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23 October 2021, 00:29:24 UTC
Revision 275e88b06a277ccf89d9c471a777e9b4f8c552b0 authored by Rob Herring on 18 December 2020, 14:39:05 UTC, committed by Bjorn Helgaas on 26 December 2020, 03:58:36 UTC 
PCI: tegra: Fix host link initialization
 
Commit b9ac0f9dc8ea ("PCI: dwc: Move dw_pcie_setup_rc() to DWC common
code") broke enumeration of downstream devices on Tegra:

In non-working case (next-20201211):

  0001:00:00.0 PCI bridge: NVIDIA Corporation Device 1ad2 (rev a1)
  0001:01:00.0 SATA controller: Marvell Technology Group Ltd. Device 9171 (rev 13)
  0005:00:00.0 PCI bridge: NVIDIA Corporation Device 1ad0 (rev a1)

In working case (v5.10-rc7):

  0001:00:00.0 PCI bridge: Molex Incorporated Device 1ad2 (rev a1)
  0001:01:00.0 SATA controller: Marvell Technology Group Ltd. Device 9171 (rev 13)
  0005:00:00.0 PCI bridge: Molex Incorporated Device 1ad0 (rev a1)
  0005:01:00.0 PCI bridge: PLX Technology, Inc. Device 3380 (rev ab)
  0005:02:02.0 PCI bridge: PLX Technology, Inc. Device 3380 (rev ab)
  0005:03:00.0 USB controller: PLX Technology, Inc. Device 3380 (rev ab)

The problem seems to be dw_pcie_setup_rc() is now called twice before and
after the link up handling. The fix is to move Tegra's link up handling to
.start_link() function like other DWC drivers. Tegra is a bit more
complicated than others as it re-inits the whole DWC controller to retry
the link. With this, the initialization ordering is restored to match the
prior sequence.

Fixes: b9ac0f9dc8ea ("PCI: dwc: Move dw_pcie_setup_rc() to DWC common code")
Link: https://lore.kernel.org/r/20201218143905.1614098-1-robh@kernel.org
Reported-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Vidya Sagar <vidyas@nvidia.com>
1 parent 255b2d5
Raw File
Tip revision: 275e88b06a277ccf89d9c471a777e9b4f8c552b0 authored by Rob Herring on 18 December 2020, 14:39:05 UTC
PCI: tegra: Fix host link initialization
Tip revision: 275e88b
dummy_timer.c 
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/clocksource/dummy_timer.c
 *
 *  Copyright (C) 2013 ARM Ltd.
 *  All Rights Reserved
 */
#include <linux/clockchips.h>
#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/percpu.h>
#include <linux/cpumask.h>

static DEFINE_PER_CPU(struct clock_event_device, dummy_timer_evt);

static int dummy_timer_starting_cpu(unsigned int cpu)
{
	struct clock_event_device *evt = per_cpu_ptr(&dummy_timer_evt, cpu);

	evt->name	= "dummy_timer";
	evt->features	= CLOCK_EVT_FEAT_PERIODIC |
			  CLOCK_EVT_FEAT_ONESHOT |
			  CLOCK_EVT_FEAT_DUMMY;
	evt->rating	= 100;
	evt->cpumask	= cpumask_of(cpu);

	clockevents_register_device(evt);
	return 0;
}

static int __init dummy_timer_register(void)
{
	return cpuhp_setup_state(CPUHP_AP_DUMMY_TIMER_STARTING,
				 "clockevents/dummy_timer:starting",
				 dummy_timer_starting_cpu, NULL);
}
early_initcall(dummy_timer_register);
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