On Thu, Sep 29, 2011 at 8:23 PM, Brad Campbell lists2009@fnarfbargle.com wrote:
On 29/09/11 23:21, Brad Campbell wrote:
On 29/09/11 22:36, Alex Deucher wrote:
On Thu, Sep 29, 2011 at 10:21 AM, Brad Campbellbrad@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);
Perhaps the delay is causing a problem. Does removing the udelay(400); help?
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; }
Thanks for tracking this down.
Alex
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index 7ad43c6..aacc97d 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -158,14 +158,17 @@ static int radeon_dp_aux_native_read(struct radeon_connector *radeon_connector, while (1) { ret = radeon_process_aux_ch(dig_connector->dp_i2c_bus, msg, msg_bytes, recv, recv_bytes, delay, &ack);
- if (ret == 0)
- if (ret == 0){
- if ((ack & AUX_NATIVE_REPLY_MASK) ==
AUX_NATIVE_REPLY_DEFER){
- udelay(400);
- continue;
- }
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; }