This allows to avoid talking to a non-existent bus repeatedly until we finally timeout. The non-existent bus is signalled by -ENXIO error, provided by i2c_algo_bit:bit_doAddress call.
As the advantage of such change, all the other routines which use drm_get_edid would benefit for this timeout.
As the disadvantage comes the fact that I only tested it on Intel cards, so I am not sure whether it would work on nouveau and radeon.
This change should potentially fix https://bugs.freedesktop.org/show_bug.cgi?id=41059
v2: change printk level to KERN_DEBUG to avoid filling up dmesg
Signed-off-by: Eugeni Dodonov eugeni.dodonov@intel.com --- 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 7425e5c..5ed34f2 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -265,6 +265,11 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf, } }; ret = i2c_transfer(adapter, msgs, 2); + if (ret == -ENXIO) { + printk(KERN_DEBUG "drm: skipping non-existent adapter %s\n", + adapter->name); + break; + } } while (ret != 2 && --retries);
return ret == 2 ? 0 : -1;