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mt76: mt76x2e: disable pcie_aspm by default

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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: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
This commit is contained in:
Lorenzo Bianconi 2019-10-27 20:53:08 +01:00 committed by Kalle Valo
parent b43f4a169f
commit f37f055035
4 changed files with 51 additions and 0 deletions
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2
drivers/net/wireless/mediatek/mt76/Makefile
View File

@ -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)

1
drivers/net/wireless/mediatek/mt76/mt76.h
View File

@ -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)
{

2
drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
View File

@ -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:

46
drivers/net/wireless/mediatek/mt76/pci.c Normal file
View File

@ -0,0 +1,46 @@
// 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);