From: Vidya Sagar vidyas@nvidia.com
[ Upstream commit 7be142caabc4780b13a522c485abc806de5c4114 ]
The PCI Tegra controller conversion to a device tree configurable driver in commit d1523b52bff3 ("PCI: tegra: Move PCIe driver to drivers/pci/host") implied that code for the driver can be compiled in for a kernel supporting multiple platforms.
Unfortunately, a blind move of the code did not check that some of the quirks that were applied in arch/arm (eg enabling Relaxed Ordering on all PCI devices - since the quirk hook erroneously matches PCI_ANY_ID for both Vendor-ID and Device-ID) are now applied in all kernels that compile the PCI Tegra controlled driver, DT and ACPI alike.
This is completely wrong, in that enablement of Relaxed Ordering is only required by default in Tegra20 platforms as described in the Tegra20 Technical Reference Manual (available at https://developer.nvidia.com/embedded/downloads#?search=tegra%202 in Section 34.1, where it is mentioned that Relaxed Ordering bit needs to be enabled in its root ports to avoid deadlock in hardware) and in the Tegra30 platforms for the same reasons (unfortunately not documented in the TRM).
There is no other strict requirement on PCI devices Relaxed Ordering enablement on any other Tegra platforms or PCI host bridge driver.
Fix this quite upsetting situation by limiting the vendor and device IDs to which the Relaxed Ordering quirk applies to the root ports in question, reported above.
Signed-off-by: Vidya Sagar vidyas@nvidia.com [lorenzo.pieralisi@arm.com: completely rewrote the commit log/fixes tag] Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Acked-by: Thierry Reding treding@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/host/pci-tegra.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c index 8dfccf733241..6985102a4ae3 100644 --- a/drivers/pci/host/pci-tegra.c +++ b/drivers/pci/host/pci-tegra.c @@ -603,12 +603,15 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x0bf1, tegra_pcie_fixup_class); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x0e1c, tegra_pcie_fixup_class); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x0e1d, tegra_pcie_fixup_class);
-/* Tegra PCIE requires relaxed ordering */ +/* Tegra20 and Tegra30 PCIE requires relaxed ordering */ static void tegra_pcie_relax_enable(struct pci_dev *dev) { pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_RELAX_EN); } -DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, tegra_pcie_relax_enable); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, 0x0bf0, tegra_pcie_relax_enable); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, 0x0bf1, tegra_pcie_relax_enable); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, 0x0e1c, tegra_pcie_relax_enable); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, 0x0e1d, tegra_pcie_relax_enable);
static int tegra_pcie_setup(int nr, struct pci_sys_data *sys) {