Commit f37f0550 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Kalle Valo
Browse files

mt76: mt76x2e: disable pcie_aspm by default 



On same device (e.g. U7612E-H1) PCIE_ASPM causes continuous mcu hangs and
instability. Since mt76x2 series does not manage PCIE PS states, first we
try to disable ASPM using pci_disable_link_state. If it fails, we will
disable PCIE PS configuring PCI registers.
This patch has been successfully tested on U7612E-H1 mini-pice card

Tested-by: default avatarOleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
parent b43f4a16

drivers/net/wireless/mediatek/mt76/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -8,6 +8,8 @@ mt76-y := \ 
	mmio.o util.o trace.o dma.o mac80211.o debugfs.o eeprom.o \

	tx.o agg-rx.o mcu.o



mt76-$(CONFIG_PCI) += pci.o



mt76-usb-y := usb.o usb_trace.o



CFLAGS_trace.o := -I$(src)

drivers/net/wireless/mediatek/mt76/mt76.h

+1 −0
Original line number Diff line number Diff line
@@ -578,6 +578,7 @@ bool __mt76_poll_msec(struct mt76_dev *dev, u32 offset, u32 mask, u32 val, 
#define mt76_poll_msec(dev, ...) __mt76_poll_msec(&((dev)->mt76), __VA_ARGS__)



void mt76_mmio_init(struct mt76_dev *dev, void __iomem *regs);

void mt76_pci_disable_aspm(struct pci_dev *pdev);



static inline u16 mt76_chip(struct mt76_dev *dev)

{

drivers/net/wireless/mediatek/mt76/mt76x2/pci.c

+2 −0
Original line number Diff line number Diff line
@@ -81,6 +81,8 @@ mt76pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	/* RG_SSUSB_CDR_BR_PE1D = 0x3 */

	mt76_rmw_field(dev, 0x15c58, 0x3 << 6, 0x3);



	mt76_pci_disable_aspm(pdev);



	return 0;



error:

drivers/net/wireless/mediatek/mt76/pci.c

0 → 100644
+46 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: ISC

/*

 * Copyright (C) 2019 Lorenzo Bianconi <lorenzo@kernel.org>

 */



#include <linux/pci.h>



void mt76_pci_disable_aspm(struct pci_dev *pdev)

{

	struct pci_dev *parent = pdev->bus->self;

	u16 aspm_conf, parent_aspm_conf = 0;



	pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &aspm_conf);

	aspm_conf &= PCI_EXP_LNKCTL_ASPMC;

	if (parent) {

		pcie_capability_read_word(parent, PCI_EXP_LNKCTL,

					  &parent_aspm_conf);

		parent_aspm_conf &= PCI_EXP_LNKCTL_ASPMC;

	}



	if (!aspm_conf && (!parent || !parent_aspm_conf)) {

		/* aspm already disabled */

		return;

	}



	dev_info(&pdev->dev, "disabling ASPM %s %s\n",

		 (aspm_conf & PCI_EXP_LNKCTL_ASPM_L0S) ? "L0s" : "",

		 (aspm_conf & PCI_EXP_LNKCTL_ASPM_L1) ? "L1" : "");



	if (IS_ENABLED(CONFIG_PCIEASPM)) {

		int err;



		err = pci_disable_link_state(pdev, aspm_conf);

		if (!err)

			return;

	}



	/* both device and parent should have the same ASPM setting.

	 * disable ASPM in downstream component first and then upstream.

	 */

	pcie_capability_clear_word(pdev, PCI_EXP_LNKCTL, aspm_conf);

	if (parent)

		pcie_capability_clear_word(parent, PCI_EXP_LNKCTL,

					   aspm_conf);

}

EXPORT_SYMBOL_GPL(mt76_pci_disable_aspm);

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