From 272479d7ab067344d118e7633b624bf98f8896f3 Mon Sep 17 00:00:00 2001
From: Chris Pascoe <c.pascoe@itee.uq.edu.au>
Date: Mon, 19 Nov 2007 03:01:22 -0300
Subject: [PATCH] V4L/DVB (6626): CXUSB: support only-read i2c requests
Any i2c read request that was not immediately preceded by a write request was
incorrectly taking the write path. Add the capability to handle individual
read requests.
Signed-off-by: Chris Pascoe <c.pascoe@itee.uq.edu.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
---
drivers/media/dvb/dvb-usb/cxusb.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/media/dvb/dvb-usb/cxusb.c b/drivers/media/dvb/dvb-usb/cxusb.c
index 86fbd6c73ea9..016a3780b714 100644
--- a/drivers/media/dvb/dvb-usb/cxusb.c
+++ b/drivers/media/dvb/dvb-usb/cxusb.c
@@ -98,8 +98,21 @@ static int cxusb_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
break;
}
- /* read request */
- if (i+1 < num && (msg[i+1].flags & I2C_M_RD)) {
+ if (msg[i].flags & I2C_M_RD) {
+ /* read only */
+ u8 obuf[3], ibuf[1+msg[i].len];
+ obuf[0] = 0;
+ obuf[1] = msg[i].len;
+ obuf[2] = msg[i].addr;
+ if (cxusb_ctrl_msg(d, CMD_I2C_READ,
+ obuf, 3,
+ ibuf, 1+msg[i].len) < 0) {
+ warn("i2c read failed");
+ break;
+ }
+ memcpy(msg[i].buf, &ibuf[1], msg[i].len);
+ } else if (i+1 < num && (msg[i+1].flags & I2C_M_RD)) {
+ /* write then read */
u8 obuf[3+msg[i].len], ibuf[1+msg[i+1].len];
obuf[0] = msg[i].len;
obuf[1] = msg[i+1].len;
@@ -117,7 +130,8 @@ static int cxusb_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
memcpy(msg[i+1].buf, &ibuf[1], msg[i+1].len);
i++;
- } else { /* write */
+ } else {
+ /* write only */
u8 obuf[2+msg[i].len], ibuf;
obuf[0] = msg[i].addr;
obuf[1] = msg[i].len;
--
2.30.9