Re: [PATCH 1/2] PCI/AER: Disable AER interrupt during suspend
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2021-01-27 20:51:57
Also in:
linux-pci, lkml
On Thu, Jan 28, 2021 at 01:31:00AM +0800, Kai-Heng Feng wrote:
Commit 50310600ebda ("iommu/vt-d: Enable PCI ACS for platform opt in
hint") enables ACS, and some platforms lose its NVMe after resume from
firmware:
[ 50.947816] pcieport 0000:00:1b.0: DPC: containment event, status:0x1f01 source:0x0000
[ 50.947817] pcieport 0000:00:1b.0: DPC: unmasked uncorrectable error detected
[ 50.947829] pcieport 0000:00:1b.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), type=Transaction Layer, (Receiver ID)
[ 50.947830] pcieport 0000:00:1b.0: device [8086:06ac] error status/mask=00200000/00010000
[ 50.947831] pcieport 0000:00:1b.0: [21] ACSViol (First)
[ 50.947841] pcieport 0000:00:1b.0: AER: broadcast error_detected message
[ 50.947843] nvme nvme0: frozen state error detected, reset controller
It happens right after ACS gets enabled during resume.
To prevent that from happening, disable AER interrupt and enable it on
system suspend and resume, respectively.Lots of questions here. Maybe this is what we'll end up doing, but I am curious about why the error is reported in the first place. Is this a consequence of the link going down and back up? Is it consequence of the device doing a DMA when it shouldn't? Are we doing something in the wrong order during suspend? Or maybe resume, since I assume the error is reported during resume? If we *do* take the error, why doesn't DPC recovery work?
quoted hunk ↗ jump to hunk
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=209149 Fixes: 50310600ebda ("iommu/vt-d: Enable PCI ACS for platform opt in hint") Signed-off-by: Kai-Heng Feng <redacted> --- drivers/pci/pcie/aer.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c index 77b0f2c45bc0..0e9a85530ae6 100644 --- a/drivers/pci/pcie/aer.c +++ b/drivers/pci/pcie/aer.c@@ -1365,6 +1365,22 @@ static int aer_probe(struct pcie_device *dev) return 0; } +static int aer_suspend(struct pcie_device *dev) +{ + struct aer_rpc *rpc = get_service_data(dev); + + aer_disable_rootport(rpc); + return 0; +} + +static int aer_resume(struct pcie_device *dev) +{ + struct aer_rpc *rpc = get_service_data(dev); + + aer_enable_rootport(rpc); + return 0; +} + /** * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP * @dev: pointer to Root Port, RCEC, or RCiEP@@ -1437,6 +1453,8 @@ static struct pcie_port_service_driver aerdriver = { .service = PCIE_PORT_SERVICE_AER, .probe = aer_probe, + .suspend = aer_suspend, + .resume = aer_resume, .remove = aer_remove, };-- 2.29.2