[PATCH v2 07/13] mt76: Remove unreliable pci_disable_link_state() workaround

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

pci_disable_link_state() was made reliable regardless of ASPM CONFIG
and OS being disallowed to change ASPM states to allow drivers to rely
on pci_disable_link_state() working.

Remove driver working around unreliable pci_disable_link_state() from
mt76 driver and just call pci_disable_link_state() directly.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---

It's a bit unclear which of these devices really need ASPM disabled.
Probably all 76xx given the commit messages that added their disabling
but 79xx seems a lot more uncertain and handwavy.

mt7915 was done without observing any issue in commit 03b3dedc5de1
("mt76: mt7915: disable ASPM").

mt7921 re-enabled aspm in bf3747ae2e25 ("mt76: mt7921: enable aspm by
default").

mt7996 was added with aspm disabled.

I didn't convert these to quirk due to how unclear the situation
currently is (but for 76xx quirk would seem justified as there is
actually some evidence to back aspm being harmful).
---
 drivers/net/wireless/mediatek/mt76/Makefile   |  1 -
 drivers/net/wireless/mediatek/mt76/mt76.h     |  1 -
 .../net/wireless/mediatek/mt76/mt7615/pci.c   |  2 +-
 .../net/wireless/mediatek/mt76/mt76x0/pci.c   |  2 +-
 .../net/wireless/mediatek/mt76/mt76x2/pci.c   |  2 +-
 .../net/wireless/mediatek/mt76/mt7915/pci.c   |  2 +-
 .../net/wireless/mediatek/mt76/mt7921/pci.c   |  2 +-
 .../net/wireless/mediatek/mt76/mt7996/pci.c   |  2 +-
 drivers/net/wireless/mediatek/mt76/pci.c      | 47 -------------------
 9 files changed, 6 insertions(+), 55 deletions(-)
 delete mode 100644 drivers/net/wireless/mediatek/mt76/pci.c

diff --git a/drivers/net/wireless/mediatek/mt76/Makefile b/drivers/net/wireless/mediatek/mt76/Makefile
index 85c4799be954..cb28cef780a5 100644
--- a/drivers/net/wireless/mediatek/mt76/Makefile
+++ b/drivers/net/wireless/mediatek/mt76/Makefile
@@ -12,7 +12,6 @@ mt76-y := \
 	mmio.o util.o trace.o dma.o mac80211.o debugfs.o eeprom.o \
 	tx.o agg-rx.o mcu.o
 
-mt76-$(CONFIG_PCI) += pci.o
 mt76-$(CONFIG_NL80211_TESTMODE) += testmode.o
 
 mt76-usb-y := usb.o usb_trace.o
diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index e8757865a3d0..0869fe03e3d2 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -1038,7 +1038,6 @@ bool ____mt76_poll_msec(struct mt76_dev *dev, u32 offset, u32 mask, u32 val,
 #define mt76_poll_msec_tick(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/mt7615/pci.c b/drivers/net/wireless/mediatek/mt76/mt7615/pci.c
index 9f43e673518b..d43efe4bf9e3 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/pci.c
@@ -43,7 +43,7 @@ static int mt7615_pci_probe(struct pci_dev *pdev,
 	if (ret)
 		goto error;
 
-	mt76_pci_disable_aspm(pdev);
+	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1);
 
 	map = id->device == 0x7663 ? mt7663e_reg_map : mt7615e_reg_map;
 	ret = mt7615_mmio_probe(&pdev->dev, pcim_iomap_table(pdev)[0],
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c b/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c
index 9277ff38b7a2..49c7a63cb1f6 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c
@@ -181,7 +181,7 @@ mt76x0e_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (ret)
 		return ret;
 
-	mt76_pci_disable_aspm(pdev);
+	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1);
 
 	mdev = mt76_alloc_device(&pdev->dev, sizeof(*dev), &mt76x0e_ops,
 				 &drv_ops);
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c b/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
index df85ebc6e1df..de6eb593ab59 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2/pci.c
@@ -85,7 +85,7 @@ mt76x2e_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);
+	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1);
 
 	return 0;
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/pci.c b/drivers/net/wireless/mediatek/mt76/mt7915/pci.c
index 39132894e8ea..8cf9a1a6d851 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/pci.c
@@ -122,7 +122,7 @@ static int mt7915_pci_probe(struct pci_dev *pdev,
 	if (ret)
 		return ret;
 
-	mt76_pci_disable_aspm(pdev);
+	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1);
 
 	if (id->device == 0x7916 || id->device == 0x790a)
 		return mt7915_pci_hif2_probe(pdev);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
index 3dda84a93717..45a861122926 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
@@ -294,7 +294,7 @@ static int mt7921_pci_probe(struct pci_dev *pdev,
 		goto err_free_pci_vec;
 
 	if (mt7921_disable_aspm)
-		mt76_pci_disable_aspm(pdev);
+		pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1);
 
 	ops = mt792x_get_mac80211_ops(&pdev->dev, &mt7921_ops,
 				      (void *)id->driver_data, &features);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/pci.c b/drivers/net/wireless/mediatek/mt76/mt7996/pci.c
index c5301050ff8b..1e84c1f37c37 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/pci.c
@@ -111,7 +111,7 @@ static int mt7996_pci_probe(struct pci_dev *pdev,
 	if (ret)
 		return ret;
 
-	mt76_pci_disable_aspm(pdev);
+	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1);
 
 	if (id->device == 0x7991)
 		return mt7996_pci_hif2_probe(pdev);
diff --git a/drivers/net/wireless/mediatek/mt76/pci.c b/drivers/net/wireless/mediatek/mt76/pci.c
deleted file mode 100644
index 4c1c159fbb62..000000000000
--- a/drivers/net/wireless/mediatek/mt76/pci.c
+++ /dev/null
@@ -1,47 +0,0 @@
-// SPDX-License-Identifier: ISC
-/*
- * Copyright (C) 2019 Lorenzo Bianconi <lorenzo@kernel.org>
- */
-
-#include "mt76.h"
-#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);
-- 
2.30.2