6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Lukas Wunner <lukas@xxxxxxxxx>
commit c9260693aa0c1e029ed23693cfd4d7814eee6624 upstream.
Commit ac91e6980563 ("PCI: Unify delay handling for reset and resume")
shortened an unconditional 1 sec delay after a Secondary Bus Reset to 100
msec for PCIe (per PCIe r6.1 sec 6.6.1). The 1 sec delay is only required
for Conventional PCI.
But it turns out that there are PCIe devices which require a longer delay
than prescribed before first config space access after reset recovery or
resume from D3cold:
Chad reports that a "VideoPropulsion Torrent QN16e" MPEG QAM Modulator
"raises a PCI system error (PERR), as reported by the IPMI event log, and
the hardware itself would suffer a catastrophic event, cycling the server"
unless the longer delay is observed.
The card is specified to conform to PCIe r1.0 and indeed only supports Gen1
speed (2.5 GT/s) according to lspci. PCIe r1.0 sec 7.6 prescribes the same
100 msec delay as PCIe r6.1 sec 6.6.1:
To allow components to perform internal initialization, system software
must wait for at least 100 ms from the end of a reset (cold/warm/hot)
before it is permitted to issue Configuration Requests
The behavior of the Torrent QN16e card thus appears to be a quirk. Treat
it as such and lengthen the reset delay for this specific device.
Fixes: ac91e6980563 ("PCI: Unify delay handling for reset and resume")
Link: https://lore.kernel.org/r/47727e792c7f0282dc144e3ec8ce8eb6e713394e.1695304512.git.lukas@xxxxxxxxx
Reported-by: Chad Schroeder <CSchroeder@xxxxxxxxxx>
Closes: https://lore.kernel.org/linux-pci/DM6PR16MB2844903E34CAB910082DF019B1FAA@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
Tested-by: Chad Schroeder <CSchroeder@xxxxxxxxxx>
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/quirks.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -6211,3 +6211,15 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_I
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_XILINX, 0x5020, of_pci_make_dev_node);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_XILINX, 0x5021, of_pci_make_dev_node);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_REDHAT, 0x0005, of_pci_make_dev_node);
+
+/*
+ * Devices known to require a longer delay before first config space access
+ * after reset recovery or resume from D3cold:
+ *
+ * VideoPropulsion (aka Genroco) Torrent QN16e MPEG QAM Modulator
+ */
+static void pci_fixup_d3cold_delay_1sec(struct pci_dev *pdev)
+{
+ pdev->d3cold_delay = 1000;
+}
+DECLARE_PCI_FIXUP_FINAL(0x5555, 0x0004, pci_fixup_d3cold_delay_1sec);
