From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
In case the clock needs to keep running, we need to prevent the Master
from entering pm_runtime suspend.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
drivers/soundwire/intel.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index ad476e9e4d25..95b14c034ea7 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1367,6 +1367,7 @@ int intel_master_startup(struct platform_device *pdev)
struct sdw_intel *sdw = cdns_to_intel(cdns);
struct sdw_bus *bus = &cdns->bus;
int link_flags;
+ u32 clock_stop_quirks;
int ret;
if (bus->prop.hw_disabled) {
@@ -1423,6 +1424,20 @@ int intel_master_startup(struct platform_device *pdev)
pm_runtime_enable(dev);
}
+ clock_stop_quirks = sdw->link_res->clock_stop_quirks;
+ if (clock_stop_quirks & SDW_INTEL_CLK_STOP_NOT_ALLOWED) {
+ /*
+ * To keep the clock running we need to prevent
+ * pm_runtime suspend from happening by increasing the
+ * reference count.
+ * This quirk is specified by the parent PCI device in
+ * case of specific latency requirements. It will have
+ * no effect if pm_runtime is disabled by the user via
+ * a module parameter for testing purposes.
+ */
+ pm_runtime_get_noresume(dev);
+ }
+
/*
* The runtime PM status of Slave devices is "Unsupported"
* until they report as ATTACHED. If they don't, e.g. because
@@ -1454,6 +1469,11 @@ static int intel_master_remove(struct platform_device *pdev)
struct sdw_intel *sdw = cdns_to_intel(cdns);
struct sdw_bus *bus = &cdns->bus;
+ /*
+ * Since pm_runtime is already disabled, we don't decrease
+ * the refcount when the clock_stop_quirk is
+ * SDW_INTEL_CLK_STOP_NOT_ALLOWED
+ */
if (!bus->prop.hw_disabled) {
intel_debugfs_exit(sdw);
sdw_cdns_enable_interrupt(cdns, false);
--
2.17.1
