diff options
| author | Eugeni Dodonov <eugeni.dodonov@intel.com> | 2012-01-05 09:34:28 -0200 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2012-02-03 09:38:52 +0000 |
| commit | 9292f37e1f5c79400254dca46f83313488093825 (patch) | |
| tree | 9367e62ee7f583c89a8b52c270befb3ac95fd30b | |
| parent | 30388c6e48e62b2806b14552275f091e2f5adbf4 (diff) | |
drm: give up on edid retries when i2c bus is not responding
This allows to avoid talking to a non-responding bus repeatedly until we
finally timeout after 15 attempts. We can do this by catching the -ENXIO
error, provided by i2c_algo_bit:bit_doAddress call.
Within the bit_doAddress we already try 3 times to get the edid data, so
if the routine tells us that bus is not responding, it is mostly pointless
to keep re-trying those attempts over and over again until we reach final
number of retries.
This change should fix https://bugs.freedesktop.org/show_bug.cgi?id=41059
and improve overall edid detection timing by 10-30% in most cases, and by
a much larger margin in case of phantom outputs (up to 30x in one worst
case).
Timing results for i915-powered machines for 'time xrandr' command:
Machine 1: from 0.840s to 0.290s
Machine 2: from 0.315s to 0.280s
Machine 3: from +/- 4s to 0.184s
Timing results for HD5770 with 'time xrandr' command:
Machine 4: from 3.210s to 1.060s
Reviewed-by: Chris Wilson <chris@hchris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>
Tested-by: Sean Finney <seanius@seanius.net>
Tested-by: Soren Hansen <soren@linux2go.dk>
Tested-by: Hernando Torque <sirius@sonnenkinder.org>
Tested-by: Mike Lothian <mike@fireburn.co.uk>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41059
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
| -rw-r--r-- | drivers/gpu/drm/drm_edid.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index ece03fc2d386..54a4efa0eef7 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -266,6 +266,11 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf, } }; ret = i2c_transfer(adapter, msgs, 2); + if (ret == -ENXIO) { + DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n", + adapter->name); + break; + } } while (ret != 2 && --retries); return ret == 2 ? 0 : -1; |