From 47ee4ccf745ea88ee1aadcf5895d91af3b73ea64 Mon Sep 17 00:00:00 2001 From: Adam Jackson Date: Mon, 23 Nov 2009 14:23:05 -0500 Subject: [PATCH] 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 Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_edid.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index dd95edfcfdc7..282008229f06 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -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; - } - if (!edid_is_valid((struct edid *)buf)) { - dev_warn(&connector->dev->pdev->dev, "%s: EDID invalid.\n", - drm_get_connector_name(connector)); - ret = -1; + 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; } -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; } /** -- 2.30.2