The Soundwire master controllers might want to check for bus->md initialization to avoid race between early interrupt and finish of sdw_bus_master_add()/sdw_master_device_add(). Such early interrupt can happen if Soundwire devices are not powered off during their probe.
Add a store release barrier, so the Soundwire controllers can safely check it in concurrent (e.g. in interrupt) way.
Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org
---
Cc: Patrick Lai quic_plai@quicinc.com --- drivers/soundwire/master.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/soundwire/master.c b/drivers/soundwire/master.c index 9b05c9e25ebe..d5bf13e7e602 100644 --- a/drivers/soundwire/master.c +++ b/drivers/soundwire/master.c @@ -161,7 +161,12 @@ int sdw_master_device_add(struct sdw_bus *bus, struct device *parent, /* add shortcuts to improve code readability/compactness */ md->bus = bus; bus->dev = &md->dev; - bus->md = md; + /* + * Make sure the contents of md is stored before storing bus->md. + * Paired with new slave attached and slave status interrupts + * on the Soundwire master side. + */ + smp_store_release(&bus->md, md);
pm_runtime_set_autosuspend_delay(&bus->md->dev, SDW_MASTER_SUSPEND_DELAY_MS); pm_runtime_use_autosuspend(&bus->md->dev);