On 03/17/2014 12:59 PM, Daniel Glöckner wrote:
> 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.
Can you post a new version with comments that explain this?
This is non-obvious information that should be documented in the code.
Thanks!
Hans
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