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authorWolfram Sang <wsa+renesas@sang-engineering.com>2018-04-28 22:01:02 +0200
committerSimon Horman <horms+renesas@verge.net.au>2018-08-09 17:20:11 +0200
commitdbcb43abfbed963be312ad874af1dc20ea3578a4 (patch)
tree2a98cd4ca92588811c5c663f1c2fb0a2107ddbbf
parent470c31abd517f3dddb7f6f8afd88e13e0809999d (diff)
downloadrenesas-backport-dbcb43abfbed963be312ad874af1dc20ea3578a4.tar.gz
i2c: rcar: enhance comment to avoid regressions
Give a clear testcase for people wishing to change this code. It is also a reminder for me if people ask about it. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> (cherry picked from commit b1437dcb973de79d1f9bca55c6056e8b40ff7ba7) Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
-rw-r--r--drivers/i2c/busses/i2c-rcar.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index c6915b83539658..9d8d5b91220fdf 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -542,6 +542,8 @@ static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
* If next received data is the _LAST_, go to STOP phase. Might be
* overwritten by REP START when setting up a new msg. Not elegant
* but the only stable sequence for REP START I have found so far.
+ * If you want to change this code, make sure sending one transfer with
+ * four messages (WR-RD-WR-RD) works!
*/
if (priv->pos + 1 >= msg->len)
rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);