From: Luotao Fu <l.fu-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
To: Vitaly Wool <vitalywool-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>,
Ben Dooks <ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org>,
Kevin Wells <kevin.wells-3arQi8VN3Tc@public.gmane.org>,
Julia Lawall <julia-dAYI7NvHqcQ@public.gmane.org>,
Russell King <rmk+kernel-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Luotao Fu <l.fu-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Subject: [PATCH] i2c-pnx: fix setting start/stop condition
Date: Mon, 1 Mar 2010 13:24:24 +0100 [thread overview]
Message-ID: <1267446264-8446-1-git-send-email-l.fu@pengutronix.de> (raw)
The start/stop condtions are set in different places repetedly in the i2c-pnx
driver. Beside in i2c_pnx_start and i2c_pnx_stop the start/stop bit are also
set during the transfer of a i2c message in the master_xmit/rcv calls. This is
wrong since we can't set the start/stop condition during the transaction of a
single message any way. As a matter of fact, the driver will sometimes set both
the start and the stop bits at one time. This can be easily reproduced by
sending a simple read request like e.g
struct i2c_msg msgs[] = {
{ addr, 0, 1, buf },
{ addr, I2C_M_RD, offset, buf }
};
While processing the first message the i2c_pnx_master_xmit will set both the
start_bit and the stop_bit, which will eventually confuse the slave.
Fixed by remove setting start/stop condition from the transmit routines.
Signed-off-by: Luotao Fu <l.fu-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
drivers/i2c/busses/i2c-pnx.c | 11 -----------
1 files changed, 0 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/busses/i2c-pnx.c b/drivers/i2c/busses/i2c-pnx.c
index 5d1c260..92c0e46 100644
--- a/drivers/i2c/busses/i2c-pnx.c
+++ b/drivers/i2c/busses/i2c-pnx.c
@@ -175,12 +175,6 @@ static int i2c_pnx_master_xmit(struct i2c_adapter *adap)
/* We still have something to talk about... */
val = *alg_data->mif.buf++;
- if (alg_data->mif.len == 1) {
- val |= stop_bit;
- if (!alg_data->last)
- val |= start_bit;
- }
-
alg_data->mif.len--;
iowrite32(val, I2C_REG_TX(alg_data));
@@ -252,11 +246,6 @@ static int i2c_pnx_master_rcv(struct i2c_adapter *adap)
"Rx-fifo...\n", __func__);
if (alg_data->mif.len == 1) {
- /* Last byte, do not acknowledge next rcv. */
- val |= stop_bit;
- if (!alg_data->last)
- val |= start_bit;
-
/*
* Enable interrupt RFDAIE (data in Rx fifo),
* and disable DRMIE (need data for Tx)
--
1.7.0
next reply other threads:[~2010-03-01 12:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-01 12:24 Luotao Fu [this message]
[not found] ` <1267446264-8446-1-git-send-email-l.fu-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2010-03-01 14:13 ` [PATCH] i2c-pnx: fix setting start/stop condition Vitaly Wool
2010-03-01 18:43 ` Kevin Wells
[not found] ` <083DF309106F364B939360100EC290F805CCF9294A-SIPbe8o7cfX8DdpCu65jn8FrZmdRls4ZQQ4Iyu8u01E@public.gmane.org>
2010-03-01 19:19 ` Luotao Fu
[not found] ` <20100301191954.GA1811-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2010-03-02 1:12 ` Kevin Wells
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