linux-kernel - [PATCH] i2c: imx-lpi2c: change to PIO mode in system-wide suspend/resume progress

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Message-Id: <20251118071837.1419558-1-carlos.song@nxp.com>
Date: Tue, 18 Nov 2025 15:18:37 +0800
From: Carlos Song <carlos.song@....com>
To: aisheng.dong@....com,
	andi.shyti@...nel.org,
	shawnguo@...nel.org,
	s.hauer@...gutronix.de,
	kernel@...gutronix.de,
	festevam@...il.com,
	frank.li@....com
Cc: linux-i2c@...r.kernel.org,
	imx@...ts.linux.dev,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	Carlos Song <carlos.song@....com>
Subject: [PATCH] i2c: imx-lpi2c: change to PIO mode in system-wide suspend/resume progress

If a system-wide suspend or resume transition is in progress. LPI2C should
use PIO to transfer data not DMA to avoid issue caused by not ready DMA HW
resource.

Fixes: a09c8b3f9047 ("i2c: imx-lpi2c: add eDMA mode support for LPI2C")
Signed-off-by: Carlos Song <carlos.song@....com>
---
 drivers/i2c/busses/i2c-imx-lpi2c.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index 2a0962a0b441..5050e14a9919 100644
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -592,6 +592,13 @@ static bool is_use_dma(struct lpi2c_imx_struct *lpi2c_imx, struct i2c_msg *msg)
 	if (!lpi2c_imx->can_use_dma)
 		return false;
 
+	/*
+	 * When system is in suspend process. LPI2C should use PIO to transfer data to
+	 * avoid issue caused by not ready DMA HW resource.
+	 */
+	if (pm_suspend_in_progress())
+		return false;
+
 	/*
 	 * When the length of data is less than I2C_DMA_THRESHOLD,
 	 * cpu mode is used directly to avoid low performance.
-- 
2.34.1