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authorRander Wang <rander.wang@intel.com>2020-08-17 23:29:23 +0800
committerVinod Koul <vkoul@kernel.org>2020-08-18 12:01:05 +0530
commit08abad9f45f105e947d91822bdbc47650fbd7773 (patch)
tree1c8d29542f3a86830c430e63661f1449cbbe3bb6 /drivers/soundwire
parent61fb830bf9ca02f040fdfe65b714bea492a44986 (diff)
soundwire: intel: refine runtime pm for SDW_INTEL_CLK_STOP_BUS_RESET
When all the links are suspended, the HDaudio controller may suspend and the power rails to the SoundWire IP may be disabled, requiring a complete re-initialization/enumeration on resume. However, if one or more Masters remained active, the HDaudio controller will remain active and the power rails will remain enabled. As a result, during the link resume step we can check if the context was preserved by verifying if the clock was stopped, and avoid doing a complete bus reset and re-enumeration. Signed-off-by: Rander Wang <rander.wang@intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20200817152923.3259-13-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/soundwire')
-rw-r--r--drivers/soundwire/intel.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 2899445e2649..dbcbe2708563 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1698,6 +1698,8 @@ static int intel_resume_runtime(struct device *dev)
struct sdw_intel *sdw = cdns_to_intel(cdns);
struct sdw_bus *bus = &cdns->bus;
u32 clock_stop_quirks;
+ bool clock_stop0;
+ int status;
int ret;
if (bus->prop.hw_disabled) {
@@ -1740,10 +1742,23 @@ static int intel_resume_runtime(struct device *dev)
}
/*
+ * An exception condition occurs for the CLK_STOP_BUS_RESET
+ * case if one or more masters remain active. In this condition,
+ * all the masters are powered on for they are in the same power
+ * domain. Master can preserve its context for clock stop0, so
+ * there is no need to clear slave status and reset bus.
+ */
+ clock_stop0 = sdw_cdns_is_clock_stop(&sdw->cdns);
+
+ /*
* make sure all Slaves are tagged as UNATTACHED and
* provide reason for reinitialization
*/
- sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);
+ if (!clock_stop0) {
+ status = SDW_UNATTACH_REQUEST_MASTER_RESET;
+ sdw_clear_slave_status(bus, status);
+ }
+
ret = sdw_cdns_enable_interrupt(cdns, true);
if (ret < 0) {
@@ -1751,7 +1766,7 @@ static int intel_resume_runtime(struct device *dev)
return ret;
}
- ret = sdw_cdns_clock_restart(cdns, true);
+ ret = sdw_cdns_clock_restart(cdns, !clock_stop0);
if (ret < 0) {
dev_err(dev, "unable to restart clock during resume\n");
return ret;