media: imx8mq-mipi-csi2: Explicitly release reset

Call reset_control_deassert() to explicitly release reset to make sure
reset bits are cleared since platform like i.MX8ULP can't clear reset
bits automatically.

Reviewed-by: Frank Li <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Signed-off-by: Guoniu Zhou <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Laurent Pinchart <[email protected]>
Signed-off-by: Hans Verkuil <[email protected]>

drivers/media/platform/nxp/imx8mq-mipi-csi2.c

@@ -339,18 +339,14 @@ static int imx8mq_mipi_csi_sw_reset(struct csi_state *state)
 {
 	int ret;
 
-	/*
-	 * these are most likely self-clearing reset bits. to make it
-	 * more clear, the reset-imx7 driver should implement the
-	 * .reset() operation.
-	 */
 	ret = reset_control_assert(state->rst);
 	if (ret < 0) {
 		dev_err(state->dev, "Failed to assert resets: %d\n", ret);
 		return ret;
 	}
 
-	return 0;
+	/* Explicitly release reset to make sure reset bits are cleared. */
+	return reset_control_deassert(state->rst);
 }
 
 static void imx8mq_mipi_csi_set_params(struct csi_state *state)