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Commit 9fe67711 authored by Tingwei Zhang's avatar Tingwei Zhang Committed by Gerrit - the friendly Code Review server
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coresight: Add support to disable link in later phase 



Some coresight source keeps trace events in buffer after source
is disabled. These trace events need to be flushed out when sink
is disabled otherwise they will be flushed out in next trace
session. In order to flush the data out, all links need to be
kept enabled until sink is disabled. Put the disablement of
link after sink is disabled.

Change-Id: Ie19d5acf622e9ce256f121c05a0d70a8d303d76a
Signed-off-by: default avatarTingwei Zhang <tingwei@codeaurora.org>
parent b53cdddc

drivers/hwtracing/coresight/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -212,4 +212,13 @@ config CORESIGHT_TGU 
	  used to monitor a data stream to detect protocol violations and to

	  provide a trigger point for centering data around a specific event

	  within the trace data buffer.



config CORESIGHT_LINK_LATE_DISABLE

	bool "Disable CoreSight link after sink is disabled"

	depends on CORESIGHT_LINKS_AND_SINKS

	help

	  CoreSight link won't be disabled until the sink of trace path is

	  disabled. Otherwise, link is disabled when it's not active. Enable

	  this when some CoreSight source holds trace data after disabled.

	  This data will be flushed out when CoreSight sink is disabled.

endif

drivers/hwtracing/coresight/coresight.c

+65 −1
Original line number Diff line number Diff line
@@ -47,6 +47,19 @@ struct coresight_path { 
	struct list_head link;

};



struct coresight_link {

	struct coresight_device *csdev;

	int inport;

	int outport;

};



struct coresight_link_node {

	struct coresight_link *cs_link;

	struct list_head link;

};



static LIST_HEAD(cs_disabled_link);



static LIST_HEAD(cs_active_paths);



/*
@@ -202,6 +215,53 @@ static int coresight_find_link_outport(struct coresight_device *csdev, 
	return -ENODEV;

}



static void coresight_disable_links(void)

{

	struct coresight_link_node *node;

	struct coresight_link_node *node_next;

	struct device *dev;

	struct coresight_device *csdev;



	list_for_each_entry_safe(node, node_next, &cs_disabled_link, link) {

		csdev = node->cs_link->csdev;

		if (link_ops(csdev)->disable) {

			link_ops(csdev)->disable(csdev, node->cs_link->inport,

					node->cs_link->outport);

			coresight_disable_reg_clk(csdev);

		}

		dev = &node->cs_link->csdev->dev;

		devm_kfree(dev, node->cs_link);

		node->cs_link = NULL;

		list_del(&node->link);

		devm_kfree(dev, node);

	}

}



static void coresight_add_disabled_link(struct coresight_device *csdev,

					int inport, int outport)

{

	struct coresight_link_node *node;

	struct coresight_link *cs_link;



	if (csdev) {

		cs_link = devm_kzalloc(&csdev->dev,

				sizeof(struct coresight_link), GFP_KERNEL);

		if (!cs_link)

			return;

		node = devm_kzalloc(&csdev->dev,

				sizeof(struct coresight_link_node), GFP_KERNEL);

		if (!node) {

			devm_kfree(&csdev->dev, cs_link);

			return;

		}

		cs_link->csdev = csdev;

		cs_link->inport = inport;

		cs_link->outport = outport;

		node->cs_link = cs_link;

		list_add(&node->link, &cs_disabled_link);

	}

}



static int coresight_enable_sink(struct coresight_device *csdev, u32 mode)

{

	int ret;
@@ -229,6 +289,8 @@ static void coresight_disable_sink(struct coresight_device *csdev) 
		if (sink_ops(csdev)->disable) {

			sink_ops(csdev)->disable(csdev);

			coresight_disable_reg_clk(csdev);

			if (coresight_link_late_disable())

				coresight_disable_links();

			csdev->enable = false;

			csdev->activated = false;

		}
@@ -306,7 +368,9 @@ static void coresight_disable_link(struct coresight_device *csdev, 
	}



	if (atomic_dec_return(&csdev->refcnt[refport]) == 0) {

		if (link_ops(csdev)->disable) {

		if (coresight_link_late_disable()) {

			coresight_add_disabled_link(csdev, inport, outport);

		} else if (link_ops(csdev)->disable) {

			link_ops(csdev)->disable(csdev, inport, outport);

			coresight_disable_reg_clk(csdev);

		}

include/linux/coresight.h

+7 −0
Original line number Diff line number Diff line
@@ -299,6 +299,13 @@ extern int coresight_timeout(void __iomem *addr, u32 offset, 
extern void coresight_abort(void);

extern void coresight_disable_reg_clk(struct coresight_device *csdev);

extern int coresight_enable_reg_clk(struct coresight_device *csdev);

static inline bool coresight_link_late_disable(void)

{

	if (IS_ENABLED(CONFIG_CORESIGHT_LINK_LATE_DISABLE))

		return true;

	else

		return false;

}

#else

static inline struct coresight_device *

coresight_register(struct coresight_desc *desc) { return NULL; }