can: tcan4x5x: Fix use of register error status mask

[ Upstream commit 67727a1 ]

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: 5443c22 ("can: tcan4x5x: Add tcan4x5x driver to the kernel")
Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Link: https://lore.kernel.org/all/20221206115728.1056014-10-msp@baylibre.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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;
+
 	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
 				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
 	if (ret)