From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

Existing devices and implementations only support the required CLOCK_STOP_MODE0. All the code related to CLOCK_STOP_MODE1 has not been tested and is highly questionable, with a clear confusion between CLOCK_STOP_MODE1 and the simple clock stop state machine.

This patch removes all usages of CLOCK_STOP_MODE1 - which has no impact on any solution - and fixes the use of the simple clock stop state machine. The resulting code should be a lot more symmetrical and easier to maintain.

Note that CLOCK_STOP_MODE1 is not supported in the SoundWire Device Class specification so it's rather unlikely that we need to re-add this mode later.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Guennadi Liakhovetski guennadi.liakhovetski@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/bus.c | 100 ++++++++++++++-------------------- include/linux/soundwire/sdw.h | 2 - 2 files changed, 40 insertions(+), 62 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index a9e0aa72654d..dc4033b6f2e9 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -821,26 +821,6 @@ static void sdw_modify_slave_status(struct sdw_slave *slave, mutex_unlock(&bus->bus_lock); }

-static enum sdw_clk_stop_mode sdw_get_clk_stop_mode(struct sdw_slave *slave) -{ - enum sdw_clk_stop_mode mode; - - /* - * Query for clock stop mode if Slave implements - * ops->get_clk_stop_mode, else read from property. - */ - if (slave->ops && slave->ops->get_clk_stop_mode) { - mode = slave->ops->get_clk_stop_mode(slave); - } else { - if (slave->prop.clk_stop_mode1) - mode = SDW_CLK_STOP_MODE1; - else - mode = SDW_CLK_STOP_MODE0; - } - - return mode; -} - static int sdw_slave_clk_stop_callback(struct sdw_slave *slave, enum sdw_clk_stop_mode mode, enum sdw_clk_stop_type type) @@ -933,7 +913,6 @@ static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num) */ int sdw_bus_prep_clk_stop(struct sdw_bus *bus) { - enum sdw_clk_stop_mode slave_mode; bool simple_clk_stop = true; struct sdw_slave *slave; bool is_slave = false; @@ -955,10 +934,8 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus) /* Identify if Slave(s) are available on Bus */ is_slave = true;

- slave_mode = sdw_get_clk_stop_mode(slave); - slave->curr_clk_stop_mode = slave_mode; - - ret = sdw_slave_clk_stop_callback(slave, slave_mode, + ret = sdw_slave_clk_stop_callback(slave, + SDW_CLK_STOP_MODE0, SDW_CLK_PRE_PREPARE); if (ret < 0) { dev_err(&slave->dev, @@ -966,22 +943,29 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus) return ret; }

- ret = sdw_slave_clk_stop_prepare(slave, - slave_mode, true); - if (ret < 0) { - dev_err(&slave->dev, - "pre-prepare failed:%d", ret); - return ret; - } - - if (slave_mode == SDW_CLK_STOP_MODE1) + /* Only prepare a Slave device if needed */ + if (!slave->prop.simple_clk_stop_capable) { simple_clk_stop = false; + + ret = sdw_slave_clk_stop_prepare(slave, + SDW_CLK_STOP_MODE0, + true); + if (ret < 0) { + dev_err(&slave->dev, + "pre-prepare failed:%d", ret); + return ret; + } + } }

/* Skip remaining clock stop preparation if no Slave is attached */ if (!is_slave) return ret;

+ /* + * Don't wait for all Slaves to be ready if they follow the simple + * state machine + */ if (!simple_clk_stop) { ret = sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM); @@ -998,17 +982,13 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus) slave->status != SDW_SLAVE_ALERT) continue;

- slave_mode = slave->curr_clk_stop_mode; + ret = sdw_slave_clk_stop_callback(slave, + SDW_CLK_STOP_MODE0, + SDW_CLK_POST_PREPARE);

- if (slave_mode == SDW_CLK_STOP_MODE1) { - ret = sdw_slave_clk_stop_callback(slave, - slave_mode, - SDW_CLK_POST_PREPARE); - - if (ret < 0) { - dev_err(&slave->dev, - "post-prepare failed:%d", ret); - } + if (ret < 0) { + dev_err(&slave->dev, + "post-prepare failed:%d", ret); } }

@@ -1059,7 +1039,6 @@ EXPORT_SYMBOL(sdw_bus_clk_stop); */ int sdw_bus_exit_clk_stop(struct sdw_bus *bus) { - enum sdw_clk_stop_mode mode; bool simple_clk_stop = true; struct sdw_slave *slave; bool is_slave = false; @@ -1081,31 +1060,33 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus) /* Identify if Slave(s) are available on Bus */ is_slave = true;

- mode = slave->curr_clk_stop_mode; - - if (mode == SDW_CLK_STOP_MODE1) { - simple_clk_stop = false; - continue; - } - - ret = sdw_slave_clk_stop_callback(slave, mode, + ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0, SDW_CLK_PRE_DEPREPARE); if (ret < 0) dev_warn(&slave->dev, "clk stop deprep failed:%d", ret);

- ret = sdw_slave_clk_stop_prepare(slave, mode, - false); + /* Only de-prepare a Slave device if needed */ + if (!slave->prop.simple_clk_stop_capable) { + simple_clk_stop = false;

- if (ret < 0) - dev_warn(&slave->dev, - "clk stop deprep failed:%d", ret); + ret = sdw_slave_clk_stop_prepare(slave, SDW_CLK_STOP_MODE0, + false); + + if (ret < 0) + dev_warn(&slave->dev, + "clk stop deprep failed:%d", ret); + } }

/* Skip remaining clock stop de-preparation if no Slave is attached */ if (!is_slave) return 0;

+ /* + * Don't wait for all Slaves to be ready if they follow the simple + * state machine + */ if (!simple_clk_stop) sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);

@@ -1117,8 +1098,7 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus) slave->status != SDW_SLAVE_ALERT) continue;

- mode = slave->curr_clk_stop_mode; - sdw_slave_clk_stop_callback(slave, mode, + sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0, SDW_CLK_POST_DEPREPARE); }

diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index ced07f8fde87..5d93d9949653 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -624,7 +624,6 @@ struct sdw_slave_ops { int (*port_prep)(struct sdw_slave *slave, struct sdw_prepare_ch *prepare_ch, enum sdw_port_prep_ops pre_ops); - int (*get_clk_stop_mode)(struct sdw_slave *slave); int (*clk_stop)(struct sdw_slave *slave, enum sdw_clk_stop_mode mode, enum sdw_clk_stop_type type); @@ -675,7 +674,6 @@ struct sdw_slave { struct list_head node; struct completion port_ready[SDW_MAX_PORTS]; unsigned int m_port_map[SDW_MAX_PORTS]; - enum sdw_clk_stop_mode curr_clk_stop_mode; u16 dev_num; u16 dev_num_sticky; bool probed;

From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com

If a device lost sync and can no longer ACK a command, it may not be able to enter a lower-power state but it will still be able to resync when the clock restarts. In those cases, we want to continue with the clock stop sequence.

This patch modifies the behavior during clock stop sequences to only log errors unrelated to -ENODATA/Command_Ignored. The flow is also modified so that loops continue to prepare/deprepare other devices even when one seems to have lost sync.

When resuming the clocks, all issues are logged with a dev_warn(), previously only some of them were checked. This is the only part that now differs between the clock stop entry and clock stop exit sequences: while we don't want to stop the suspend flow, we do want information on potential issues while resuming, as they may have ripple effects.

For consistency the log messages are also modified to be unique and self-explanatory. Errors in sdw_slave_clk_stop_callback() were removed, they are now handled in the caller.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Guennadi Liakhovetski guennadi.liakhovetski@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/bus.c | 69 +++++++++++++++++++++-------------------- 1 file changed, 36 insertions(+), 33 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index dc4033b6f2e9..100d904bf700 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -829,11 +829,8 @@ static int sdw_slave_clk_stop_callback(struct sdw_slave *slave,

if (slave->ops && slave->ops->clk_stop) { ret = slave->ops->clk_stop(slave, mode, type); - if (ret < 0) { - dev_err(&slave->dev, - "Clk Stop type =%d failed: %d\n", type, ret); + if (ret < 0) return ret; - } }

return 0; @@ -860,7 +857,8 @@ static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave, } else { ret = sdw_read_no_pm(slave, SDW_SCP_SYSTEMCTRL); if (ret < 0) { - dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL read failed:%d\n", ret); + if (ret != -ENODATA) + dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL read failed:%d\n", ret); return ret; } val = ret; @@ -869,9 +867,8 @@ static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,

ret = sdw_write_no_pm(slave, SDW_SCP_SYSTEMCTRL, val);

- if (ret < 0) - dev_err(&slave->dev, - "Clock Stop prepare failed for slave: %d", ret); + if (ret < 0 && ret != -ENODATA) + dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL write failed:%d\n", ret);

return ret; } @@ -922,6 +919,9 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus) * In order to save on transition time, prepare * each Slave and then wait for all Slave(s) to be * prepared for clock stop. + * If one of the Slave devices has lost sync and + * replies with Command Ignored/-ENODATA, we continue + * the loop */ list_for_each_entry(slave, &bus->slaves, node) { if (!slave->dev_num) @@ -937,9 +937,8 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus) ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0, SDW_CLK_PRE_PREPARE); - if (ret < 0) { - dev_err(&slave->dev, - "pre-prepare failed:%d", ret); + if (ret < 0 && ret != -ENODATA) { + dev_err(&slave->dev, "clock stop pre-prepare cb failed:%d\n", ret); return ret; }

@@ -950,9 +949,8 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus) ret = sdw_slave_clk_stop_prepare(slave, SDW_CLK_STOP_MODE0, true); - if (ret < 0) { - dev_err(&slave->dev, - "pre-prepare failed:%d", ret); + if (ret < 0 && ret != -ENODATA) { + dev_err(&slave->dev, "clock stop prepare failed:%d\n", ret); return ret; } } @@ -960,7 +958,7 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus)

/* Skip remaining clock stop preparation if no Slave is attached */ if (!is_slave) - return ret; + return 0;

/* * Don't wait for all Slaves to be ready if they follow the simple @@ -969,6 +967,12 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus) if (!simple_clk_stop) { ret = sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM); + /* + * if there are no Slave devices present and the reply is + * Command_Ignored/-ENODATA, we don't need to continue with the + * flow and can just return here. The error code is not modified + * and its handling left as an exercise for the caller. + */ if (ret < 0) return ret; } @@ -986,13 +990,13 @@ int sdw_bus_prep_clk_stop(struct sdw_bus *bus) SDW_CLK_STOP_MODE0, SDW_CLK_POST_PREPARE);

- if (ret < 0) { - dev_err(&slave->dev, - "post-prepare failed:%d", ret); + if (ret < 0 && ret != -ENODATA) { + dev_err(&slave->dev, "clock stop post-prepare cb failed:%d\n", ret); + return ret; } }

- return ret; + return 0; } EXPORT_SYMBOL(sdw_bus_prep_clk_stop);

@@ -1015,12 +1019,8 @@ int sdw_bus_clk_stop(struct sdw_bus *bus) ret = sdw_bwrite_no_pm(bus, SDW_BROADCAST_DEV_NUM, SDW_SCP_CTRL, SDW_SCP_CTRL_CLK_STP_NOW); if (ret < 0) { - if (ret == -ENODATA) - dev_dbg(bus->dev, - "ClockStopNow Broadcast msg ignored %d", ret); - else - dev_err(bus->dev, - "ClockStopNow Broadcast msg failed %d", ret); + if (ret != -ENODATA) + dev_err(bus->dev, "ClockStopNow Broadcast msg failed %d\n", ret); return ret; }

@@ -1063,8 +1063,7 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus) ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0, SDW_CLK_PRE_DEPREPARE); if (ret < 0) - dev_warn(&slave->dev, - "clk stop deprep failed:%d", ret); + dev_warn(&slave->dev, "clock stop pre-deprepare cb failed:%d\n", ret);

/* Only de-prepare a Slave device if needed */ if (!slave->prop.simple_clk_stop_capable) { @@ -1074,8 +1073,7 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus) false);

if (ret < 0) - dev_warn(&slave->dev, - "clk stop deprep failed:%d", ret); + dev_warn(&slave->dev, "clock stop deprepare failed:%d\n", ret); } }

@@ -1087,8 +1085,11 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus) * Don't wait for all Slaves to be ready if they follow the simple * state machine */ - if (!simple_clk_stop) - sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM); + if (!simple_clk_stop) { + ret = sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM); + if (ret < 0) + dev_warn(&slave->dev, "clock stop deprepare wait failed:%d\n", ret); + }

list_for_each_entry(slave, &bus->slaves, node) { if (!slave->dev_num) @@ -1098,8 +1099,10 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus) slave->status != SDW_SLAVE_ALERT) continue;

- sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0, - SDW_CLK_POST_DEPREPARE); + ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0, + SDW_CLK_POST_DEPREPARE); + if (ret < 0) + dev_warn(&slave->dev, "clock stop post-deprepare cb failed:%d\n", ret); }

return 0;