[PATCH] ASoC: cs35l56: Fix possible uninitialized value in cs35l56_spi_system_reset()

[Richard Fitzgerald <rf@opensource.cirrus.com>]

In cs35l56_spi_system_reset() initialize val to zero before using it in
the read_poll_timeout(). This prevents testing an uninitialized value if
the regmap_read_bypassed() returns an error.

Read errors are intentionally ignored during this loop because the
device is resetting (though SPI can't really detect that so shouldn't
fail because of that, it's safer to ignore errors and keep polling).
Because of this, val must be initialized to something in case the first
read fails. The polling loop is looking for a non-zero value, so
initializing val to 0 will ensure that the loop continues until a valid
state is read from the device or it times out.

Fixes: 769c1b79295c ("ASoC: cs35l56: Prevent races when soft-resetting using SPI control")
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
Mark,

This is for-next. Not urgent.

 sound/soc/codecs/cs35l56-shared.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/soc/codecs/cs35l56-shared.c b/sound/soc/codecs/cs35l56-shared.c
index 90e52a678e71..d9f237bf8168 100644
--- a/sound/soc/codecs/cs35l56-shared.c
+++ b/sound/soc/codecs/cs35l56-shared.c
@@ -534,6 +534,7 @@ static void cs35l56_spi_system_reset(struct cs35l56_base *cs35l56_base)
 	 * The regmap must remain in cache-only until the chip has
 	 * booted, so use a bypassed read.
 	 */
+	val = 0;
 	ret = read_poll_timeout(regmap_read_bypassed, read_ret,
 				(val > 0) && (val < 0xffffffff),
 				CS35L56_HALO_STATE_POLL_US,
-- 
2.47.3