On Monday, 13 August 2018 20:48:25 MSK Dmitry Osipenko wrote:
> On Friday, 10 August 2018 02:12:11 MSK Dmitry Osipenko wrote:
> > 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);
>
> This shall be list_move_tail(), v3 is coming.
>
> > + mutex_unlock(&clients_lock);
I just realized that DRM won't load if any of host1x drivers fail to probe. I
think the behaviour should be consistent in a case of driver-probe and client-
init failures. It looks like changing drivers probe error handling will be a
much bigger change, hence let's keep the old behaviour at least for now.
