From: Esben Haabendal <eha@doredevelopment.dk>
To: linux-i2c@vger.kernel.org
Cc: linuxppc-dev@ozlabs.org
Subject: [PATCH] i2c-mpc: generate START condition after STOP caused by read i2c_msg
Date: Thu, 14 May 2009 10:10:03 +0200 [thread overview]
Message-ID: <4A0BD1DB.4090305@doredevelopment.dk> (raw)
This fixes MAL (arbitration lost) bug caused by illegal use of
RSTA (repeated START) after STOP condition generated after last byte
of reads.
Signed-off-by: Esben Haabendal <eha@doredevelopment.dk>
---
drivers/i2c/busses/i2c-mpc.c | 9 +++++++--
1 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 4af5c09..9fe05d9 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -456,17 +456,22 @@ static int mpc_xfer(struct i2c_adapter *adap,
struct i2c_msg *msgs, int num)
}
for (i = 0; ret >= 0 && i < num; i++) {
+ int restart = i;
pmsg = &msgs[i];
dev_dbg(i2c->dev,
"Doing %s %d bytes to 0x%02x - %d of %d messages\n",
pmsg->flags & I2C_M_RD ? "read" : "write",
pmsg->len, pmsg->addr, i + 1, num);
+ if (i > 0 && ((pmsg-1)->flags & I2C_M_RD))
+ restart = 0;
if (pmsg->flags & I2C_M_RD)
ret =
- mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
+ mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len,
+ restart);
else
ret =
- mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
+ mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len,
+ restart);
}
mpc_i2c_stop(i2c);
return (ret < 0) ? ret : num;
--
1.6.0.4
next reply other threads:[~2009-05-14 8:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-14 8:10 Esben Haabendal [this message]
2009-05-14 8:34 ` [PATCH] i2c-mpc: generate START condition after STOP caused by read i2c_msg Wolfram Sang
2009-05-14 8:48 ` Esben Haabendal
2009-05-14 9:58 ` Joakim Tjernlund
[not found] ` <d2b9ea600905140317u7a4b9a70s574568d79a1ce7cc@mail.gmail.com>
2009-05-14 16:52 ` Joakim Tjernlund
2009-05-15 10:18 ` Esben Haabendal
2009-05-15 11:05 ` Joakim Tjernlund
2009-05-15 12:52 ` Esben Haabendal
2009-05-15 14:16 ` Joakim Tjernlund
2009-05-18 11:04 ` Wolfram Sang
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