Add quirk and pm_runtime idle scheduling to let the Master suspend if
no Slaves become attached. This can happen when a link is not marked
as disabled and has devices exposed in the DSDT, if the power is
controlled by sideband means or the link includes a pluggable
connector.
Signed-off-by: Rander Wang <rander.wang@xxxxxxxxxxxxxxx>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
drivers/soundwire/intel.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index b114e9a72fdc..f0077f58c4bf 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -29,8 +29,9 @@
* flags reused in each byte, with master0 using the ls-byte, etc.
*/
-#define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME BIT(0)
-#define SDW_INTEL_MASTER_DISABLE_CLOCK_STOP BIT(1)
+#define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME BIT(0)
+#define SDW_INTEL_MASTER_DISABLE_CLOCK_STOP BIT(1)
+#define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE BIT(2)
static int md_flags;
module_param_named(sdw_md_flags, md_flags, int, 0444);
@@ -1329,6 +1330,22 @@ static int intel_master_startup(struct sdw_master_device *md)
pm_runtime_enable(&md->dev);
}
+ /*
+ * Slave devices have an pm_runtime of 'Unsupported' until
+ * they report as ATTACHED. If they don't, e.g. because there
+ * are no Slave devices populated or if the power-on is
+ * delayed or dependent on a power switch, the Master will
+ * remain active and prevent its parent from suspending.
+ *
+ * Conditionally force the pm_runtime core to re-evaluate the
+ * Master status in the absence of any Slave activity. A quirk
+ * is provided to e.g. deal with Slaves that may be powered on
+ * with a delay. A more complete solution would require the
+ * definition of Master properties.
+ */
+ if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE))
+ pm_runtime_idle(&md->dev);
+
return 0;
err_interrupt:
@@ -1443,6 +1460,7 @@ static int intel_resume(struct device *dev)
struct sdw_master_device *md = to_sdw_master_device(dev);
struct sdw_cdns *cdns = dev_get_drvdata(dev);
struct sdw_intel *sdw = cdns_to_intel(cdns);
+ int link_flags;
int ret;
if (cdns->bus.prop.hw_disabled) {
@@ -1463,6 +1481,10 @@ static int intel_resume(struct device *dev)
pm_runtime_enable(dev);
md->pm_runtime_suspended = false;
+
+ link_flags = md_flags >> (sdw->cdns.bus.link_id * 8);
+ if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE))
+ pm_runtime_idle(&md->dev);
}
ret = intel_init(sdw);
--
2.20.1
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