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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
ad525x_dpot-i2c.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Driver for the Analog Devices digital potentiometers (I2C bus)
 *
 * Copyright (C) 2010-2011 Michael Hennerich, Analog Devices Inc.
 */

#include <linux/i2c.h>
#include <linux/module.h>

#include "ad525x_dpot.h"

/* I2C bus functions */
static int write_d8(void *client, u8 val)
{
	return i2c_smbus_write_byte(client, val);
}

static int write_r8d8(void *client, u8 reg, u8 val)
{
	return i2c_smbus_write_byte_data(client, reg, val);
}

static int write_r8d16(void *client, u8 reg, u16 val)
{
	return i2c_smbus_write_word_data(client, reg, val);
}

static int read_d8(void *client)
{
	return i2c_smbus_read_byte(client);
}

static int read_r8d8(void *client, u8 reg)
{
	return i2c_smbus_read_byte_data(client, reg);
}

static int read_r8d16(void *client, u8 reg)
{
	return i2c_smbus_read_word_data(client, reg);
}

static const struct ad_dpot_bus_ops bops = {
	.read_d8	= read_d8,
	.read_r8d8	= read_r8d8,
	.read_r8d16	= read_r8d16,
	.write_d8	= write_d8,
	.write_r8d8	= write_r8d8,
	.write_r8d16	= write_r8d16,
};

static int ad_dpot_i2c_probe(struct i2c_client *client,
				      const struct i2c_device_id *id)
{
	struct ad_dpot_bus_data bdata = {
		.client = client,
		.bops = &bops,
	};

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_WORD_DATA)) {
		dev_err(&client->dev, "SMBUS Word Data not Supported\n");
		return -EIO;
	}

	return ad_dpot_probe(&client->dev, &bdata, id->driver_data, id->name);
}

static int ad_dpot_i2c_remove(struct i2c_client *client)
{
	return ad_dpot_remove(&client->dev);
}

static const struct i2c_device_id ad_dpot_id[] = {
	{"ad5258", AD5258_ID},
	{"ad5259", AD5259_ID},
	{"ad5251", AD5251_ID},
	{"ad5252", AD5252_ID},
	{"ad5253", AD5253_ID},
	{"ad5254", AD5254_ID},
	{"ad5255", AD5255_ID},
	{"ad5241", AD5241_ID},
	{"ad5242", AD5242_ID},
	{"ad5243", AD5243_ID},
	{"ad5245", AD5245_ID},
	{"ad5246", AD5246_ID},
	{"ad5247", AD5247_ID},
	{"ad5248", AD5248_ID},
	{"ad5280", AD5280_ID},
	{"ad5282", AD5282_ID},
	{"adn2860", ADN2860_ID},
	{"ad5273", AD5273_ID},
	{"ad5161", AD5161_ID},
	{"ad5171", AD5171_ID},
	{"ad5170", AD5170_ID},
	{"ad5172", AD5172_ID},
	{"ad5173", AD5173_ID},
	{"ad5272", AD5272_ID},
	{"ad5274", AD5274_ID},
	{}
};
MODULE_DEVICE_TABLE(i2c, ad_dpot_id);

static struct i2c_driver ad_dpot_i2c_driver = {
	.driver = {
		.name	= "ad_dpot",
	},
	.probe		= ad_dpot_i2c_probe,
	.remove		= ad_dpot_i2c_remove,
	.id_table	= ad_dpot_id,
};

module_i2c_driver(ad_dpot_i2c_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("digital potentiometer I2C bus driver");
MODULE_LICENSE("GPL");
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