Re: WinTV-HVR-1400: scandvb (and kaffeine) fails to find any channels

[Chris Clayton <chris2553@googlemail.com>]

On 02/05/13 14:48, Chris Clayton wrote:
>
[snip]
>
> Well, after lots of hacking diagnostics into cx23885-i2c.c, I'm pretty
> sure that this is a timing problem. I've eventually found that if I
> insert a short delay into the top of i2c_sendbytes(), my HVR-1400
> expresscard dvb-t gadget starts to work. When I run a dvb scan, it finds
> all 117 services that are found using the same device on Windows 7 (and
> by a nearby Samsung TV). I have no idea why the delay makes the card work.
>
> A patch that makes this change is:
>
[snip]
OK, here's what I believe to be a better version of the patch:

--- linux-3.7.6/drivers/media/pci/cx23885/cx23885-i2c.c~ 
2013-02-01 19:46:56.000000000 +0000
+++ linux-3.7.6/drivers/media/pci/cx23885/cx23885-i2c.c 2013-02-06 
11:08:31.000000000 +0000
@@ -92,6 +92,13 @@ static int i2c_sendbytes(struct i2c_adap
         else
                 dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);

+       /* The XC3028L tuner on a WinTV-HVR-1400 fails to tune without 
this */
+       if (dev->board == CX23885_BOARD_HAUPPAUGE_HVR1400) {
+               printk_once(KERN_INFO "%s - extra delay being applied for "
+                           "HVR1400\n", i2c_adap->name);
+               udelay(8);
+       }
+
         /* Deal with i2c probe functions with zero payload */
         if (msg->len == 0) {
                 cx_write(bus->reg_addr, msg->addr << 25);

Signed-off-by: Chris Clayton <chris2553@googlemail.com>

It applies cleanly to 3.7.6 and to 3.80-rc6+ (pulled this morning).

Chris