From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> We recently added the ability to discard bus clash interrupts reported on startup. These bus clash interrupts can happen randomly on some platforms and don't seem to be valid. A master-level quirk helped squelch those spurious errors. Additional tests on a new platform with the Maxim 98373 amplifier showed a rare case where the parity interrupt is also thrown on startup, at the same time as bus clashes. This issue only seems to happen infrequently and was only observed during suspend-resume stress tests while audio is streaming. We could make the problem go away by adding a Slave-level quirk, but there is no evidence that the issue is actually a Slave problem: the parity is provided by the Master, which could also set an invalid parity in corner cases. This patch suggests an additional bus-level quirk for parity, which is only applied when the codec device is not known to have an issue with parity. The initial parity error will be ignored, but a trace will be logged to help identify potential root causes (likely a combination of issues on both master and slave sides influenced by board-specific electrical parameters). BugLink: https://github.com/thesofproject/linux/issues/2533 Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx> Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx> --- drivers/soundwire/bus.c | 9 +++++++++ drivers/soundwire/intel.c | 3 ++- include/linux/soundwire/sdw.h | 1 + 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index d394905936e4..57581fdb2ea9 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -1256,6 +1256,15 @@ static int sdw_initialize_slave(struct sdw_slave *slave) sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_BUS_CLASH); } } + if ((slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY) && + !(slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY)) { + /* Clear parity interrupt before enabling interrupt mask */ + status = sdw_read_no_pm(slave, SDW_SCP_INT1); + if (status & SDW_SCP_INT1_PARITY) { + dev_warn(&slave->dev, "PARITY error detected before INT mask is enabled\n"); + sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_PARITY); + } + } /* * Set SCP_INT1_MASK register, typically bus clash and diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index f7ba1a77a1df..c1fdc85d0a74 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -1286,7 +1286,8 @@ static int sdw_master_read_intel_prop(struct sdw_bus *bus) if (quirk_mask & SDW_INTEL_QUIRK_MASK_BUS_DISABLE) prop->hw_disabled = true; - prop->quirks = SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH; + prop->quirks = SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH | + SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY; return 0; } diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index a2766c3b603d..30415354d419 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -426,6 +426,7 @@ struct sdw_master_prop { }; #define SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH BIT(0) +#define SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY BIT(1) int sdw_master_read_prop(struct sdw_bus *bus); int sdw_slave_read_prop(struct sdw_slave *slave); -- 2.17.1
