[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20190719135301.GA685@e121166-lin.cambridge.arm.com>
Date: Fri, 19 Jul 2019 14:53:09 +0100
From: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
To: Sasha Levin <sashal@...nel.org>
Cc: linux-kernel@...r.kernel.org, stable@...r.kernel.org,
Vidya Sagar <vidyas@...dia.com>,
Thierry Reding <treding@...dia.com>, linux-pci@...r.kernel.org,
linux-tegra@...r.kernel.org
Subject: Re: [PATCH AUTOSEL 4.14 41/60] PCI: tegra: Enable Relaxed Ordering
only for Tegra20 & Tegra30
On Fri, Jul 19, 2019 at 12:10:50AM -0400, Sasha Levin wrote:
> From: Vidya Sagar <vidyas@...dia.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@...dia.com>
> [lorenzo.pieralisi@....com: completely rewrote the commit log/fixes tag]
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@....com>
> Acked-by: Thierry Reding <treding@...dia.com>
> Signed-off-by: Sasha Levin <sashal@...nel.org>
Hi Sasha,
as Jon requested, please drop this patch from the autosel patch
queue, thank you very much.
Lorenzo
> ---
> 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 1987fec1f126..d2ad76ef3e83 100644
> --- a/drivers/pci/host/pci-tegra.c
> +++ b/drivers/pci/host/pci-tegra.c
> @@ -607,12 +607,15 @@ 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_request_resources(struct tegra_pcie *pcie)
> {
> --
> 2.20.1
>
Powered by blists - more mailing lists