diff --git a/drivers/base/regmap/regmap-sdw-mbq.c b/drivers/base/regmap/regmap-sdw-mbq.c
index 6d7c760cbef2..b0312f57c980 100644
--- a/drivers/base/regmap/regmap-sdw-mbq.c
+++ b/drivers/base/regmap/regmap-sdw-mbq.c
@@ -56,7 +56,7 @@ static int regmap_sdw_mbq_poll_busy(struct sdw_slave *slave, unsigned int reg,
 	reg = SDW_SDCA_CTL(SDW_SDCA_CTL_FUNC(reg), 0,
 			   SDCA_CTL_ENTITY_0_FUNCTION_STATUS, 0);
 
-	if (ctx->readable_reg(dev, reg)) {
+	if (!ctx->readable_reg || ctx->readable_reg(dev, reg)) {
 		ret = read_poll_timeout(sdw_read_no_pm, val,
 					val < 0 || !(val & SDCA_CTL_ENTITY_0_FUNCTION_BUSY),
 					ctx->cfg.retry_us, ctx->cfg.timeout_us,