Re: [PATCH] bttv: Add support for PCI-8604PW

["Daniel Glöckner" <daniel-gl@gmx.net>]

Hi Hans,

On Mon, Mar 17, 2014 at 10:44:29AM +0100, Hans Verkuil wrote:
> > +		switch (state) {
> > +		case 1:
> > +		case 5:
> > +		case 6:
> > +		case 4:
> > +			pr_debug("PCI-8604PW in state %i, toggling pin\n",
> > +				 state);
> > +			btwrite(0x080000, BT848_GPIO_DATA);
> > +			msleep(1);
> > +			btwrite(0x000000, BT848_GPIO_DATA);
> > +			msleep(1);
> > +			break;
> > +		case 7:
> > +			pr_info("PCI-8604PW unlocked\n");
> > +			return;
> > +		case 0: /* FIXME */
> 
> Fix what? My guess is that if this state happens, then you have no idea how to
> get out of it. Did you actually see this happen, or is this a theoretical case?

yes, if we are in state 7 and toggle GPIO[19] one more time, the CPLD
goes into state 0, where PCI bus mastering is inhibited again.
We have not managed to get out of that state.

> > +			pr_err("PCI-8604PW locked until reset\n");
> > +			return;

> > +		state = (state << 4) | ((btread(BT848_GPIO_DATA) >> 21) & 7);
> > +
> > +		switch (state) {
> > +		case 0x15:
> > +		case 0x56:
> > +		case 0x64:
> > +		case 0x47:
> > +/*		case 0x70: */
> 
> Why is this commented out?

The transition from state 7 to state 0 is, as explained above, valid
but undesired and with this code impossible as we exit as soon as we
are in state 7.

Best regards,

  Daniel