[PATCH 0/2] PCI: Fix the PCIe bridge decreasing to Gen 1 during

From: Jiwei Sun
Date: Fri Jan 10 2025 - 08:25:32 EST


From: Jiwei Sun <sunjw10@xxxxxxxxxx>

When we do the quick hot-add/hot-remove test with a PCIE Gen 5 NVMe disk,
there is a possibility that the PCIe bridge will decrease to 2.5GT/s from
32GT/s.

The issue is caused by commit a89c82249c37 ("PCI: Work around PCIe link
training failures"). Although the commit 712e49c96706 ("PCI: Correct error
reporting with PCIe failed link retraining") and the commit f68dea13405c
("PCI: Revert to the original speed after PCIe failed link retraining")
have tried to fix the similar issue. However, there is still a window for
triggering the issue within 1-second hot-add/hot-remove test.

Besides, the commit de9a6c8d5dbf ("PCI/bwctrl: Add pcie_set_target_speed()
introduces two potential issues might cause that the removing 2.5GT/s
downstream link speed restriction works fail.

Jiwei Sun (2):
PCI: Fix the wrong reading of register fields
PCI: Fix the PCIe bridge decreasing to Gen 1 during hotplug testing

drivers/pci/quirks.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

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2.34.1