linux-kernel - [PATCH v2 09/11] can: tcan4x5x: Fix use of register error status mask

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Message-Id: <20221206115728.1056014-10-msp@baylibre.com>
Date:   Tue,  6 Dec 2022 12:57:26 +0100
From:   Markus Schneider-Pargmann <msp@...libre.com>
To:     Chandrasekar Ramakrishnan <rcsekar@...sung.com>,
        Marc Kleine-Budde <mkl@...gutronix.de>,
        Wolfgang Grandegger <wg@...ndegger.com>
Cc:     linux-can@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Markus Schneider-Pargmann <msp@...libre.com>
Subject: [PATCH v2 09/11] can: tcan4x5x: Fix use of register error status mask

TCAN4X5X_ERROR_STATUS is not a status register that needs clearing
during interrupt handling. Instead this is a masking register that masks
error interrupts. Writing TCAN4X5X_CLEAR_ALL_INT to this register
effectively masks everything.

Rename the register and mask all error interrupts only once by writing
to the register in tcan4x5x_init.

Fixes: 5443c226ba91 ("can: tcan4x5x: Add tcan4x5x driver to the kernel")
Signed-off-by: Markus Schneider-Pargmann <msp@...libre.com>
---

Notes:
    v2:
     - Add fixes tag

 drivers/net/can/m_can/tcan4x5x-core.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_can/tcan4x5x-core.c
index 1fec394b3517..efa2381bf85b 100644
--- a/drivers/net/can/m_can/tcan4x5x-core.c
+++ b/drivers/net/can/m_can/tcan4x5x-core.c
@@ -10,7 +10,7 @@
 #define TCAN4X5X_DEV_ID1 0x04
 #define TCAN4X5X_REV 0x08
 #define TCAN4X5X_STATUS 0x0C
-#define TCAN4X5X_ERROR_STATUS 0x10
+#define TCAN4X5X_ERROR_STATUS_MASK 0x10
 #define TCAN4X5X_CONTROL 0x14
 
 #define TCAN4X5X_CONFIG 0x800
@@ -204,12 +204,7 @@ static int tcan4x5x_clear_interrupts(struct m_can_classdev *cdev)
 	if (ret)
 		return ret;
 
-	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
-				      TCAN4X5X_CLEAR_ALL_INT);
-	if (ret)
-		return ret;
-
-	return tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS,
+	return tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
 				       TCAN4X5X_CLEAR_ALL_INT);
 }
 
@@ -229,6 +224,11 @@ static int tcan4x5x_init(struct m_can_classdev *cdev)
 	if (ret)
 		return ret;
 
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS_MASK,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
 	/* Zero out the MCAN buffers */
 	ret = m_can_init_ram(cdev);
 	if (ret)
-- 
2.38.1