On Fri, Sep 30, 2011 at 1:14 AM, Brad Campbell
<lists2009 at fnarfbargle.com> wrote:
> On 30/09/11 12:59, Alex Deucher wrote:
>>
>> On Thu, Sep 29, 2011 at 8:23 PM, Brad Campbell
>
>>> Looking at it with a nights sleep, it's obvious the code path in
>>> aux_native_write is ok. Is this a bit cleaner than the last patch?
>>
>> Looks pretty good. ?I was thinking of something more like this (sorry
>> for the lack of a patch, I'm away from my source trees at the moment):
>>
>> ? ? ? ?while (1) {
>> ? ? ? ? ? ? ? ?ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus,
>> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?msg, msg_bytes, recv,
>> recv_bytes, delay,&ack);
>>
>> ? ? ? ? ? ? ? ?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 if (ret == 0)
>> ? ? ? ? ? ? ? ? ? ? ? ?return -EPROTO;
>> ? ? ? ? ? ? ? ?else
>> ? ? ? ? ? ? ? ? ? ? ? ?return -EIO;
>> ? ? ? ?}
>
> Yep, that looks cleaner.
>
> My only thought was the pre-3.0 code had a limit to the number of retries.
> Was that for a specific reason or is it ok to attempt to retry indefinitely
> if we receive a DEFER ?I need to double check the DP spec, but I think it's 4. The while (1) loops in radeon_dp_aux_native_write() and radeon_dp_aux_native_read() should probably be changed to: for (retry = 0; retry < 4; retry++) to match what we do in radeon_dp_i2c_aux_ch(). Alex
