From: Ben Dooks <ben.dooks@codethink.co.uk>
To: linux-i2c@vger.kernel.org, SH-Linux <linux-sh@vger.kernel.org>
Subject: rcar-i2c: always reads a byte
Date: Tue, 11 Mar 2014 16:15:02 +0000 [thread overview]
Message-ID: <531F3686.7050808@codethink.co.uk> (raw)
I have noticed the following behaviour with the i2c-rcar driver
with the following single i2c_msg structure:
msg[0].addr = 0x12;
msg[0].flags = I2C_M_RD;
msg[0].len = 0;
msg[0].buf = data;
The system issues an address transaction followed by a single byte
read.
I have tried changing the code to not ack the read after the address
interrupt, however this causes the i2c block to hang forever.
i2c_recv_irq():
if (priv->pos + 1 >= msg->len) {
rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP);
if (msg->len != 0)
rcar_i2c_status_bit_clear(priv, MAT | MDR);
else
rcar_i2c_status_bit_clear(priv, MAT);
} else {
rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_DATA);
rcar_i2c_recv_restart(priv);
}
--
Ben Dooks http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius
next reply other threads:[~2014-03-11 16:15 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-11 16:15 Ben Dooks [this message]
2014-03-11 16:40 ` rcar-i2c: always reads a byte Wolfram Sang
2014-03-11 16:40 ` Wolfram Sang
2014-03-11 16:41 ` Ben Dooks
2014-03-11 16:47 ` Wolfram Sang
2014-03-11 16:47 ` Wolfram Sang
2014-03-11 17:10 ` Ben Dooks
2014-05-05 15:51 ` Wolfram Sang
2014-05-05 15:51 ` Wolfram Sang
2014-03-11 17:24 ` Wolfram Sang
2014-03-11 17:24 ` Wolfram Sang
2014-03-11 17:31 ` Ben Dooks
2014-03-11 17:46 ` Wolfram Sang
2014-03-11 17:46 ` Wolfram Sang
[not found] ` <531F3686.7050808-4yDnlxn2s6sWdaTGBSpHTA@public.gmane.org>
2014-03-12 8:27 ` Michael Lawnick
2014-03-12 8:27 ` Michael Lawnick
2014-03-12 8:39 ` Paul Carpenter
2014-03-12 9:00 ` Michael Lawnick
2014-03-12 9:00 ` Michael Lawnick
[not found] ` <53201A83.7040605-Mmb7MZpHnFY@public.gmane.org>
2014-05-05 13:21 ` Wolfram Sang
2014-05-05 13:21 ` Wolfram Sang
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