[PATCH 0/3] soundwire: improve bus reset
Improve bus reset sequence by updating programing sequence.
Pierre-Louis Bossart (3): soundwire: intel_bus_common: enable interrupts last soundwire: intel/cadence: update hardware reset sequence soundwire: cadence: revisit parity injection
drivers/soundwire/cadence_master.c | 50 ++++++++++----- drivers/soundwire/cadence_master.h | 3 + drivers/soundwire/intel_bus_common.c | 93 ++++++++++++++++------------ 3 files changed, 89 insertions(+), 57 deletions(-)
From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
It's not clear why we enabled interrupts in the Cadence IP first. The logical programming sequence should be to first start the bus, and only second to enable the interrupts.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/intel_bus_common.c | 61 +++++++++++++--------------- 1 file changed, 28 insertions(+), 33 deletions(-)
diff --git a/drivers/soundwire/intel_bus_common.c b/drivers/soundwire/intel_bus_common.c index f180e3bea989..901d4f5736c1 100644 --- a/drivers/soundwire/intel_bus_common.c +++ b/drivers/soundwire/intel_bus_common.c @@ -16,12 +16,6 @@ int intel_start_bus(struct sdw_intel *sdw) struct sdw_bus *bus = &cdns->bus; int ret;
- ret = sdw_cdns_enable_interrupt(cdns, true); - if (ret < 0) { - dev_err(dev, "%s: cannot enable interrupts: %d\n", __func__, ret); - return ret; - } - /* * follow recommended programming flows to avoid timeouts when * gsync is enabled @@ -32,30 +26,33 @@ int intel_start_bus(struct sdw_intel *sdw) ret = sdw_cdns_init(cdns); if (ret < 0) { dev_err(dev, "%s: unable to initialize Cadence IP: %d\n", __func__, ret); - goto err_interrupt; + return ret; }
ret = sdw_cdns_exit_reset(cdns); if (ret < 0) { dev_err(dev, "%s: unable to exit bus reset sequence: %d\n", __func__, ret); - goto err_interrupt; + return ret; }
if (bus->multi_link) { ret = sdw_intel_sync_go(sdw); if (ret < 0) { dev_err(dev, "%s: sync go failed: %d\n", __func__, ret); - goto err_interrupt; + return ret; } } + + ret = sdw_cdns_enable_interrupt(cdns, true); + if (ret < 0) { + dev_err(dev, "%s: cannot enable interrupts: %d\n", __func__, ret); + return ret; + } + sdw_cdns_check_self_clearing_bits(cdns, __func__, true, INTEL_MASTER_RESET_ITERATIONS);
return 0; - -err_interrupt: - sdw_cdns_enable_interrupt(cdns, false); - return ret; }
int intel_start_bus_after_reset(struct sdw_intel *sdw) @@ -86,12 +83,6 @@ int intel_start_bus_after_reset(struct sdw_intel *sdw) status = SDW_UNATTACH_REQUEST_MASTER_RESET; sdw_clear_slave_status(bus, status);
- ret = sdw_cdns_enable_interrupt(cdns, true); - if (ret < 0) { - dev_err(dev, "cannot enable interrupts during resume\n"); - return ret; - } - /* * follow recommended programming flows to avoid * timeouts when gsync is enabled @@ -115,31 +106,36 @@ int intel_start_bus_after_reset(struct sdw_intel *sdw) ret = sdw_cdns_clock_restart(cdns, !clock_stop0); if (ret < 0) { dev_err(dev, "unable to restart clock during resume\n"); - goto err_interrupt; + if (!clock_stop0) + sdw_cdns_enable_interrupt(cdns, false); + return ret; }
if (!clock_stop0) { ret = sdw_cdns_exit_reset(cdns); if (ret < 0) { dev_err(dev, "unable to exit bus reset sequence during resume\n"); - goto err_interrupt; + return ret; }
if (bus->multi_link) { ret = sdw_intel_sync_go(sdw); if (ret < 0) { dev_err(sdw->cdns.dev, "sync go failed during resume\n"); - goto err_interrupt; + return ret; } } + + ret = sdw_cdns_enable_interrupt(cdns, true); + if (ret < 0) { + dev_err(dev, "cannot enable interrupts during resume\n"); + return ret; + } + } sdw_cdns_check_self_clearing_bits(cdns, __func__, true, INTEL_MASTER_RESET_ITERATIONS);
return 0; - -err_interrupt: - sdw_cdns_enable_interrupt(cdns, false); - return ret; }
void intel_check_clock_stop(struct sdw_intel *sdw) @@ -158,16 +154,15 @@ int intel_start_bus_after_clock_stop(struct sdw_intel *sdw) struct sdw_cdns *cdns = &sdw->cdns; int ret;
- ret = sdw_cdns_enable_interrupt(cdns, true); - if (ret < 0) { - dev_err(dev, "%s: cannot enable interrupts: %d\n", __func__, ret); - return ret; - } - ret = sdw_cdns_clock_restart(cdns, false); if (ret < 0) { dev_err(dev, "%s: unable to restart clock: %d\n", __func__, ret); - sdw_cdns_enable_interrupt(cdns, false); + return ret; + } + + ret = sdw_cdns_enable_interrupt(cdns, true); + if (ret < 0) { + dev_err(dev, "%s: cannot enable interrupts: %d\n", __func__, ret); return ret; }
From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
Combining hardware reset with the multi-link mode leads to a shortened hardware reset pattern observed on the bus.
The updated hardware programming sequence is to first enable the clock with the sync_arm/sync_go pattern, and only in a second step to issue the hardware reset sequence. Since there is no longer a dependency between sync_arm/sync_go and hw_reset, the behavior of sdw_cdns_exit_reset() is changed to wait for the self-clearing CONFIG_UPDATE to go back to zero,
Link: https://github.com/thesofproject/linux/issues/4170 Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/cadence_master.c | 31 ++++++++++++++++++------ drivers/soundwire/cadence_master.h | 3 +++ drivers/soundwire/intel_bus_common.c | 36 ++++++++++++++++++++-------- 3 files changed, 53 insertions(+), 17 deletions(-)
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 39502bc75712..58686ae50bbf 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -283,6 +283,29 @@ static int cdns_config_update(struct sdw_cdns *cdns) return ret; }
+/** + * sdw_cdns_config_update() - Update configurations + * @cdns: Cadence instance + */ +void sdw_cdns_config_update(struct sdw_cdns *cdns) +{ + /* commit changes */ + cdns_writel(cdns, CDNS_MCP_CONFIG_UPDATE, CDNS_MCP_CONFIG_UPDATE_BIT); +} +EXPORT_SYMBOL(sdw_cdns_config_update); + +/** + * sdw_cdns_config_update_set_wait() - wait until configuration update bit is self-cleared + * @cdns: Cadence instance + */ +int sdw_cdns_config_update_set_wait(struct sdw_cdns *cdns) +{ + /* the hardware recommendation is to wait at least 300us */ + return cdns_set_wait(cdns, CDNS_MCP_CONFIG_UPDATE, + CDNS_MCP_CONFIG_UPDATE_BIT, 0); +} +EXPORT_SYMBOL(sdw_cdns_config_update_set_wait); + /* * debugfs */ @@ -1116,13 +1139,7 @@ int sdw_cdns_exit_reset(struct sdw_cdns *cdns) CDNS_MCP_CONTROL_HW_RST);
/* commit changes */ - cdns_updatel(cdns, CDNS_MCP_CONFIG_UPDATE, - CDNS_MCP_CONFIG_UPDATE_BIT, - CDNS_MCP_CONFIG_UPDATE_BIT); - - /* don't wait here */ - return 0; - + return cdns_config_update(cdns); } EXPORT_SYMBOL(sdw_cdns_exit_reset);
diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h index 27c56274217f..8e328ba01c0a 100644 --- a/drivers/soundwire/cadence_master.h +++ b/drivers/soundwire/cadence_master.h @@ -197,4 +197,7 @@ int cdns_set_sdw_stream(struct snd_soc_dai *dai, void sdw_cdns_check_self_clearing_bits(struct sdw_cdns *cdns, const char *string, bool initial_delay, int reset_iterations);
+void sdw_cdns_config_update(struct sdw_cdns *cdns); +int sdw_cdns_config_update_set_wait(struct sdw_cdns *cdns); + #endif /* __SDW_CADENCE_H */ diff --git a/drivers/soundwire/intel_bus_common.c b/drivers/soundwire/intel_bus_common.c index 901d4f5736c1..be0c93106fc8 100644 --- a/drivers/soundwire/intel_bus_common.c +++ b/drivers/soundwire/intel_bus_common.c @@ -29,11 +29,7 @@ int intel_start_bus(struct sdw_intel *sdw) return ret; }
- ret = sdw_cdns_exit_reset(cdns); - if (ret < 0) { - dev_err(dev, "%s: unable to exit bus reset sequence: %d\n", __func__, ret); - return ret; - } + sdw_cdns_config_update(cdns);
if (bus->multi_link) { ret = sdw_intel_sync_go(sdw); @@ -43,6 +39,18 @@ int intel_start_bus(struct sdw_intel *sdw) } }
+ ret = sdw_cdns_config_update_set_wait(cdns); + if (ret < 0) { + dev_err(dev, "%s: CONFIG_UPDATE BIT still set\n", __func__); + return ret; + } + + ret = sdw_cdns_exit_reset(cdns); + if (ret < 0) { + dev_err(dev, "%s: unable to exit bus reset sequence: %d\n", __func__, ret); + return ret; + } + ret = sdw_cdns_enable_interrupt(cdns, true); if (ret < 0) { dev_err(dev, "%s: cannot enable interrupts: %d\n", __func__, ret); @@ -112,11 +120,7 @@ int intel_start_bus_after_reset(struct sdw_intel *sdw) }
if (!clock_stop0) { - ret = sdw_cdns_exit_reset(cdns); - if (ret < 0) { - dev_err(dev, "unable to exit bus reset sequence during resume\n"); - return ret; - } + sdw_cdns_config_update(cdns);
if (bus->multi_link) { ret = sdw_intel_sync_go(sdw); @@ -126,6 +130,18 @@ int intel_start_bus_after_reset(struct sdw_intel *sdw) } }
+ ret = sdw_cdns_config_update_set_wait(cdns); + if (ret < 0) { + dev_err(dev, "%s: CONFIG_UPDATE BIT still set\n", __func__); + return ret; + } + + ret = sdw_cdns_exit_reset(cdns); + if (ret < 0) { + dev_err(dev, "unable to exit bus reset sequence during resume\n"); + return ret; + } + ret = sdw_cdns_enable_interrupt(cdns, true); if (ret < 0) { dev_err(dev, "cannot enable interrupts during resume\n");
From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
We want to wait for the CONFIG_UPDATE bit to clear before doing something else.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/cadence_master.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 58686ae50bbf..0efc1c3bee5f 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -456,9 +456,9 @@ static int cdns_parity_error_injection(void *data, u64 value) CDNS_IP_MCP_CMDCTRL_INSERT_PARITY_ERR);
/* commit changes */ - cdns_updatel(cdns, CDNS_MCP_CONFIG_UPDATE, - CDNS_MCP_CONFIG_UPDATE_BIT, - CDNS_MCP_CONFIG_UPDATE_BIT); + ret = cdns_clear_bit(cdns, CDNS_MCP_CONFIG_UPDATE, CDNS_MCP_CONFIG_UPDATE_BIT); + if (ret < 0) + goto unlock;
/* do a broadcast dummy read to avoid bus clashes */ ret = sdw_bread_no_pm_unlocked(&cdns->bus, 0xf, SDW_SCP_DEVID_0); @@ -470,16 +470,17 @@ static int cdns_parity_error_injection(void *data, u64 value) 0);
/* commit changes */ - cdns_updatel(cdns, CDNS_MCP_CONFIG_UPDATE, - CDNS_MCP_CONFIG_UPDATE_BIT, - CDNS_MCP_CONFIG_UPDATE_BIT); + ret = cdns_clear_bit(cdns, CDNS_MCP_CONFIG_UPDATE, CDNS_MCP_CONFIG_UPDATE_BIT); + if (ret < 0) + goto unlock;
+ /* Userspace changed the hardware state behind the kernel's back */ + add_taint(TAINT_USER, LOCKDEP_STILL_OK); + +unlock: /* Continue bus operation with parity error injection disabled */ mutex_unlock(&bus->bus_lock);
- /* Userspace changed the hardware state behind the kernel's back */ - add_taint(TAINT_USER, LOCKDEP_STILL_OK); - /* * allow Master device to enter pm_runtime suspend. This may * also result in Slave devices suspending.
participants (2)
-
Bard Liao -
Vinod Koul