linux-kernel - [PATCH v3 2/2] can: flexcan: disable transceiver during system PM

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Message-Id: <20250314110145.899179-2-haibo.chen@nxp.com>
Date: Fri, 14 Mar 2025 19:01:45 +0800
From: haibo.chen@....com
To: mkl@...gutronix.de,
	mailhol.vincent@...adoo.fr
Cc: haibo.chen@....com,
	ciprianmarian.costea@....nxp.com,
	u.kleine-koenig@...libre.com,
	fabio.estevam@....com,
	festevam@...il.com,
	linux-can@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	stable@...r.kernel.org,
	imx@...ts.linux.dev,
	han.xu@....com
Subject: [PATCH v3 2/2] can: flexcan: disable transceiver during system PM

From: Haibo Chen <haibo.chen@....com>

During system PM, if no wakeup requirement, disable transceiver to
save power.

Fixes: 4de349e786a3 ("can: flexcan: fix resume function")
Cc: stable@...r.kernel.org
Reviewed-by: Frank Li <frank.li@....com>
Signed-off-by: Haibo Chen <haibo.chen@....com>
---
Changes for V3:
 N/A

Changes for V2:
 - add return check for flexcan_transceiver_disable
 - disable transceiver if flexcan_chip_start() failed

---
 drivers/net/can/flexcan/flexcan-core.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index d4d342d8f490..491f9548c7ae 100644
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -2292,6 +2292,9 @@ static int __maybe_unused flexcan_suspend(struct device *device)
 				return err;
 
 			flexcan_chip_interrupts_disable(dev);
+			err = flexcan_transceiver_disable(priv);
+			if (err)
+				return err;
 
 			err = pinctrl_pm_select_sleep_state(device);
 			if (err)
@@ -2324,10 +2327,16 @@ static int __maybe_unused flexcan_resume(struct device *device)
 			if (err)
 				return err;
 
-			err = flexcan_chip_start(dev);
+			err = flexcan_transceiver_enable(priv);
 			if (err)
 				return err;
 
+			err = flexcan_chip_start(dev);
+			if (err) {
+				flexcan_transceiver_disable(priv);
+				return err;
+			}
+
 			flexcan_chip_interrupts_enable(dev);
 		}
 		priv->can.state = CAN_STATE_ERROR_ACTIVE;
-- 
2.34.1