From caf688192bc452c0fdd04920c3ed2405a57ac10b Mon Sep 17 00:00:00 2001 From: Pierre-Louis Bossart Date: Mon, 17 Aug 2020 23:29:20 +0800 Subject: [PATCH] soundwire: intel: add CLK_STOP_NOT_ALLOWED support 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 Signed-off-by: Bard Liao Link: https://lore.kernel.org/r/20200817152923.3259-10-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul --- 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);