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Revision a7d8d1c7a7f73e780aa9ae74926ae5985b2f895f authored by Andrew Lunn on 14 June 2021, 15:55:23 UTC, committed by Greg Kroah-Hartman on 17 June 2021, 13:34:21 UTC 
usb: core: hub: Disable autosuspend for Cypress CY7C65632
 
The Cypress CY7C65632 appears to have an issue with auto suspend and
detecting devices, not too dissimilar to the SMSC 5534B hub. It is
easiest to reproduce by connecting multiple mass storage devices to
the hub at the same time. On a Lenovo Yoga, around 1 in 3 attempts
result in the devices not being detected. It is however possible to
make them appear using lsusb -v.

Disabling autosuspend for this hub resolves the issue.

Fixes: 1208f9e1d758 ("USB: hub: Fix the broken detection of USB3 device in SMSC hub")
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20210614155524.2228800-1-andrew@lunn.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 parent 60ed39d
Raw File
backtracetest.c 
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Simple stack backtrace regression test module
 *
 * (C) Copyright 2008 Intel Corporation
 * Author: Arjan van de Ven <arjan@linux.intel.com>
 */

#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>

static void backtrace_test_normal(void)
{
	pr_info("Testing a backtrace from process context.\n");
	pr_info("The following trace is a kernel self test and not a bug!\n");

	dump_stack();
}

static DECLARE_COMPLETION(backtrace_work);

static void backtrace_test_irq_callback(unsigned long data)
{
	dump_stack();
	complete(&backtrace_work);
}

static DECLARE_TASKLET_OLD(backtrace_tasklet, &backtrace_test_irq_callback);

static void backtrace_test_irq(void)
{
	pr_info("Testing a backtrace from irq context.\n");
	pr_info("The following trace is a kernel self test and not a bug!\n");

	init_completion(&backtrace_work);
	tasklet_schedule(&backtrace_tasklet);
	wait_for_completion(&backtrace_work);
}

#ifdef CONFIG_STACKTRACE
static void backtrace_test_saved(void)
{
	unsigned long entries[8];
	unsigned int nr_entries;

	pr_info("Testing a saved backtrace.\n");
	pr_info("The following trace is a kernel self test and not a bug!\n");

	nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
	stack_trace_print(entries, nr_entries, 0);
}
#else
static void backtrace_test_saved(void)
{
	pr_info("Saved backtrace test skipped.\n");
}
#endif

static int backtrace_regression_test(void)
{
	pr_info("====[ backtrace testing ]===========\n");

	backtrace_test_normal();
	backtrace_test_irq();
	backtrace_test_saved();

	pr_info("====[ end of backtrace testing ]====\n");
	return 0;
}

static void exitf(void)
{
}

module_init(backtrace_regression_test);
module_exit(exitf);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
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