USB: Debug: Add centralized debug buffer for USB drivers (0505f577) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/usb/gadget/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@ obj-$(CONFIG_USB_LIBCOMPOSITE) += libcomposite.o
		libcomposite-y := usbstring.o config.o epautoconf.o
		libcomposite-y += composite.o functions.o configfs.o u_f.o

		obj-y += debug.o
		g_android-y := android.o

		obj-$(CONFIG_USB_GADGET) += udc/ function/ legacy/

drivers/usb/gadget/android.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -67,6 +67,7 @@
		#include "f_mass_storage.h"

		USB_ETHERNET_MODULE_PARAMETERS();
		#include "debug.h"

		MODULE_AUTHOR("Mike Lockwood");
		MODULE_DESCRIPTION("Android Composite USB Driver");
		@@ -3822,6 +3823,8 @@ static int android_probe(struct platform_device *pdev)
		list_add_tail(&android_dev->list_item, &android_dev_list);
		android_dev_count++;

		debug_debugfs_init();

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		if (res) {
		diag_dload = devm_ioremap(&pdev->dev, res->start,
		@@ -3883,6 +3886,7 @@ err_alloc:
		class_destroy(android_class);
		android_class = NULL;
		}
		debug_debugfs_exit();
		return ret;
		}

		@@ -3903,6 +3907,8 @@ static int android_remove(struct platform_device *pdev)
		break;
		}

		debug_debugfs_exit();

		if (dev) {
		android_destroy_device(dev);
		if (pdata && pdata->pm_qos_latency[0])

drivers/usb/gadget/debug.c

0 → 100644

+133 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2015, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		* only version 2 as published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		*/

		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/sched.h>
		#include <linux/rwlock.h>
		#include <linux/debugfs.h>

		#include "debug.h"

		#define dbg_inc(i) ((i+1) % DBG_MAX_MSG)

		#define ENABLE_EVENT_LOG 1
		unsigned int enable_event_log = ENABLE_EVENT_LOG;
		module_param(enable_event_log, uint, S_IRUGO \| S_IWUSR);
		MODULE_PARM_DESC(enable_event_log, "enable event logging in debug buffer");

		static struct {
		char buf[DBG_MAX_MSG][DBG_MSG_LEN]; /* buffer */
		unsigned idx; /* index */
		rwlock_t lck; /* lock */
		struct dentry *root;
		} __maybe_unused dbg_buffer = {
		.idx = 0,
		.lck = __RW_LOCK_UNLOCKED(lck),
		.root = NULL
		};

		void __maybe_unused put_timestamp(char *tbuf)
		{
		unsigned long long t;
		unsigned long nanosec_rem;
		unsigned long flags;

		write_lock_irqsave(&dbg_buffer.lck, flags);
		t = cpu_clock(smp_processor_id());
		write_unlock_irqrestore(&dbg_buffer.lck, flags);
		nanosec_rem = do_div(t, 1000000000)/1000;
		snprintf(tbuf, TIME_BUF_LEN, "[%5lu.%06lu]: ", (unsigned long)t,
		nanosec_rem);
		}

		void __maybe_unused add_event_to_buf(char *tbuf)
		{
		unsigned long flags;
		char *buf;
		write_lock_irqsave(&dbg_buffer.lck, flags);
		buf = dbg_buffer.buf[dbg_buffer.idx];
		memcpy(buf, tbuf, DBG_MSG_LEN);
		dbg_buffer.idx = (dbg_buffer.idx + 1) % DBG_MAX_MSG;
		write_unlock_irqrestore(&dbg_buffer.lck, flags);
		}

		static int dbg_read_buf_show(struct seq_file s, void unused)
		{
		unsigned long flags;
		unsigned i;

		read_lock_irqsave(&dbg_buffer.lck, flags);

		i = dbg_buffer.idx;
		if (strnlen(dbg_buffer.buf[i], DBG_MSG_LEN))
		seq_printf(s, "%s\n", dbg_buffer.buf[i]);
		for (i = dbg_inc(i); i != dbg_buffer.idx; i = dbg_inc(i)) {
		if (!strnlen(dbg_buffer.buf[i], DBG_MSG_LEN))
		continue;
		seq_printf(s, "%s\n", dbg_buffer.buf[i]);
		}

		read_unlock_irqrestore(&dbg_buffer.lck, flags);

		return 0;
		}

		static int dbg_read_buf_open(struct inode inode, struct file file)
		{
		return single_open(file, dbg_read_buf_show, inode->i_private);
		}

		const struct file_operations dbg_read_buf_fops = {
		.open = dbg_read_buf_open,
		.read = seq_read,
		.llseek = seq_lseek,
		.release = single_release,
		};

		int debug_debugfs_init(void)
		{
		struct dentry *root;
		struct dentry *file;
		int ret;

		root = debugfs_create_dir("debug", NULL);
		if (!root) {
		ret = -ENOMEM;
		goto err0;
		}

		dbg_buffer.root = root;

		file = debugfs_create_file("read_buf", S_IRUGO, root,
		NULL, &dbg_read_buf_fops);
		if (!file) {
		ret = -ENOMEM;
		goto err1;
		}

		return 0;

		err1:
		debugfs_remove_recursive(root);

		err0:
		return ret;
		}

		void debug_debugfs_exit(void)
		{
		debugfs_remove_recursive(dbg_buffer.root);
		dbg_buffer.root = NULL;
		}

drivers/usb/gadget/debug.h

0 → 100644

+41 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2015, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		* only version 2 as published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		*/

		#ifndef __DEBUG_H_
		#define __DEBUG_H_

		#define DBG_MAX_MSG 512UL
		#define DBG_MSG_LEN 160UL
		#define TIME_BUF_LEN 17
		#define DBG_EVENT_LEN 143

		extern unsigned int enable_event_log;
		extern void put_timestamp(char *tbuf);
		extern void add_event_to_buf(char *tbuf);
		extern int debug_debugfs_init(void);
		extern void debug_debugfs_exit(void);

		#define log_event(dlog, x...) \
		do { \
		char buf[160]; \
		if (dlog) \
		pr_debug(x); \
		if (enable_event_log) { \
		put_timestamp(buf); \
		snprintf(&buf[TIME_BUF_LEN - 1], DBG_EVENT_LEN, x); \
		add_event_to_buf(buf); \
		} \
		} while (0)

		#endif /* __DEBUG_H_ */