On 09/08/2022 22:21, Bjorn Helgaas wrote: > [+cc regressions list] > > 23d99baf9d72 appeared in v5.19-rc1. > > On Tue, Aug 09, 2022 at 11:29:43AM -0700, Stephen Hemminger wrote: >> This commit broke the driver override script in DPDK. >> This is an API/ABI breakage, please revert or fix the commit. >> >> Report of problem: >> http://mails.dpdk.org/archives/dev/2022-August/247794.html Thanks for the report. I'll take a look. >> >> >> commit 23d99baf9d729ca30b2fb6798a7b403a37bfb800 >> Author: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >> Date: Tue Apr 19 13:34:28 2022 +0200 >> >> PCI: Use driver_set_override() instead of open-coding >> >> Use a helper to set driver_override to the reduce amount of duplicated >> code. Make the driver_override field const char, because it is not >> modified by the core and it matches other subsystems. >> >> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> >> Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> >> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >> Link: https://lore.kernel.org/r/20220419113435.246203-6-krzysztof.kozlowski@xxxxxxxxxx >> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> >> >> >> The script is sending single nul character to remove override >> and that no longer works. The sysfs API clearly states: "and may be cleared with an empty string (echo > driver_override)." Documentation/ABI/testing/sysfs-bus-pci Sending other data and expecting the same result is not conforming to API. Therefore we have usual example of some undocumented behavior which user-space started relying on and instead using API, user-space expect that undocumented behavior to be back. Yay! I wonder what is the point to even describe the ABI if user-space can simply ignore it? Best regards, Krzysztof
