On Wed, Aug 16, 2023 at 03:27:53PM -0700, Sam Edwards wrote: > When the Broadcom STB PCIe controller is initialized, it must be set > into one of three CLKREQ# modes: "none"/"aspm"/"l1ss". The Linux driver, > through today, hard-codes "aspm" since the vast majority of boards using > this driver have a fixed PCIe bus with the CLKREQ# signal wired up. > > The Raspberry Pi CM4, however, can be connected to a plethora of PCIe > devices, some of which do not connect the CLKREQ# line (they just leave > it floating). So "aspm" mode is no longer appropriate in all cases. In > Linux, there is a proposed patchset [1] to determine the proper mode. > This doesn't really make sense in U-Boot's case, so we just change the > assumption from "aspm" to "none" (which is always safe). > > This patch DOES resolve a real-world crash that occurs when U-Boot is > running on a Raspberry Pi CM4 installed in slot 3 of a Turing Pi 2 > cluster board. > > [1]: https://lore.kernel.org/all/20230428223500.23337-1-jim2101...@gmail.com/ > > Signed-off-by: Sam Edwards <cfswo...@gmail.com>
Applied to u-boot/next, thanks! -- Tom
signature.asc
Description: PGP signature
