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>
This commit is contained in:
Wolfram Sang 2018-04-28 22:01:02 +02:00 committed by Wolfram Sang
parent 27aaa8ad5a
commit b1437dcb97
1 changed files with 2 additions and 0 deletions

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@ -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);