Skip to main content

Browse the archive

https://github.com/torvalds/linux
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
gpio-tps65912.c 
// SPDX-License-Identifier: GPL-2.0
/*
 * GPIO driver for TI TPS65912x PMICs
 *
 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
 *	Andrew F. Davis <afd@ti.com>
 *
 * Based on the Arizona GPIO driver and the previous TPS65912 driver by
 * Margarita Olaya Cabrera <magi@slimlogic.co.uk>
 */

#include <linux/gpio/driver.h>
#include <linux/module.h>
#include <linux/platform_device.h>

#include <linux/mfd/tps65912.h>

struct tps65912_gpio {
	struct gpio_chip gpio_chip;
	struct tps65912 *tps;
};

static int tps65912_gpio_get_direction(struct gpio_chip *gc,
				       unsigned offset)
{
	struct tps65912_gpio *gpio = gpiochip_get_data(gc);

	int ret, val;

	ret = regmap_read(gpio->tps->regmap, TPS65912_GPIO1 + offset, &val);
	if (ret)
		return ret;

	if (val & GPIO_CFG_MASK)
		return GPIO_LINE_DIRECTION_OUT;
	else
		return GPIO_LINE_DIRECTION_IN;
}

static int tps65912_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
{
	struct tps65912_gpio *gpio = gpiochip_get_data(gc);

	return regmap_update_bits(gpio->tps->regmap, TPS65912_GPIO1 + offset,
				  GPIO_CFG_MASK, 0);
}

static int tps65912_gpio_direction_output(struct gpio_chip *gc,
					  unsigned offset, int value)
{
	struct tps65912_gpio *gpio = gpiochip_get_data(gc);

	/* Set the initial value */
	regmap_update_bits(gpio->tps->regmap, TPS65912_GPIO1 + offset,
			   GPIO_SET_MASK, value ? GPIO_SET_MASK : 0);

	return regmap_update_bits(gpio->tps->regmap, TPS65912_GPIO1 + offset,
				  GPIO_CFG_MASK, GPIO_CFG_MASK);
}

static int tps65912_gpio_get(struct gpio_chip *gc, unsigned offset)
{
	struct tps65912_gpio *gpio = gpiochip_get_data(gc);
	int ret, val;

	ret = regmap_read(gpio->tps->regmap, TPS65912_GPIO1 + offset, &val);
	if (ret)
		return ret;

	if (val & GPIO_STS_MASK)
		return 1;

	return 0;
}

static void tps65912_gpio_set(struct gpio_chip *gc, unsigned offset,
			      int value)
{
	struct tps65912_gpio *gpio = gpiochip_get_data(gc);

	regmap_update_bits(gpio->tps->regmap, TPS65912_GPIO1 + offset,
			   GPIO_SET_MASK, value ? GPIO_SET_MASK : 0);
}

static const struct gpio_chip template_chip = {
	.label			= "tps65912-gpio",
	.owner			= THIS_MODULE,
	.get_direction		= tps65912_gpio_get_direction,
	.direction_input	= tps65912_gpio_direction_input,
	.direction_output	= tps65912_gpio_direction_output,
	.get			= tps65912_gpio_get,
	.set			= tps65912_gpio_set,
	.base			= -1,
	.ngpio			= 5,
	.can_sleep		= true,
};

static int tps65912_gpio_probe(struct platform_device *pdev)
{
	struct tps65912 *tps = dev_get_drvdata(pdev->dev.parent);
	struct tps65912_gpio *gpio;
	int ret;

	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
	if (!gpio)
		return -ENOMEM;

	gpio->tps = dev_get_drvdata(pdev->dev.parent);
	gpio->gpio_chip = template_chip;
	gpio->gpio_chip.parent = tps->dev;

	ret = devm_gpiochip_add_data(&pdev->dev, &gpio->gpio_chip,
				     gpio);
	if (ret < 0) {
		dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
		return ret;
	}

	platform_set_drvdata(pdev, gpio);

	return 0;
}

static const struct platform_device_id tps65912_gpio_id_table[] = {
	{ "tps65912-gpio", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, tps65912_gpio_id_table);

static struct platform_driver tps65912_gpio_driver = {
	.driver = {
		.name = "tps65912-gpio",
	},
	.probe = tps65912_gpio_probe,
	.id_table = tps65912_gpio_id_table,
};
module_platform_driver(tps65912_gpio_driver);

MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_DESCRIPTION("TPS65912 GPIO driver");
MODULE_LICENSE("GPL v2");
back to top