PCI: loongson: Don't access non-existent devices

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On LS2K/LS7A, config reads to some non-existent devices don't return
0xffffffff (they are hidden devices for debug, and accessing the config
space may cause machine hang). This is a hardware flaw but we can only
avoid it by software now.

Link: https://lore.kernel.org/r/20220714124216.1489304-5-chenhuacai@loongson.cn
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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Huacai Chen 2022-07-14 20:42:13 +08:00 • committed by Bjorn Helgaas

parent cd89edda40

commit 2410e3301f

1 changed files with 23 additions and 6 deletions

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drivers/pci/controller/pci-loongson.c

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