V4L/DVB (6627): CXUSB: handle write then read from different address
The path to perform a read immediately after a write was not checking that
the address being read from was the same as the one that was written.
Handling this case correctly should mean that we now can handle more than
two i2c messages at a time.
Signed-off-by: Chris Pascoe <c.pascoe@itee.uq.edu.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/dvb/dvb-usb/cxusb.c b/drivers/media/dvb/dvb-usb/cxusb.c
index 016a378..74eeb16 100644
--- a/drivers/media/dvb/dvb-usb/cxusb.c
+++ b/drivers/media/dvb/dvb-usb/cxusb.c
@@ -83,9 +83,6 @@
if (mutex_lock_interruptible(&d->i2c_mutex) < 0)
return -EAGAIN;
- if (num > 2)
- warn("more than two i2c messages at a time is not handled yet. TODO.");
-
for (i = 0; i < num; i++) {
if (d->udev->descriptor.idVendor == USB_VID_MEDION)
@@ -111,8 +108,9 @@
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 */
+ } else if (i+1 < num && (msg[i+1].flags & I2C_M_RD) &&
+ msg[i].addr == msg[i+1].addr) {
+ /* write to then read from same address */
u8 obuf[3+msg[i].len], ibuf[1+msg[i+1].len];
obuf[0] = msg[i].len;
obuf[1] = msg[i+1].len;