From 92c45b63ce22c8898aa41806e8d6692bcd577510 Mon Sep 17 00:00:00 2001 From: Mark Tomlinson Date: Thu, 6 Aug 2020 16:14:55 +1200 Subject: PCI: Reduce warnings on possible RW1C corruption For hardware that only supports 32-bit writes to PCI there is the possibility of clearing RW1C (write-one-to-clear) bits. A rate-limited messages was introduced by fb2659230120, but rate-limiting is not the best choice here. Some devices may not show the warnings they should if another device has just produced a bunch of warnings. Also, the number of messages can be a nuisance on devices which are otherwise working fine. Change the ratelimit to a single warning per bus. This ensures no bus is 'starved' of emitting a warning and also that there isn't a continuous stream of warnings. It would be preferable to have a warning per device, but the pci_dev structure is not available here, and a lookup from devfn would be far too slow. Suggested-by: Bjorn Helgaas Fixes: fb2659230120 ("PCI: Warn on possible RW1C corruption for sub-32 bit config writes") Link: https://lore.kernel.org/r/20200806041455.11070-1-mark.tomlinson@alliedtelesis.co.nz Signed-off-by: Mark Tomlinson Signed-off-by: Bjorn Helgaas Reviewed-by: Florian Fainelli Reviewed-by: Rob Herring Acked-by: Scott Branden --- include/linux/pci.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/pci.h') diff --git a/include/linux/pci.h b/include/linux/pci.h index 8253a5413d7c..678fecdf6b81 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -668,6 +668,7 @@ struct pci_bus { struct bin_attribute *legacy_io; /* Legacy I/O for this bus */ struct bin_attribute *legacy_mem; /* Legacy mem */ unsigned int is_added:1; + unsigned int unsafe_warn:1; /* warned about RW1C config write */ }; #define to_pci_bus(n) container_of(n, struct pci_bus, dev) -- cgit v1.2.3