From: Kai-Heng Feng <kai.heng.feng@canonical.com> To: jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com Cc: acelan.kao@canonical.com, Kai-Heng Feng <kai.heng.feng@canonical.com>, "David S. Miller" <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>, intel-wired-lan@lists.osuosl.org (moderated list:INTEL ETHERNET DRIVERS), netdev@vger.kernel.org (open list:NETWORKING DRIVERS), linux-kernel@vger.kernel.org (open list) Subject: [PATCH 3/3] e1000e: Serialize TGP e1000e PM ops Date: Mon, 12 Jul 2021 21:34:59 +0800 [thread overview] Message-ID: <20210712133500.1126371-3-kai.heng.feng@canonical.com> (raw) In-Reply-To: <20210712133500.1126371-1-kai.heng.feng@canonical.com> On TGL systems, PCI_COMMAND may randomly flip to 0 on system resume. This is devastating to drivers that use pci_set_master(), like NVMe and xHCI, to enable DMA in their resume routine, as pci_set_master() can inadvertently disable PCI_COMMAND_IO and PCI_COMMAND_MEMORY, making resources inaccessible. The issue is reproducible on all kernel releases, but the situation is exacerbated by commit 6cecf02e77ab ("Revert "e1000e: disable s0ix entry and exit flows for ME systems""). Seems like ME can do many things to other PCI devices until it's finally out of ULP polling. So ensure e1000e PM ops are serialized by enforcing suspend/resume order to workaround the issue. Of course this will make system suspend and resume a bit slower, but we probably need to settle on this workaround until ME is fully supported. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212039 Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> --- drivers/net/ethernet/intel/e1000e/netdev.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index e63445a8ce12..0244d3dd90a3 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -7319,7 +7319,8 @@ static const struct net_device_ops e1000e_netdev_ops = { static void e1000e_create_device_links(struct pci_dev *pdev) { - struct pci_dev *tgp_mei_me; + struct pci_bus *bus = pdev->bus; + struct pci_dev *tgp_mei_me, *p; /* Find TGP mei_me devices and make e1000e power depend on mei_me */ tgp_mei_me = pci_get_device(PCI_VENDOR_ID_INTEL, 0xa0e0, NULL); @@ -7335,6 +7336,17 @@ static void e1000e_create_device_links(struct pci_dev *pdev) pci_info(pdev, "System and runtime PM depends on %s\n", pci_name(tgp_mei_me)); + /* Find other devices in the SoC and make them depend on e1000e */ + list_for_each_entry(p, &bus->devices, bus_list) { + if (&p->dev == &pdev->dev || &p->dev == &tgp_mei_me->dev) + continue; + + if (device_link_add(&p->dev, &pdev->dev, + DL_FLAG_AUTOREMOVE_SUPPLIER)) + pci_info(p, "System PM depends on %s\n", + pci_name(pdev)); + } + pci_dev_put(tgp_mei_me); } -- 2.31.1
WARNING: multiple messages have this Message-ID (diff)
From: Kai-Heng Feng <kai.heng.feng@canonical.com> To: intel-wired-lan@osuosl.org Subject: [Intel-wired-lan] [PATCH 3/3] e1000e: Serialize TGP e1000e PM ops Date: Mon, 12 Jul 2021 21:34:59 +0800 [thread overview] Message-ID: <20210712133500.1126371-3-kai.heng.feng@canonical.com> (raw) In-Reply-To: <20210712133500.1126371-1-kai.heng.feng@canonical.com> On TGL systems, PCI_COMMAND may randomly flip to 0 on system resume. This is devastating to drivers that use pci_set_master(), like NVMe and xHCI, to enable DMA in their resume routine, as pci_set_master() can inadvertently disable PCI_COMMAND_IO and PCI_COMMAND_MEMORY, making resources inaccessible. The issue is reproducible on all kernel releases, but the situation is exacerbated by commit 6cecf02e77ab ("Revert "e1000e: disable s0ix entry and exit flows for ME systems""). Seems like ME can do many things to other PCI devices until it's finally out of ULP polling. So ensure e1000e PM ops are serialized by enforcing suspend/resume order to workaround the issue. Of course this will make system suspend and resume a bit slower, but we probably need to settle on this workaround until ME is fully supported. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212039 Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> --- drivers/net/ethernet/intel/e1000e/netdev.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index e63445a8ce12..0244d3dd90a3 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -7319,7 +7319,8 @@ static const struct net_device_ops e1000e_netdev_ops = { static void e1000e_create_device_links(struct pci_dev *pdev) { - struct pci_dev *tgp_mei_me; + struct pci_bus *bus = pdev->bus; + struct pci_dev *tgp_mei_me, *p; /* Find TGP mei_me devices and make e1000e power depend on mei_me */ tgp_mei_me = pci_get_device(PCI_VENDOR_ID_INTEL, 0xa0e0, NULL); @@ -7335,6 +7336,17 @@ static void e1000e_create_device_links(struct pci_dev *pdev) pci_info(pdev, "System and runtime PM depends on %s\n", pci_name(tgp_mei_me)); + /* Find other devices in the SoC and make them depend on e1000e */ + list_for_each_entry(p, &bus->devices, bus_list) { + if (&p->dev == &pdev->dev || &p->dev == &tgp_mei_me->dev) + continue; + + if (device_link_add(&p->dev, &pdev->dev, + DL_FLAG_AUTOREMOVE_SUPPLIER)) + pci_info(p, "System PM depends on %s\n", + pci_name(pdev)); + } + pci_dev_put(tgp_mei_me); } -- 2.31.1
next prev parent reply other threads:[~2021-07-12 13:35 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-12 13:34 [PATCH 1/3] e1000e: Separate TGP from SPT Kai-Heng Feng 2021-07-12 13:34 ` [Intel-wired-lan] " Kai-Heng Feng 2021-07-12 13:34 ` [PATCH 2/3] e1000e: Make mei_me active when e1000e is in use Kai-Heng Feng 2021-07-12 13:34 ` [Intel-wired-lan] " Kai-Heng Feng 2021-07-14 5:39 ` Sasha Neftin 2021-07-14 5:39 ` Sasha Neftin 2021-07-14 6:28 ` Kai-Heng Feng 2021-07-14 6:28 ` Kai-Heng Feng 2021-07-14 9:05 ` Ruinskiy, Dima 2021-07-14 9:05 ` Ruinskiy, Dima 2021-07-14 9:52 ` Kai-Heng Feng 2021-07-14 9:52 ` Kai-Heng Feng 2021-07-18 8:37 ` Sasha Neftin 2021-07-18 8:37 ` Sasha Neftin 2021-07-12 13:34 ` Kai-Heng Feng [this message] 2021-07-12 13:34 ` [Intel-wired-lan] [PATCH 3/3] e1000e: Serialize TGP e1000e PM ops Kai-Heng Feng 2021-07-27 6:53 ` Kai-Heng Feng 2021-07-27 6:53 ` [Intel-wired-lan] " Kai-Heng Feng 2021-08-01 4:15 ` Sasha Neftin 2021-08-01 4:15 ` [Intel-wired-lan] " Sasha Neftin 2021-07-13 17:58 ` [Intel-wired-lan] [PATCH 1/3] e1000e: Separate TGP from SPT Sasha Neftin 2021-07-13 17:58 ` Sasha Neftin 2021-07-14 4:19 ` Kai-Heng Feng 2021-07-14 4:19 ` Kai-Heng Feng 2021-07-14 8:43 ` Sasha Neftin 2021-07-14 8:43 ` Sasha Neftin
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