On 29/09/11 22:36, Alex Deucher wrote:
> On Thu, Sep 29, 2011 at 10:21 AM, Brad Campbell<brad at fnarfbargle.com>
> wrote:
>> This patch fixes a regression introduced between 2.6.39& 3.1-rc1 whereby
>> the displayport AUX channel stopped re-trying commands that elicited a DEFER
>> response.
>>
> It should still be retrying, just restructured slightly. The retry
> logic just moved into radeon_dp_i2c_aux_ch(),
> radeon_dp_aux_native_write(), and radeon_dp_aux_native_read(), e.g.,
>
> else if ((ack& AUX_NATIVE_REPLY_MASK) ==
> AUX_NATIVE_REPLY_DEFER)
> udelay(400);
One problem with that logic I'm afraid.
if (ret == 0)
return -EPROTO;
if (ret < 0)
return ret;
if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
return ret;
else if ((ack & AUX_NATIVE_REPLY_MASK) ==
AUX_NATIVE_REPLY_DEFER)
udelay(400);
else
return -EIO;
}
ret == 0 with a defer as there is no data in the packet. It never even gets
past the first hurdle.
