[PATCH v2] gpu: host1x: Ignore clients initialization failure

From: Dmitry Osipenko
Date: Thu Aug 09 2018 - 19:12:46 EST


>From time to time new bugs are popping up, causing some host1x client to
fail its initialization. Currently a single clients initialization failure
causes whole host1x device registration to fail, as a result a single DRM
sub-device initialization failure makes whole DRM initialization to fail.
Let's ignore clients initialization failure, as a result display panel
lights up even if some DRM clients (say GR2D or VIC) fail to initialize.
Actually VIC fails if initramfs misses the firmware file, so with this
change a serial console isn't needed anymore to figure out why display
isn't working.

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---

Changelog:

v2: Added WARN_ON() that should get more attention than just a error message.
Made clients_lock to lock around the lists modification, that is in line
with the rest of the code.

drivers/gpu/host1x/bus.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c
index 815bdb42e3f0..07bb6b6c1260 100644
--- a/drivers/gpu/host1x/bus.c
+++ b/drivers/gpu/host1x/bus.c
@@ -199,19 +199,23 @@ static void host1x_subdev_unregister(struct host1x_device *device,
*/
int host1x_device_init(struct host1x_device *device)
{
- struct host1x_client *client;
+ struct host1x_client *client, *cl;
int err;

mutex_lock(&device->clients_lock);

- list_for_each_entry(client, &device->clients, list) {
+ list_for_each_entry_safe(client, cl, &device->clients, list) {
if (client->ops && client->ops->init) {
err = client->ops->init(client);
- if (err < 0) {
+ if (WARN_ON(err < 0)) {
dev_err(&device->dev,
"failed to initialize %s: %d\n",
dev_name(client->dev), err);
- goto teardown;
+
+ /* add the client to the list of idle clients */
+ mutex_lock(&clients_lock);
+ list_add_tail(&client->list, &clients);
+ mutex_unlock(&clients_lock);
}
}
}
@@ -219,14 +223,6 @@ int host1x_device_init(struct host1x_device *device)
mutex_unlock(&device->clients_lock);

return 0;
-
-teardown:
- list_for_each_entry_continue_reverse(client, &device->clients, list)
- if (client->ops->exit)
- client->ops->exit(client);
-
- mutex_unlock(&device->clients_lock);
- return err;
}
EXPORT_SYMBOL(host1x_device_init);

--
2.18.0