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[PATCH 0/1] regmap: drop cache if the bus transfer error

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regmap_write
->_regmap_raw_write
-->regcache_write first and than use map->bus->write to wirte i2c or spi
But if the i2c or spi transfer failed, But the cache is updated, So if I use
regmap_read will get the cache data which is not the real register value.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
---
 drivers/base/regmap/regmap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 1f011f9d6dcb..369a4c3c933e 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1497,6 +1497,8 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
 		ret = map->bus->write(map->bus_context, buf, len);
 
 		kfree(buf);
+	} else if (ret != 0 && !map->cache_bypass && map->format.parse_val) {
+		regcache_drop_region(map, reg, reg + 1);
 	}
 
 	trace_regmap_hw_write_done(map, reg, val_len / map->format.val_bytes);
-- 
1.9.1

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[PATCH 0/1] regmap: drop cache if the bus transfer error Elaine Zhang <zhangqing@rock-chips.com> - 2016-08-18 08:50 +0200
  Applied "regmap: drop cache if the bus transfer error" to the regmap tree Mark Brown <broonie@kernel.org> - 2016-08-18 12:20 +0200

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