5 files changed, 58 insertions, 4 deletions
diff --git a/drivers/net/wireless/mediatek/mt76/Makefile b/drivers/net/wireless/mediatek/mt76/Makefile
index 4d03596e891f..d7a1ddc9e407 100644
--- a/drivers/net/wireless/mediatek/mt76/Makefile
+++ b/drivers/net/wireless/mediatek/mt76/Makefile
@@ -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)
diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index c747eb24581c..8f69d00bd940 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -53,8 +53,10 @@ mt76_dma_add_buf(struct mt76_dev *dev, struct mt76_queue *q,
 	u32 ctrl;
 	int i, idx = -1;
 
-	if (txwi)
+	if (txwi) {
 		q->entry[q->head].txwi = DMA_DUMMY_DATA;
+		q->entry[q->head].skip_buf0 = true;
+	}
 
 	for (i = 0; i < nbufs; i += 2, buf += 2) {
 		u32 buf0 = buf[0].addr, buf1 = 0;
@@ -97,7 +99,7 @@ mt76_dma_tx_cleanup_idx(struct mt76_dev *dev, struct mt76_queue *q, int idx,
 	__le32 __ctrl = READ_ONCE(q->desc[idx].ctrl);
 	u32 ctrl = le32_to_cpu(__ctrl);
 
-	if (!e->txwi || !e->skb) {
+	if (!e->skip_buf0) {
 		__le32 addr = READ_ONCE(q->desc[idx].buf0);
 		u32 len = FIELD_GET(MT_DMA_CTL_SD_LEN0, ctrl);
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 570c159515a0..8aec7ccf2d79 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -93,8 +93,9 @@ struct mt76_queue_entry {
 		struct urb *urb;
 	};
 	enum mt76_txq_id qid;
-	bool schedule;
-	bool done;
+	bool skip_buf0:1;
+	bool schedule:1;
+	bool done:1;
 };
 
 struct mt76_queue_regs {
@@ -578,6 +579,7 @@ 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)
 {
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c b/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
index 73c3104f8858..cf611d1b817c 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
@@ -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:
diff --git a/drivers/net/wireless/mediatek/mt76/pci.c b/drivers/net/wireless/mediatek/mt76/pci.c
new file mode 100644
index 000000000000..04c5a692bc85
--- /dev/null
+++ b/drivers/net/wireless/mediatek/mt76/pci.c
@@ -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);