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")
Closes: https://lore.kernel.org/linux-pci/DM6PR16MB2844903E34CAB910082DF019B1FAA@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
Reported-by: Chad Schroeder <CSchroeder@xxxxxxxxxx>
Tested-by: Chad Schroeder <CSchroeder@xxxxxxxxxx>
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.4+
---
drivers/pci/quirks.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index eeec1d6f9023..91a15d79c7c4 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -6188,3 +6188,15 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a31, dpc_log_size);
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);
--
2.40.1
