On 9 August 2015 at 14:34, Wolfram Sang [off-list ref] wrote:

On Tue, Jul 28, 2015 at 03:19:44PM +0200, Tomeu Vizoso wrote:

quoted

When looking up an i2c master through its firmware node, probe it if it
hasn't already.

The goal is to reduce deferred probes to a minimum, as it makes it very
cumbersome to find out why a device failed to probe, and can introduce
very big delays in when a critical device is probed.

Signed-off-by: Tomeu Vizoso <redacted>

What is the status of this series?

See here for a summary:

http://lkml.kernel.org/g/1438870315-18689-1-git-send-email-tomeu.vizoso at collabora.com

The boot time reduction sounds great.

Note that this should not reduce total boot time substantially, as the
time wasted due to superfluous probe deferrals is really small when
compared to the time spent in delays due to hardware constraints. If
you want to reduce total boot time, async probing may be helpful in
some scenarios.

Regards,

Tomeu

quoted

---

Changes in v2: None

 drivers/i2c/i2c-core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index e6d4935161e4..5520b413e3db 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c

@@ -1353,6 +1353,8 @@ struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
 {
      struct device *dev;

+     fwnode_ensure_device(&node->fwnode);

TBH, the function name doesn't tell me a lot. It ensures what?

quoted

+
      dev = bus_find_device(&i2c_bus_type, NULL, node,
                                       of_dev_node_match);
      if (!dev)
--
2.4.3