monitor-manager-kms: Handle EDID blob not being ready immediately

Sometimes we hit a race on hot-plug where we try to read the KMS
resources and the EDID blob is not yet ready. This would normally
result in a ENOENT when retrieving the blob. Handle this by retrying
after 50 milliseconds after a hot-plug event. Do this up to 10 times,
and after that give up trying to get the EDID blob and continue with
best effort.

https://bugzilla.gnome.org/show_bug.cgi?id=777732
This commit is contained in:
Jonas Ådahl 2016-12-21 16:00:29 +08:00
parent 4c1b48d0cc
commit 8c5600e81b

View File

@ -51,6 +51,10 @@
#define ALL_TRANSFORMS_MASK ((1 << ALL_TRANSFORMS) - 1)
#define SYNC_TOLERANCE 0.01 /* 1 percent */
/* Try each 50 milleseconds up to half a second to get a proper EDID read */
#define EDID_RETRY_TIMEOUT_MS 50
#define EDID_MAX_NUM_RETRIES 10
typedef struct {
drmModeConnector *connector;
@ -109,6 +113,9 @@ struct _MetaMonitorManagerKms
GSettings *desktop_settings;
gboolean page_flips_not_supported;
guint handle_hotplug_timeout;
int read_edid_tries;
};
struct _MetaMonitorManagerKmsClass
@ -310,33 +317,48 @@ find_crtc_properties (MetaMonitorManagerKms *manager_kms,
}
}
static GBytes *
read_output_edid (MetaMonitorManagerKms *manager_kms,
MetaOutput *output)
static drmModePropertyBlobPtr
read_edid_blob (MetaMonitorManagerKms *manager_kms,
uint32_t edid_blob_id,
GError **error)
{
MetaOutputKms *output_kms = output->driver_private;
drmModePropertyBlobPtr edid_blob = NULL;
if (output_kms->edid_blob_id == 0)
return NULL;
edid_blob = drmModeGetPropertyBlob (manager_kms->fd, output_kms->edid_blob_id);
edid_blob = drmModeGetPropertyBlob (manager_kms->fd, edid_blob_id);
if (!edid_blob)
{
meta_warning ("Failed to read EDID of output %s: %s\n", output->name, strerror(errno));
g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),
"Failed to get EDID property blob: %s", strerror (errno));
return NULL;
}
if (edid_blob->length > 0)
{
return g_bytes_new_with_free_func (edid_blob->data, edid_blob->length,
(GDestroyNotify)drmModeFreePropertyBlob, edid_blob);
return edid_blob;
}
else
static GBytes *
read_output_edid (MetaMonitorManagerKms *manager_kms,
MetaOutput *output,
GError **error)
{
MetaOutputKms *output_kms = output->driver_private;
drmModePropertyBlobPtr edid_blob;
g_assert (output_kms->edid_blob_id != 0);
edid_blob = read_edid_blob (manager_kms, output_kms->edid_blob_id, error);
if (!edid_blob)
return NULL;
if (edid_blob->length == 0)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED, "EDID blob was empty");
drmModeFreePropertyBlob (edid_blob);
return NULL;
}
return g_bytes_new_with_free_func (edid_blob->data, edid_blob->length,
(GDestroyNotify) drmModeFreePropertyBlob,
edid_blob);
}
static gboolean
@ -874,7 +896,22 @@ init_output (MetaOutput *output,
output->suggested_y = output_kms->suggested_y;
output->hotplug_mode_update = output_kms->hotplug_mode_update;
edid = read_output_edid (manager_kms, output);
if (output_kms->edid_blob_id != 0)
{
GError *error = NULL;
edid = read_output_edid (manager_kms, output, &error);
if (!edid)
{
g_warning ("Failed to read EDID: %s", error->message);
g_error_free (error);
}
}
else
{
edid = NULL;
}
meta_output_parse_edid (output, edid);
g_bytes_unref (edid);
@ -1190,9 +1227,24 @@ static GBytes *
meta_monitor_manager_kms_read_edid (MetaMonitorManager *manager,
MetaOutput *output)
{
MetaOutputKms *output_kms = output->driver_private;
MetaMonitorManagerKms *manager_kms = META_MONITOR_MANAGER_KMS (manager);
GError *error = NULL;
GBytes *edid;
return read_output_edid (manager_kms, output);
if (output_kms->edid_blob_id == 0)
return NULL;
edid = read_output_edid (manager_kms, output, &error);
if (!edid)
{
g_warning ("Failed to read EDID from '%s': %s",
output->name, error->message);
g_error_free (error);
return NULL;
}
return edid;
}
static void
@ -1460,6 +1512,114 @@ meta_monitor_manager_kms_set_crtc_gamma (MetaMonitorManager *manager,
drmModeCrtcSetGamma (manager_kms->fd, crtc->crtc_id, size, red, green, blue);
}
static gboolean
has_pending_edid_blob (MetaMonitorManagerKms *manager_kms)
{
drmModeRes *resources;
int n_connectors;
int i, j;
gboolean edid_blob_pending;
resources = drmModeGetResources (manager_kms->fd);
n_connectors = resources->count_connectors;
edid_blob_pending = FALSE;
for (i = 0; i < n_connectors; i++)
{
drmModeConnector *drm_connector;
uint32_t edid_blob_id;
drm_connector = drmModeGetConnector (manager_kms->fd,
resources->connectors[i]);
edid_blob_id = 0;
for (j = 0; j < drm_connector->count_props; j++)
{
drmModePropertyPtr prop;
prop = drmModeGetProperty (manager_kms->fd, drm_connector->props[j]);
if (prop->flags & DRM_MODE_PROP_BLOB &&
g_str_equal (prop->name, "EDID"))
edid_blob_id = drm_connector->prop_values[j];
drmModeFreeProperty (prop);
if (edid_blob_id)
break;
}
drmModeFreeConnector (drm_connector);
if (edid_blob_id)
{
GError *error = NULL;
drmModePropertyBlobPtr edid_blob;
edid_blob = read_edid_blob (manager_kms, edid_blob_id, &error);
if (!edid_blob &&
g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
{
edid_blob_pending = TRUE;
g_error_free (error);
}
else if (!edid_blob)
{
g_error_free (error);
}
else
{
drmModeFreePropertyBlob (edid_blob);
}
}
if (edid_blob_pending)
break;
}
drmModeFreeResources (resources);
return edid_blob_pending;
}
static void
handle_hotplug_event (MetaMonitorManager *manager)
{
meta_monitor_manager_read_current_state (manager);
meta_monitor_manager_on_hotplug (manager);
}
static gboolean
handle_hotplug_event_timeout (gpointer user_data)
{
MetaMonitorManager *manager = user_data;
MetaMonitorManagerKms *manager_kms = META_MONITOR_MANAGER_KMS (user_data);
if (!has_pending_edid_blob (manager_kms))
{
handle_hotplug_event (manager);
manager_kms->handle_hotplug_timeout = 0;
return G_SOURCE_REMOVE;
}
manager_kms->read_edid_tries++;
if (manager_kms->read_edid_tries > EDID_MAX_NUM_RETRIES)
{
g_warning ("Tried to read the EDID %d times, "
"but one or more are still missing, continuing without",
manager_kms->read_edid_tries);
handle_hotplug_event (manager);
manager_kms->handle_hotplug_timeout = 0;
return G_SOURCE_REMOVE;
}
return G_SOURCE_CONTINUE;
}
static void
on_uevent (GUdevClient *client,
const char *action,
@ -1472,9 +1632,29 @@ on_uevent (GUdevClient *client,
if (!g_udev_device_get_property_as_boolean (device, "HOTPLUG"))
return;
meta_monitor_manager_read_current_state (manager);
if (manager_kms->handle_hotplug_timeout)
{
g_source_remove (manager_kms->handle_hotplug_timeout);
manager_kms->handle_hotplug_timeout = 0;
}
meta_monitor_manager_on_hotplug (manager);
/*
* On a hot-plug event, the EDID of one or more connectors might not yet be
* ready at this point, resulting in invalid configuration potentially being
* applied. Avoid this by first checking whether the EDID is ready at this
* point, or otherwise wait a bit and try again.
*/
manager_kms->read_edid_tries = 0;
if (has_pending_edid_blob (manager_kms))
{
manager_kms->handle_hotplug_timeout =
g_timeout_add (EDID_RETRY_TIMEOUT_MS,
handle_hotplug_event_timeout,
manager);
return;
}
handle_hotplug_event (manager);
}
static gboolean