On Sat, 27 Aug 2022 at 06:30, Pali Rohár pali@kernel.org wrote:
PCIe GEN3 link retrain workaround, specially designed for system with PCIe ASMedia ASM2824 Switch and other Endpoint devices, unconditionally increase size of all SPL binaries with PCIe support, even those which do not require it.
Moreover this workaround is enabled for all existing hardware and also all future PCIe hardware, which opens a hole that other PCIe vendors may introduce same HW issue as on systems where this workaround is required and nobody would notice it because U-Boot automatically apply workaround for it.
So do not unconditionally enable this workaround on all hardware. Instead introduce a new config option which is disabled by default. This decrease SPL size and also ensure that workaround is not blindly or inexactly enabled.
To make workaround code local, move it into separate file, so pci_auto.c contains only generic auto configuration code.
Signed-off-by: Pali Rohár pali@kernel.org
Changes in v2:
- Rename config option to CONFIG_PCIE_GEN3_RETRAIN_WORKAROUND as it is generic workaround and does not have to be needed only for ASMedia switch (moreover it looks like issue is triggered by combination of ASMedia switch with other endpoint PCIe device)
- Rephrase Kconfig help text as suggected by Stefan
drivers/pci/Kconfig | 9 + drivers/pci/Makefile | 1 + drivers/pci/pci_auto.c | 171 +------------------ drivers/pci/pcie_gen3_retrain_workaround.c | 183 +++++++++++++++++++++ 4 files changed, 197 insertions(+), 167 deletions(-) create mode 100644 drivers/pci/pcie_gen3_retrain_workaround.c
Reviewed-by: Simon Glass sjg@chromium.org