From 5f61975f7efca24d17a4381112433a9c6e083658 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Mon, 21 Jun 2021 18:12:46 +0300 Subject: [PATCH] intel_th: Wait until port is in reset before programming it [ Upstream commit ab1afed701d2db7eb35c1a2526a29067a38e93d1 ] Some devices don't drain their pipelines if we don't make sure that the corresponding output port is in reset before programming it for a new trace capture, resulting in bits of old trace appearing in the new trace capture. Fix that by explicitly making sure the reset is asserted before programming new trace capture. Reviewed-by: Andy Shevchenko Signed-off-by: Alexander Shishkin Link: https://lore.kernel.org/r/20210621151246.31891-5-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/hwtracing/intel_th/core.c | 17 +++++++++++++++++ drivers/hwtracing/intel_th/gth.c | 16 ++++++++++++++++ drivers/hwtracing/intel_th/intel_th.h | 3 +++ 3 files changed, 36 insertions(+) diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c index c9ac3dc651135..9cb8c7d13d46b 100644 --- a/drivers/hwtracing/intel_th/core.c +++ b/drivers/hwtracing/intel_th/core.c @@ -215,6 +215,22 @@ static ssize_t port_show(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RO(port); +static void intel_th_trace_prepare(struct intel_th_device *thdev) +{ + struct intel_th_device *hub = to_intel_th_hub(thdev); + struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver); + + if (hub->type != INTEL_TH_SWITCH) + return; + + if (thdev->type != INTEL_TH_OUTPUT) + return; + + pm_runtime_get_sync(&thdev->dev); + hubdrv->prepare(hub, &thdev->output); + pm_runtime_put(&thdev->dev); +} + static int intel_th_output_activate(struct intel_th_device *thdev) { struct intel_th_driver *thdrv = @@ -235,6 +251,7 @@ static int intel_th_output_activate(struct intel_th_device *thdev) if (ret) goto fail_put; + intel_th_trace_prepare(thdev); if (thdrv->activate) ret = thdrv->activate(thdev); else diff --git a/drivers/hwtracing/intel_th/gth.c b/drivers/hwtracing/intel_th/gth.c index 28509b02a0b56..b3308934a687d 100644 --- a/drivers/hwtracing/intel_th/gth.c +++ b/drivers/hwtracing/intel_th/gth.c @@ -564,6 +564,21 @@ static void gth_tscu_resync(struct gth_device *gth) iowrite32(reg, gth->base + REG_TSCU_TSUCTRL); } +static void intel_th_gth_prepare(struct intel_th_device *thdev, + struct intel_th_output *output) +{ + struct gth_device *gth = dev_get_drvdata(&thdev->dev); + int count; + + /* + * Wait until the output port is in reset before we start + * programming it. + */ + for (count = GTH_PLE_WAITLOOP_DEPTH; + count && !(gth_output_get(gth, output->port) & BIT(5)); count--) + cpu_relax(); +} + /** * intel_th_gth_enable() - enable tracing to an output device * @thdev: GTH device @@ -815,6 +830,7 @@ static struct intel_th_driver intel_th_gth_driver = { .assign = intel_th_gth_assign, .unassign = intel_th_gth_unassign, .set_output = intel_th_gth_set_output, + .prepare = intel_th_gth_prepare, .enable = intel_th_gth_enable, .trig_switch = intel_th_gth_switch, .disable = intel_th_gth_disable, diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h index 5fe694708b7a3..595615b791086 100644 --- a/drivers/hwtracing/intel_th/intel_th.h +++ b/drivers/hwtracing/intel_th/intel_th.h @@ -143,6 +143,7 @@ intel_th_output_assigned(struct intel_th_device *thdev) * @remove: remove method * @assign: match a given output type device against available outputs * @unassign: deassociate an output type device from an output port + * @prepare: prepare output port for tracing * @enable: enable tracing for a given output device * @disable: disable tracing for a given output device * @irq: interrupt callback @@ -164,6 +165,8 @@ struct intel_th_driver { struct intel_th_device *othdev); void (*unassign)(struct intel_th_device *thdev, struct intel_th_device *othdev); + void (*prepare)(struct intel_th_device *thdev, + struct intel_th_output *output); void (*enable)(struct intel_th_device *thdev, struct intel_th_output *output); void (*trig_switch)(struct intel_th_device *thdev, -- 2.47.2