drm/edid: Retry EDID fetch up to four times

This matches the X server's retry logic.  Note that we'll only retry if
we get a DDC response but fail validation; legitimately disconnected
outputs will bomb out early.

See also: http://bugzilla.redhat.com/532957

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Adam Jackson 2009-11-23 14:23:05 -05:00 коммит произвёл Dave Airlie
Родитель f985dedb57
Коммит 47ee4ccf74
1 изменённых файлов: 14 добавлений и 14 удалений

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@ -133,9 +133,6 @@ static bool edid_is_valid(struct edid *edid)
DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);
goto bad;
}
if (edid->revision > 4)
DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");
for (i = 0; i < EDID_LENGTH; i++)
csum += raw_edid[i];
if (csum) {
@ -143,6 +140,9 @@ static bool edid_is_valid(struct edid *edid)
goto bad;
}
if (edid->revision > 4)
DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");
return 1;
bad:
@ -1060,19 +1060,19 @@ static int drm_ddc_read_edid(struct drm_connector *connector,
struct i2c_adapter *adapter,
char *buf, int len)
{
int ret;
int i;
ret = drm_do_probe_ddc_edid(adapter, buf, len);
if (ret != 0) {
goto end;
for (i = 0; i < 4; i++) {
if (drm_do_probe_ddc_edid(adapter, buf, len))
return -1;
if (edid_is_valid((struct edid *)buf))
return 0;
}
if (!edid_is_valid((struct edid *)buf)) {
dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n",
drm_get_connector_name(connector));
ret = -1;
}
end:
return ret;
/* repeated checksum failures; warn, but carry on */
dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n",
drm_get_connector_name(connector));
return -1;
}
/**