@@ -171,7 +171,7 @@ static bool driver_deferred_probe_enable = false;
* changes in the midst of a probe, then deferred processing should be triggered
* again.
*/
-static void driver_deferred_probe_trigger(void)
+void driver_deferred_probe_trigger(void)
{
if (!driver_deferred_probe_enable)
return;
@@ -193,6 +193,7 @@ static void driver_deferred_probe_trigger(void)
*/
queue_work(system_unbound_wq, &deferred_probe_work);
}
+EXPORT_SYMBOL_GPL(driver_deferred_probe_trigger);
/**
* device_block_probing() - Block/defer device's probes
@@ -240,6 +240,7 @@ extern int driver_deferred_probe_timeout;
void driver_deferred_probe_add(struct device *dev);
int driver_deferred_probe_check_state(struct device *dev);
void driver_init(void);
+void driver_deferred_probe_trigger(void);
/**
* module_driver() - Helper macro for drivers that don't do anything
The premise of the deferred probe implementation is that a successful driver binding is a proxy for the resources provided by this driver becoming available. While this is a correct assumption in most of the cases, there are exceptions to the rule such as a) the use of request_firmware_nowait(). In this case, the resources may become available when the 'cont' callback completes, for example when if the firmware needs to be downloaded and executed on a SoC core or DSP. b) a split implementation of the probe with a workqueue when one or ore request_module() calls are required: a synchronous probe prevents other drivers from probing, impacting boot time, and an async probe is not allowed to avoid a deadlock. This is the case on all Intel audio platforms, with request_module() being required for the i915 display audio and HDaudio external codecs. In these cases, there is no way to notify the deferred probe infrastructure of the enablement of resources after the driver binding. The driver_deferred_probe_trigger() function is currently used 'anytime a driver is successfully bound to a device', this patch suggest exporing by exporting it so that drivers can kick-off re-probing of deferred devices at the end of a deferred processing. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> --- drivers/base/dd.c | 3 ++- include/linux/device/driver.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)