On Wed, Feb 26, 2025 at 06:28:33PM +0530, Naveen Kumar P wrote: > On Wed, Feb 26, 2025 at 2:08 AM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > On Tue, Feb 25, 2025 at 06:46:02PM +0530, Naveen Kumar P wrote: > > > On Tue, Feb 25, 2025 at 1:24 AM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > > > On Tue, Feb 25, 2025 at 12:29:00AM +0530, Naveen Kumar P wrote: > > > > > On Mon, Feb 24, 2025 at 11:03 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > > > > > On Mon, Feb 24, 2025 at 05:45:35PM +0530, Naveen Kumar P wrote: > > > > > > > On Wed, Feb 19, 2025 at 10:36 PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > > > > > > > On Wed, Feb 19, 2025 at 05:52:47PM +0530, Naveen Kumar P wrote: > > > > > > > > > Hi all, > > > > > > > > > > > > > > > > > > I am writing to seek assistance with an issue we are > > > > > > > > > experiencing with a PCIe device (PLDA Device 5555) > > > > > > > > > connected through PCI Express Root Port 1 to the > > > > > > > > > host bridge. > > > > > > > > > > > > > > > > > > We have observed that after booting the system, the > > > > > > > > > Base Address Register (BAR0) memory of this device > > > > > > > > > gets reset to 0x0 after approximately one hour or > > > > > > > > > more (the timing is inconsistent). This was verified > > > > > > > > > using the lspci output and the setpci -s 01:00.0 > > > > > > > > > BASE_ADDRESS_0 command. > > > > > ... > I have downloaded the 6.13 kernel source and added additional debug > logs in hotplug_event(), then built the kernel. After that rebooted > with the new kernel using the following parameters: > BOOT_IMAGE=/vmlinuz-6.13.0+ root=/dev/mapper/vg00-rootvol ro quiet > libata.force=noncq pci=nomsi pcie_aspm=off pcie_ports=on "dyndbg=file > drivers/pci/* +p; file drivers/acpi/* +p" Why "pci=nomsi"? I don't think that should make a difference. Also, it contributes to the fact that Linux doesn't request OS control of several features that it ordinarily does, so you end up in a somewhat unusual state (which *should* still work, of course): acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig Segments HPX-Type3] acpi PNP0A08:00: _OSC: not requesting OS control; OS requires [ExtendedConfig ASPM ClockPM MSI] Same for "pcie_aspm=off". Why "pcie_ports=on"? That's not a valid parameter: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/pcie/portdrv.c?id=v6.13#n619 > Complete dmesg log and the patch(to get additional debug information) > are attached to this email. > > Any further guidance on these observations? I'm out of ideas. I would instrument the PCI config accessors to log all the reads and writes to your device (01:00.0) to see what we do to the device. Maybe there's some hint: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/access.c?id=v6.13#n35 > Additionally, I noticed that the initial bootup logs with the > "0.000000" timestamp are missing in the dmesg log with this new > kernel. I'm unsure what might be causing this issue. Probably overflowed the message buffer. You can try increasing the buffer size: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/kernel-parameters.txt?id=v6.13#n3190 You can also experiment with the dyndbg parameter to be more selective about the ACPI messages if some aren't useful. Bjorn
