On Fri, Sep 30, 2011 at 1:14 AM, Brad Campbell lists2009@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