From: Bard Liao yung-chuan.liao@linux.intel.com

The existing code uses one pair of interrupt handler/thread per link but at the hardware level the interrupt is shared. This works fine for legacy PCI interrupts, but leads to timeouts in MSI (Message-Signaled Interrupt) mode, likely due to edges being lost.

This patch unifies interrupt handling for all links with a single threaded IRQ handler. The handler is simplified to the bare minimum of detecting a SoundWire interrupt, and the thread takes care of dealing with interrupt sources. This partition follows the model used for the SOF IPC on HDaudio platforms, where similar timeout issues were noticed and doing all the interrupt handling/clearing in the thread improved reliability/stability.

Validation results with 4 links active in parallel show a night-and-day improvement with no timeouts noticed even during stress tests. Latency and quality of service are not affected by the change - mostly because events on a SoundWire link are throttled by the bus frame rate (typically 8..48kHz).

Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 17 ++++++----- drivers/soundwire/cadence_master.h | 4 +++ drivers/soundwire/intel.c | 17 +---------- drivers/soundwire/intel.h | 2 ++ drivers/soundwire/intel_init.c | 45 ++++++++++++++++++++++++++++- include/linux/soundwire/sdw_intel.h | 2 ++ 6 files changed, 62 insertions(+), 25 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index fed21e2b2277..362fb6e49bfe 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -17,6 +17,7 @@ #include <linux/soundwire/sdw.h> #include <sound/pcm_params.h> #include <sound/soc.h> +#include <linux/workqueue.h> #include "bus.h" #include "cadence_master.h"

@@ -745,7 +746,7 @@ irqreturn_t sdw_cdns_irq(int irq, void *dev_id) CDNS_MCP_INT_SLAVE_MASK, 0);

int_status &= ~CDNS_MCP_INT_SLAVE_MASK; - ret = IRQ_WAKE_THREAD; + schedule_work(&cdns->work); }

cdns_writel(cdns, CDNS_MCP_INTSTAT, int_status); @@ -754,13 +755,14 @@ irqreturn_t sdw_cdns_irq(int irq, void *dev_id) EXPORT_SYMBOL(sdw_cdns_irq);

/** - * sdw_cdns_thread() - Cadence irq thread handler - * @irq: irq number - * @dev_id: irq context + * To update slave status in a work since we will need to handle + * other interrupts eg. CDNS_MCP_INT_RX_WL during the update slave + * process. */ -irqreturn_t sdw_cdns_thread(int irq, void *dev_id) +static void cdns_update_slave_status_work(struct work_struct *work) { - struct sdw_cdns *cdns = dev_id; + struct sdw_cdns *cdns = + container_of(work, struct sdw_cdns, work); u32 slave0, slave1;

dev_dbg_ratelimited(cdns->dev, "Slave status change\n"); @@ -777,9 +779,7 @@ irqreturn_t sdw_cdns_thread(int irq, void *dev_id) cdns_updatel(cdns, CDNS_MCP_INTMASK, CDNS_MCP_INT_SLAVE_MASK, CDNS_MCP_INT_SLAVE_MASK);

- return IRQ_HANDLED; } -EXPORT_SYMBOL(sdw_cdns_thread);

/* * init routines @@ -1187,6 +1187,7 @@ int sdw_cdns_probe(struct sdw_cdns *cdns) init_completion(&cdns->tx_complete); cdns->bus.port_ops = &cdns_port_ops;

+ INIT_WORK(&cdns->work, cdns_update_slave_status_work); return 0; } EXPORT_SYMBOL(sdw_cdns_probe); diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h index 001457cbe5ad..0f108fd31fd9 100644 --- a/drivers/soundwire/cadence_master.h +++ b/drivers/soundwire/cadence_master.h @@ -126,6 +126,10 @@ struct sdw_cdns {

bool link_up; unsigned int msg_count; + + struct work_struct work; + + struct list_head list; };

#define bus_to_cdns(_bus) container_of(_bus, struct sdw_cdns, bus) diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index cad1c0b64ee3..c918a26d0772 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -1095,6 +1095,7 @@ static int intel_master_probe(struct sdw_master_device *md, void *link_ctx) sdw->cdns.msg_count = 0; sdw->cdns.bus.dev = &md->dev; sdw->cdns.bus.link_id = md->link_id; + sdw->link_res->cdns = &sdw->cdns;

sdw_cdns_probe(&sdw->cdns);

@@ -1119,21 +1120,7 @@ static int intel_master_probe(struct sdw_master_device *md, void *link_ctx) return 0; }

- /* Acquire IRQ */ - ret = request_threaded_irq(sdw->link_res->irq, - sdw_cdns_irq, sdw_cdns_thread, - IRQF_SHARED, KBUILD_MODNAME, &sdw->cdns); - if (ret < 0) { - dev_err(sdw->cdns.dev, "unable to grab IRQ %d, disabling device\n", - sdw->link_res->irq); - goto err_init; - } - return 0; - -err_init: - sdw_delete_bus_master(&sdw->cdns.bus); - return ret; }

static int intel_master_startup(struct sdw_master_device *md) @@ -1190,7 +1177,6 @@ static int intel_master_startup(struct sdw_master_device *md) err_interrupt: sdw_cdns_enable_interrupt(&sdw->cdns, false); err_init: - free_irq(sdw->link_res->irq, sdw); sdw_delete_bus_master(&sdw->cdns.bus); return ret; } @@ -1204,7 +1190,6 @@ static int intel_master_remove(struct sdw_master_device *md) if (!sdw->cdns.bus.prop.hw_disabled) { intel_debugfs_exit(sdw); sdw_cdns_enable_interrupt(&sdw->cdns, false); - free_irq(sdw->link_res->irq, sdw); snd_soc_unregister_component(sdw->cdns.dev); } sdw_delete_bus_master(&sdw->cdns.bus); diff --git a/drivers/soundwire/intel.h b/drivers/soundwire/intel.h index cfab2f00214d..2ae4fa748686 100644 --- a/drivers/soundwire/intel.h +++ b/drivers/soundwire/intel.h @@ -25,6 +25,8 @@ struct sdw_intel_link_res { int irq; const struct sdw_intel_ops *ops; struct device *dev; + struct sdw_cdns *cdns; + struct list_head list; };

#define SDW_INTEL_QUIRK_MASK_BUS_DISABLE BIT(1) diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c index 14ffe9ce2929..ed2a83989c72 100644 --- a/drivers/soundwire/intel_init.c +++ b/drivers/soundwire/intel_init.c @@ -11,8 +11,10 @@ #include <linux/export.h> #include <linux/io.h> #include <linux/module.h> +#include <linux/interrupt.h> #include <linux/soundwire/sdw.h> #include <linux/soundwire/sdw_intel.h> +#include "cadence_master.h" #include "intel.h"

#define SDW_LINK_TYPE 4 /* from Intel ACPI documentation */ @@ -161,6 +163,32 @@ void sdw_intel_enable_irq(void __iomem *mmio_base, bool enable) } EXPORT_SYMBOL(sdw_intel_enable_irq);

+static irqreturn_t sdw_intel_irq(int irq, void *dev_id) +{ + struct sdw_intel_ctx *ctx = dev_id; + u32 int_status; + + int_status = readl(ctx->mmio_base + HDA_DSP_REG_ADSPIS2); + if (int_status & HDA_DSP_REG_ADSPIC2_SNDW) { + sdw_intel_enable_irq(ctx->mmio_base, false); + return IRQ_WAKE_THREAD; + } + + return IRQ_NONE; +} + +static irqreturn_t sdw_intel_thread(int irq, void *dev_id) +{ + struct sdw_intel_ctx *ctx = dev_id; + struct sdw_intel_link_res *link; + + list_for_each_entry(link, &ctx->link_list, list) + sdw_cdns_irq(irq, link->cdns); + + sdw_intel_enable_irq(ctx->mmio_base, true); + return IRQ_HANDLED; +} + static struct sdw_intel_ctx *sdw_intel_probe_controller(struct sdw_intel_res *res) { @@ -171,6 +199,7 @@ static struct sdw_intel_ctx u32 link_mask; int count; int i; + int ret;

if (!res) return NULL; @@ -196,10 +225,13 @@ static struct sdw_intel_ctx ctx->mmio_base = res->mmio_base; ctx->link_mask = res->link_mask; ctx->handle = res->handle; + ctx->irq = res->irq;

link = ctx->links; link_mask = ctx->link_mask;

+ INIT_LIST_HEAD(&ctx->link_list); + /* Create SDW Master devices */ for (i = 0; i < count; i++, link++) { if (link_mask && !(link_mask & BIT(i))) @@ -220,12 +252,22 @@ static struct sdw_intel_ctx + (SDW_LINK_SIZE * i); link->shim = res->mmio_base + SDW_SHIM_BASE; link->alh = res->mmio_base + SDW_ALH_BASE; - link->irq = res->irq; link->ops = res->ops; link->dev = res->dev;

/* let the SoundWire master driver to its probe */ md->driver->probe(md, link); + + list_add_tail(&link->list, &ctx->link_list); + } + + ret = request_threaded_irq(ctx->irq, + sdw_intel_irq, sdw_intel_thread, + IRQF_SHARED, KBUILD_MODNAME, ctx); + if (ret < 0) { + dev_err(&adev->dev, "unable to grab IRQ %d, disabling device\n", + res->irq); + goto err; }

return ctx; @@ -373,6 +415,7 @@ EXPORT_SYMBOL(sdw_intel_startup); */ void sdw_intel_exit(struct sdw_intel_ctx *ctx) { + free_irq(ctx->irq, ctx); sdw_intel_cleanup(ctx); kfree(ctx); } diff --git a/include/linux/soundwire/sdw_intel.h b/include/linux/soundwire/sdw_intel.h index 36e2b522a749..373947003cea 100644 --- a/include/linux/soundwire/sdw_intel.h +++ b/include/linux/soundwire/sdw_intel.h @@ -94,7 +94,9 @@ struct sdw_intel_ctx { void __iomem *mmio_base; u32 link_mask; acpi_handle handle; + int irq; struct sdw_intel_link_res *links; + struct list_head link_list; };

/*

Add support for pm_runtime with the appropriate error checks for sdw_write/read functions, e.g. when pm_runtime is not supported.

Also expose internal functions without pm_runtime support, which are required to perform any sort of suspend/resume operation, as well as any enumeration tasks.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/bus.c | 68 +++++++++++++++++++++++++++++++---------- 1 file changed, 52 insertions(+), 16 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 903aee258800..7f431677f152 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -317,6 +317,46 @@ int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave, return 0; }

+/* + * Read/Write IO functions. + * no_pm versions can only be called by the bus, e.g. while enumerating or + * handling suspend-resume sequences. + * all clients need to use the pm versions + */ + +static int +sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) +{ + struct sdw_msg msg; + int ret; + + ret = sdw_fill_msg(&msg, slave, addr, count, + slave->dev_num, SDW_MSG_FLAG_READ, val); + if (ret < 0) + return ret; + + return sdw_transfer(slave->bus, &msg); +} + +static int +sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) +{ + struct sdw_msg msg; + int ret; + + ret = sdw_fill_msg(&msg, slave, addr, count, + slave->dev_num, SDW_MSG_FLAG_WRITE, val); + if (ret < 0) + return ret; + + return sdw_transfer(slave->bus, &msg); +} + +int sdw_write_no_pm(struct sdw_slave *slave, u32 addr, u8 value) +{ + return sdw_nwrite_no_pm(slave, addr, 1, &value); +} + /** * sdw_nread() - Read "n" contiguous SDW Slave registers * @slave: SDW Slave @@ -326,19 +366,17 @@ int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave, */ int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) { - struct sdw_msg msg; int ret;

- ret = sdw_fill_msg(&msg, slave, addr, count, - slave->dev_num, SDW_MSG_FLAG_READ, val); - if (ret < 0) - return ret; - ret = pm_runtime_get_sync(slave->bus->dev); - if (ret < 0) + if (ret < 0 && ret != -EACCES) { + pm_runtime_put_noidle(slave->bus->dev); return ret; + } + + ret = sdw_nread_no_pm(slave, addr, count, val);

- ret = sdw_transfer(slave->bus, &msg); + pm_runtime_mark_last_busy(slave->bus->dev); pm_runtime_put(slave->bus->dev);

return ret; @@ -354,19 +392,17 @@ EXPORT_SYMBOL(sdw_nread); */ int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) { - struct sdw_msg msg; int ret;

- ret = sdw_fill_msg(&msg, slave, addr, count, - slave->dev_num, SDW_MSG_FLAG_WRITE, val); - if (ret < 0) - return ret; - ret = pm_runtime_get_sync(slave->bus->dev); - if (ret < 0) + if (ret < 0 && ret != -EACCES) { + pm_runtime_put_noidle(slave->bus->dev); return ret; + } + + ret = sdw_nwrite_no_pm(slave, addr, count, val);

- ret = sdw_transfer(slave->bus, &msg); + pm_runtime_mark_last_busy(slave->bus->dev); pm_runtime_put(slave->bus->dev);

return ret;

These routines are required for power management

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/intel.c | 53 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index c918a26d0772..fe3a8b3b2c04 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -362,6 +362,59 @@ static int intel_shim_init(struct sdw_intel *sdw) return ret; }

+static void intel_shim_wake(struct sdw_intel *sdw, bool wake_enable) +{ + void __iomem *shim = sdw->link_res->shim; + unsigned int link_id = sdw->instance; + u16 wake_en, wake_sts; + + if (wake_enable) { + /* Enable the wakeup */ + intel_writew(shim, SDW_SHIM_WAKEEN, + (SDW_SHIM_WAKEEN_ENABLE << link_id)); + } else { + /* Disable the wake up interrupt */ + wake_en = intel_readw(shim, SDW_SHIM_WAKEEN); + wake_en &= ~(SDW_SHIM_WAKEEN_ENABLE << link_id); + intel_writew(shim, SDW_SHIM_WAKEEN, wake_en); + + /* Clear wake status */ + wake_sts = intel_readw(shim, SDW_SHIM_WAKESTS); + wake_sts |= (SDW_SHIM_WAKEEN_ENABLE << link_id); + intel_writew(shim, SDW_SHIM_WAKESTS_STATUS, wake_sts); + } +} + +static int intel_link_power_down(struct sdw_intel *sdw) +{ + int link_control, spa_mask, cpa_mask, ret; + unsigned int link_id = sdw->instance; + void __iomem *shim = sdw->link_res->shim; + u16 ioctl; + + /* Glue logic */ + ioctl = intel_readw(shim, SDW_SHIM_IOCTL(link_id)); + ioctl |= SDW_SHIM_IOCTL_BKE; + ioctl |= SDW_SHIM_IOCTL_COE; + intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + + ioctl &= ~(SDW_SHIM_IOCTL_MIF); + intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + + /* Link power down sequence */ + link_control = intel_readl(shim, SDW_SHIM_LCTL); + spa_mask = ~(SDW_SHIM_LCTL_SPA << link_id); + cpa_mask = (SDW_SHIM_LCTL_CPA << link_id); + link_control &= spa_mask; + + ret = intel_clear_bit(shim, SDW_SHIM_LCTL, link_control, cpa_mask); + if (ret < 0) + return ret; + + sdw->cdns.link_up = false; + return 0; +} + /* * PDI routines */

Add basic hooks in DAI .startup and .shutdown callbacks.

The SoundWire IP should be powered between those two calls. The power dependencies between SoundWire and DSP are handled with the parent/child relationship, before the SoundWire master device becomes active the parent device will become active and power-up the shared rails.

For now the strategy is to rely on complete enumeration when the device becomes active, so the code is a copy/paste of the sequence for system suspend/resume. In future patches, the strategy will optionally be to rely on clock stop if the enumeration time is prohibitive or when the devices connected to a link can signal a wake.

A module parameter is added to make integration of new Slave devices easier, to e.g. keep the device active or prevent clock-stop.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/intel.c | 108 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 104 insertions(+), 4 deletions(-)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index aeef0c0fc443..650581348732 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -11,6 +11,7 @@ #include <linux/module.h> #include <linux/interrupt.h> #include <linux/io.h> +#include <linux/pm_runtime.h> #include <linux/platform_device.h> #include <sound/pcm_params.h> #include <sound/soc.h> @@ -21,6 +22,20 @@ #include "bus.h" #include "intel.h"

+/* + * debug/config flags for the Intel SoundWire Master. + * + * Since we may have multiple masters active, we can have up to 8 + * flags reused in each byte, with master0 using the ls-byte, etc. + */ + +#define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME BIT(0) +#define SDW_INTEL_MASTER_DISABLE_CLOCK_STOP BIT(1) + +static int md_flags; +module_param_named(sdw_md_flags, md_flags, int, 0444); +MODULE_PARM_DESC(sdw_md_flags, "SoundWire Intel Master device flags (0x0 all off)"); + /* Intel SHIM Registers Definition */ #define SDW_SHIM_LCAP 0x0 #define SDW_SHIM_LCTL 0x4 @@ -742,10 +757,16 @@ static int sdw_stream_setup(struct snd_pcm_substream *substream, static int intel_startup(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) { - /* - * TODO: add pm_runtime support here, the startup callback - * will make sure the IP is 'active' - */ + struct sdw_cdns *cdns = snd_soc_dai_get_drvdata(dai); + int ret; + + ret = pm_runtime_get_sync(cdns->dev); + if (ret < 0 && ret != -EACCES) { + dev_err_ratelimited(cdns->dev, + "pm_runtime_get_sync failed in %s, ret %d\n", + __func__, ret); + pm_runtime_put_noidle(cdns->dev); + }

return sdw_stream_setup(substream, dai); } @@ -924,6 +945,7 @@ static void intel_shutdown(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) { struct sdw_cdns_dma_data *dma; + struct sdw_cdns *cdns = snd_soc_dai_get_drvdata(dai);

dma = snd_soc_dai_get_dma_data(dai, substream); if (!dma) @@ -931,6 +953,9 @@ static void intel_shutdown(struct snd_pcm_substream *substream,

snd_soc_dai_set_dma_data(dai, substream, NULL); kfree(dma); + + pm_runtime_mark_last_busy(cdns->dev); + pm_runtime_put_autosuspend(cdns->dev); }

static int intel_pcm_set_sdw_stream(struct snd_soc_dai *dai, @@ -1180,6 +1205,7 @@ static int intel_master_startup(struct sdw_master_device *md) { struct sdw_cdns_stream_config config; struct sdw_intel *sdw; + int link_flags; int ret;

sdw = md->pdata; @@ -1225,6 +1251,17 @@ static int intel_master_startup(struct sdw_master_device *md)

intel_debugfs_init(sdw);

+ /* Enable runtime PM */ + link_flags = md_flags >> (sdw->cdns.bus.link_id * 8); + if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME)) { + pm_runtime_set_autosuspend_delay(&md->dev, 3000); + pm_runtime_use_autosuspend(&md->dev); + pm_runtime_mark_last_busy(&md->dev); + + pm_runtime_set_active(&md->dev); + pm_runtime_enable(&md->dev); + } + return 0;

err_interrupt: @@ -1288,6 +1325,35 @@ static int intel_suspend(struct device *dev) return 0; }

+static int intel_suspend_runtime(struct device *dev) +{ + struct sdw_cdns *cdns = dev_get_drvdata(dev); + struct sdw_intel *sdw = cdns_to_intel(cdns); + int ret; + + if (cdns->bus.prop.hw_disabled) { + dev_dbg(dev, "SoundWire master %d is disabled, ignoring\n", + cdns->bus.link_id); + return 0; + } + + ret = sdw_cdns_enable_interrupt(cdns, false); + if (ret < 0) { + dev_err(dev, "cannot disable interrupts on suspend\n"); + return ret; + } + + ret = intel_link_power_down(sdw); + if (ret) { + dev_err(dev, "Link power down failed: %d", ret); + return ret; + } + + intel_shim_wake(sdw, false); + + return 0; +} + static int intel_resume(struct device *dev) { struct sdw_cdns *cdns = dev_get_drvdata(dev); @@ -1321,10 +1387,44 @@ static int intel_resume(struct device *dev) return ret; }

+static int intel_resume_runtime(struct device *dev) +{ + struct sdw_cdns *cdns = dev_get_drvdata(dev); + struct sdw_intel *sdw = cdns_to_intel(cdns); + int ret; + + if (cdns->bus.prop.hw_disabled) { + dev_dbg(dev, "SoundWire master %d is disabled, ignoring\n", + cdns->bus.link_id); + return 0; + } + + ret = intel_init(sdw); + if (ret) { + dev_err(dev, "%s failed: %d", __func__, ret); + return ret; + } + + ret = sdw_cdns_enable_interrupt(cdns, true); + if (ret < 0) { + dev_err(dev, "cannot enable interrupts during resume\n"); + 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; + } + + return ret; +} + #endif

static const struct dev_pm_ops intel_pm = { SET_SYSTEM_SLEEP_PM_OPS(intel_suspend, intel_resume) + SET_RUNTIME_PM_OPS(intel_suspend_runtime, intel_resume_runtime, NULL) };

struct sdw_md_driver intel_sdw_driver = {

When resuming, we need to re-enumerate and restart from UNATTACHED.

This will help implement a more robust state machine avoiding race conditions on resume.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/bus.c | 24 ++++++++++++++++++++++++ drivers/soundwire/bus.h | 2 ++ 2 files changed, 26 insertions(+)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 0e761efd32f9..17c744c0ff4c 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -1107,3 +1107,27 @@ int sdw_handle_slave_status(struct sdw_bus *bus, return ret; } EXPORT_SYMBOL(sdw_handle_slave_status); + +void sdw_clear_slave_status(struct sdw_bus *bus) +{ + struct sdw_slave *slave; + int i; + + /* Check all non-zero devices */ + for (i = 1; i <= SDW_MAX_DEVICES; i++) { + mutex_lock(&bus->bus_lock); + if (test_bit(i, bus->assigned) == false) { + mutex_unlock(&bus->bus_lock); + continue; + } + mutex_unlock(&bus->bus_lock); + + slave = sdw_get_slave(bus, i); + if (!slave) + continue; + + if (slave->status != SDW_SLAVE_UNATTACHED) + sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED); + } +} +EXPORT_SYMBOL(sdw_clear_slave_status); diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h index acb8d11a4c84..cdbd11292cc3 100644 --- a/drivers/soundwire/bus.h +++ b/drivers/soundwire/bus.h @@ -165,4 +165,6 @@ sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val) return sdw_write(slave, addr, tmp); }

+void sdw_clear_slave_status(struct sdw_bus *bus); + #endif /* __SDW_BUS_H */

Before checking for the presence of Device0, we first need to clean-up the internal state of Slaves that are no longer attached.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/bus.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 17c744c0ff4c..65521c2ed2e1 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -1033,6 +1033,24 @@ int sdw_handle_slave_status(struct sdw_bus *bus, struct sdw_slave *slave; int i, ret = 0;

+ /* first check if any Slaves fell off the bus */ + for (i = 1; i <= SDW_MAX_DEVICES; i++) { + mutex_lock(&bus->bus_lock); + if (test_bit(i, bus->assigned) == false) { + mutex_unlock(&bus->bus_lock); + continue; + } + mutex_unlock(&bus->bus_lock); + + slave = sdw_get_slave(bus, i); + if (!slave) + continue; + + if (status[i] == SDW_SLAVE_UNATTACHED && + slave->status != SDW_SLAVE_UNATTACHED) + sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED); + } + if (status[0] == SDW_SLAVE_ATTACHED) { dev_dbg(bus->dev, "Slave attached, programming device number\n"); ret = sdw_program_device_num(bus);

init_completion() is called when the Slave device becomes unattached, as done with enumeration_complete.

The difference with the enumeration_complete case is that complete() is signaled when the Slave device is fully initialized after the .update_status() callback is called.

A Slave device driver can decide to wait on either of the two complete() cases, depending on its initialization code and requirements.

Signed-off-by: Rander Wang rander.wang@linux.intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/bus.c | 8 ++++++++ drivers/soundwire/slave.c | 1 + 2 files changed, 9 insertions(+)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index b18110726273..93856747b934 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -648,6 +648,7 @@ static void sdw_modify_slave_status(struct sdw_slave *slave, __func__, slave->dev_num);

init_completion(&slave->enumeration_complete); + init_completion(&slave->initialization_complete);

} else if (status == SDW_SLAVE_ATTACHED) { dev_dbg(&slave->dev, @@ -1050,6 +1051,7 @@ int sdw_handle_slave_status(struct sdw_bus *bus, { enum sdw_slave_status prev_status; struct sdw_slave *slave; + bool attached_initializing; int i, ret = 0;

/* first check if any Slaves fell off the bus */ @@ -1095,6 +1097,8 @@ int sdw_handle_slave_status(struct sdw_bus *bus, if (!slave) continue;

+ attached_initializing = false; + switch (status[i]) { case SDW_SLAVE_UNATTACHED: if (slave->status == SDW_SLAVE_UNATTACHED) @@ -1121,6 +1125,8 @@ int sdw_handle_slave_status(struct sdw_bus *bus, if (prev_status == SDW_SLAVE_ALERT) break;

+ attached_initializing = true; + ret = sdw_initialize_slave(slave); if (ret) dev_err(bus->dev, @@ -1139,6 +1145,8 @@ int sdw_handle_slave_status(struct sdw_bus *bus, if (ret) dev_err(slave->bus->dev, "Update Slave status failed:%d\n", ret); + if (attached_initializing) + complete(&slave->initialization_complete); }

return ret; diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c index 5c6c744e0713..543f4ddd9de0 100644 --- a/drivers/soundwire/slave.c +++ b/drivers/soundwire/slave.c @@ -52,6 +52,7 @@ static int sdw_slave_add(struct sdw_bus *bus, slave->bus = bus; slave->status = SDW_SLAVE_UNATTACHED; init_completion(&slave->enumeration_complete); + init_completion(&slave->initialization_complete); slave->dev_num = 0; init_completion(&slave->probe_complete); slave->probed = false;

Before removing the slave device, disable pm_runtime to prevent any race condition with the resume being executed after the bus and slave devices are removed.

Since this pm_runtime_disable() is handled in common routines, implementations of Slave drivers do not need to call it in their .remove() routine.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/bus.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 93856747b934..7d02b0ae68e2 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -113,6 +113,8 @@ static int sdw_delete_slave(struct device *dev, void *data) struct sdw_slave *slave = to_sdw_slave_device(dev); struct sdw_bus *bus = slave->bus;

+ pm_runtime_disable(dev); + sdw_slave_debugfs_exit(slave);

mutex_lock(&bus->bus_lock);

From: Bard Liao yung-chuan.liao@linux.intel.com

We don't need to prepare the stream again if the stream is already prepared.

sdw_prepare_stream() could be called multiple times without calling sdw_deprepare_stream(). We call sdw_prepare_stream() in the prepare dai ops and sdw_deprepare_stream() in the hw_free dai ops. If an xrun happens, sdw_prepare_stream() will be called but sdw_deprepare_stream() will not, which results in an imbalance and an invalid total bandwidth.

Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/stream.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c index 0a074d445b8d..38375c9124e4 100644 --- a/drivers/soundwire/stream.c +++ b/drivers/soundwire/stream.c @@ -1544,7 +1544,7 @@ static int _sdw_prepare_stream(struct sdw_stream_runtime *stream) */ int sdw_prepare_stream(struct sdw_stream_runtime *stream) { - int ret = 0; + int ret;

if (!stream) { pr_err("SoundWire: Handle not found for stream\n"); @@ -1553,6 +1553,11 @@ int sdw_prepare_stream(struct sdw_stream_runtime *stream)

sdw_acquire_bus_lock(stream);

+ if (stream->state == SDW_STREAM_PREPARED) { + ret = 0; + goto state_err; + } + if (stream->state != SDW_STREAM_CONFIGURED && stream->state != SDW_STREAM_DEPREPARED && stream->state != SDW_STREAM_DISABLED) {

From: Bard Liao yung-chuan.liao@linux.intel.com

The .prepare() callback is invoked for normal streaming, underflows or during the system resume transition. In the latter case, the context for the ALH PDIs is lost, and the DSP is not initialized properly either, but the bus parameters don't need to be recomputed.

To avoid keeping track of state variables, it's simpler to just reinitialize the SHIM/ALH/Cadence/DSP settings in .prepare.

Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/intel.c | 40 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index f0f9a6252522..ec6c58635a99 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -117,6 +117,8 @@ struct sdw_intel { struct sdw_cdns cdns; int instance; struct sdw_intel_link_res *link_res; + struct snd_pcm_hw_params *hw_params; + struct sdw_cdns_pdi *pdi; #ifdef CONFIG_DEBUG_FS struct dentry *debugfs; #endif @@ -813,6 +815,8 @@ static int intel_hw_params(struct snd_pcm_substream *substream, intel_pdi_alh_configure(sdw, pdi); sdw_cdns_config_stream(cdns, ch, dir, pdi);

+ sdw->pdi = pdi; + sdw->hw_params = params;

/* Inform DSP about PDI stream number */ ret = intel_params_stream(sdw, substream, dai, params, @@ -856,7 +860,11 @@ static int intel_hw_params(struct snd_pcm_substream *substream, static int intel_prepare(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) { + struct sdw_cdns *cdns = snd_soc_dai_get_drvdata(dai); + struct sdw_intel *sdw = cdns_to_intel(cdns); struct sdw_cdns_dma_data *dma; + int ch, dir; + int ret;

dma = snd_soc_dai_get_dma_data(dai, substream); if (!dma) { @@ -865,7 +873,35 @@ static int intel_prepare(struct snd_pcm_substream *substream, return -EIO; }

- return sdw_prepare_stream(dma->stream); + /* + * .prepare() is called after system resume, where we need to + * reinitialize the SHIM/ALH/Cadence IP. To avoid dealing with + * complicated state machines, we just re-initialize in all + * cases since there are no side effects. + */ + + /* configure stream */ + ch = params_channels(sdw->hw_params); + if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) + dir = SDW_DATA_DIR_RX; + else + dir = SDW_DATA_DIR_TX; + + intel_pdi_shim_configure(sdw, sdw->pdi); + intel_pdi_alh_configure(sdw, sdw->pdi); + sdw_cdns_config_stream(cdns, ch, dir, sdw->pdi); + + /* Inform DSP about PDI stream number */ + ret = intel_params_stream(sdw, substream, dai, sdw->hw_params, + sdw->instance, + sdw->pdi->intel_alh_id); + if (ret) + goto err; + + ret = sdw_prepare_stream(dma->stream); + +err: + return ret; }

static int intel_trigger(struct snd_pcm_substream *substream, int cmd, @@ -936,6 +972,8 @@ intel_hw_free(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) return ret; }

+ sdw->hw_params = NULL; + sdw->pdi = NULL; sdw_release_stream(dma->stream);

return 0;