From 655499e2858a559abe52b082d28ff1affe018d4a Mon Sep 17 00:00:00 2001
From: Wesley Yao <wesley.yao@rock-chips.com>
Date: Tue, 31 Dec 2024 17:00:27 +0800
Subject: [PATCH] iio: adc: rockchip-flexbus-adc: Add read memory barrier

Guarantee flexbus has completed transmission before reading.

Change-Id: I38d600a9feb1c0e586e70ec8cb581f803cf7902d
Signed-off-by: Wesley Yao <wesley.yao@rock-chips.com>
---
 drivers/iio/adc/rockchip-flexbus-adc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iio/adc/rockchip-flexbus-adc.c b/drivers/iio/adc/rockchip-flexbus-adc.c
index 4bc653142fce..cf7d1f3f2aaa 100644
--- a/drivers/iio/adc/rockchip-flexbus-adc.c
+++ b/drivers/iio/adc/rockchip-flexbus-adc.c
@@ -175,6 +175,7 @@ static int rockchip_flexbus_adc_read_raw(struct iio_dev *indio_dev,
 			val_mask = 0xffff;
 			break;
 		}
+		dma_rmb();
 		*val = readw(rkfb_adc->dst_buf) & val_mask;
 		return IIO_VAL_INT;