +0100 Message-ID: <1675158758170107@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled iio: imx8qxp-adc: fix irq flood when call imx8qxp_adc_read_raw() to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 0fc3562a993c3dc41d1177b3983d9300d0db1d4d Mon Sep 17 00:00:00 2001 From: Frank Li Date: Thu, 1 Dec 2022 09:01:10 -0500 Subject: iio: imx8qxp-adc: fix irq flood when call imx8qxp_adc_read_raw() irq flood happen when run cat /sys/bus/iio/devices/iio:device0/in_voltage1_raw imx8qxp_adc_read_raw() { ... enable irq /* adc start */ writel(1, adc->regs + IMX8QXP_ADR_ADC_SWTRIG); ^^^^ trigger irq flood. wait_for_completion_interruptible_timeout(); readl(adc->regs + IMX8QXP_ADR_ADC_RESFIFO); ^^^^ clear irq here. ... } There is only FIFO watermark interrupt at this ADC controller. IRQ line will be assert until software read data from FIFO. So IRQ flood happen during wait_for_completion_interruptible_timeout(). Move FIFO read into irq handle to avoid irq flood. Fixes: 1e23dcaa1a9f ("iio: imx8qxp-adc: Add driver support for NXP IMX8QXP ADC") Cc: stable@vger.kernel.org Signed-off-by: Frank Li Reviewed-by: Cai Huoqing Reviewed-by: Haibo Chen Link: https://lore.kernel.org/r/20221201140110.2653501-1-Frank.Li@nxp.com Cc: Signed-off-by: Jonathan Cameron --- drivers/iio/adc/imx8qxp-adc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/imx8qxp-adc.c b/drivers/iio/adc/imx8qxp-adc.c index 36777b827165..f5a0fc9e64c5 100644 --- a/drivers/iio/adc/imx8qxp-adc.c +++ b/drivers/iio/adc/imx8qxp-adc.c @@ -86,6 +86,8 @@ #define IMX8QXP_ADC_TIMEOUT msecs_to_jiffies(100) +#define IMX8QXP_ADC_MAX_FIFO_SIZE 16 + struct imx8qxp_adc { struct device *dev; void __iomem *regs; @@ -95,6 +97,7 @@ struct imx8qxp_adc { /* Serialise ADC channel reads */ struct mutex lock; struct completion completion; + u32 fifo[IMX8QXP_ADC_MAX_FIFO_SIZE]; }; #define IMX8QXP_ADC_CHAN(_idx) { \ @@ -238,8 +241,7 @@ static int imx8qxp_adc_read_raw(struct iio_dev *indio_dev, return ret; } - *val = FIELD_GET(IMX8QXP_ADC_RESFIFO_VAL_MASK, - readl(adc->regs + IMX8QXP_ADR_ADC_RESFIFO)); + *val = adc->fifo[0]; mutex_unlock(&adc->lock); return IIO_VAL_INT; @@ -265,10 +267,15 @@ static irqreturn_t imx8qxp_adc_isr(int irq, void *dev_id) { struct imx8qxp_adc *adc = dev_id; u32 fifo_count; + int i; fifo_count = FIELD_GET(IMX8QXP_ADC_FCTRL_FCOUNT_MASK, readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL)); + 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)); + if (fifo_count) complete(&adc->completion); -- 2.39.1