Each iteration of for_each_child_of_node() executes of_node_put() on the
previous node, but in some return paths in the middle of the loop
of_node_put() is missing thus causing a reference leak.
Hence stash these mid-loop return values in a variable 'err' and add a
new label err_node_put which executes of_node_put() on the previous node
and returns 'err' on failure.
Change mid-loop return statements to point to jump to this label to
fix the reference leak.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
[lorenzo.pieralisi@arm.com: rewrote commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
The PCI Tegra controller conversion to a device tree configurable
driver in commit d1523b52bf ("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>
Driver checks for link up three times before giving up, each retry
attempt is printed as an error. Letting users know that PCIe link is
down and in the process of being brought up again is for debug, not an
error condition.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tegra PCIe has fixed per port SFIO line to signal PERST#, which can be
controlled by AFI port register. However, if a platform routes a
different GPIO to the PCIe slot, then port register cannot control it.
Add support for GPIO based PERST# signal for such platforms. GPIO number
comes from per port PCIe device tree node. PCIe driver probe doesn't
fail if per port "reset-gpios" property is not populated, so platforms
that require this workaround must make sure that the DT property is not
missed in the corresponding device tree.
Link: https://lore.kernel.org/linux-pci/20190705084850.30777-1-jonathanh@nvidia.com/
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
[lorenzo.pieralisi@arm.com: squashed in fix in Link]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
In Tegra210 AFI design has clamp value for the BIAS pad as 0, which keeps
the bias pad in non power down mode. This is leading to power consumption
of 2 mW in BIAS pad, even if the PCIe partition is powergated. To avoid
unnecessary power consumption, put PEX CLK & BIAS pads in deep power down
mode when PCIe partition is power gated.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tegra186 and Tegra30 have three PCIe root ports. AFI_PEX2_CTRL register
is defined for third root port. Offset of this register in Tegra186 is
different from Tegra30, so add the offset as part of SoC data structure.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
PRSNT_MAP bit field is programmed to update the slot present status.
PRSNT_SENSE IRQ is triggered when this bit field is programmed, which is
not an error. Add a new if condition to trap PRSNT_SENSE code and print
it with debug log level.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Cacheable upstream transactions are supported in Tegra20 and Tegra186
only.
AFI_CACHE_BAR_{0,1}_{ST,SZ} registers are available in Tegra20 to
support cacheable upstream transactions. In Tegra186, AFI_AXCACHE
register is defined instead of AFI_CACHE_BAR_{0,1}_{ST,SZ} to be in line
with its memory subsystem design.
Therefore, program AFI_CACHE_BAR_{0,1}_{ST,SZ} registers only for Tegra20.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Disable controllers which failed to bring the link up and configure
CLKREQ# signals of these controllers as GPIO. This is required to avoid
CLKREQ# signal of inactive controllers interfering with PLLE power down
sequence.
PCIE_CLKREQ_GPIO bits are defined only in Tegra186, however programming
these bits in other SoCs doesn't cause any side effects. Program these
bits for all Tegra SoCs to avoid a conditional check.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
PCIe link up fails with few legacy endpoints if root port advertises both
Gen-1 and Gen-2 speeds in Tegra. This is because link number negotiation
fails if both Gen1 & Gen2 are advertised. Tegra doesn't retry link up by
advertising only Gen1. Hence, the strategy followed here is to initially
advertise only Gen-1 and after link is up, retrain link to Gen-2 speed.
Tegra doesn't support HW autonomous speed change. Link comes up in Gen1
even if Gen2 is advertised, so there is no downside of this change.
This behavior is observed with following two PCIe devices on Tegra:
- Fusion HDTV 5 Express card
- IOGear SIL - PCIE - SATA card
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Recommended UpdateFC threshold in Tegra210 is 0x60 for best performance
of x1 link. Setting this to 0x60 provides the best balance between number
of UpdateFC packets and read data sent over the link.
UpdateFC timer frequency is equal to twice the value of register content
in nsec, i.e (2 * 0x60) = 192 nsec.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
The logic which blocks read requests till AFI gets ACK for all outstanding
writes from memory controller does not behave correctly when number of
outstanding writes become more than 32 in Tegra124 and Tegra132.
SW fixup is to prevent writes from accumulating more than 32 by:
- limiting outstanding posted writes to 14
- modifying Gen1 and Gen2 UpdateFC timer frequency
UpdateFC timer frequency is equal to twice the value of register content
in nsec. These settings are recommended after stress testing with
different values.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Sometimes link speed change from Gen2 to Gen1 fails due to instability
in deskew logic on lane-0 in Tegra210. Increase the deskew retry time
to resolve this issue.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Enable xclk clock clamping when entering L1. Clamp threshold will
determine the time spent waiting for clock module to turn on xclk after
signaling it. Default threshold value in Tegra124 and Tegra210 is not
enough to turn on xclk clock. Increase the clamp threshold to meet the
clock module timing in Tegra124 and Tegra210. Default threshold value is
enough in Tegra20, Tegra30 and Tegra186.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
PM message are truncated while entering L1 or L2, which is resulting in
receiver errors. Set the required bit to finish processing DLLP before
link enter L1 or L2.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Outstanding write counter in AFI is used to generate idle signal to
dynamically gate the AFI clock. When there are 32 outstanding writes
from AFI to memory, the outstanding write counter overflows and
indicates that there are "0" outstanding write transactions.
When memory controller is under heavy load, write completions to AFI
gets delayed and AFI write counter overflows. This causes AFI clock gating
even when there are outstanding transactions towards memory controller
resulting in a system hang.
Disable dynamic clock gating of AFI clock to avoid system hang.
CLKEN_OVERRIDE bit is not defined in Tegra20 and Tegra30, however
programming this bit doesn't cause any side effects. Program this
bit for all Tegra SoCs to avoid conditional check.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Enable opportunistic UpdateFC and ACK to allow data link layer send
pending ACKs and UpdateFC packets when link is idle instead of waiting
for timers to expire. This improves the PCIe performance due to better
utilization of PCIe bandwidth.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
UPHY electrical programming guidelines are documented in Tegra210 TRM.
Program these electrical settings for proper eye diagram in Gen1 and Gen2
link speeds.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Default root port setting hides AER capability. This patch enables the
advertisement of AER capability by root port.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tegra124, Tegra132, Tegra210 and Tegra186 support Gen2 link speed. After
PCIe link is up in Gen1, set target link speed as Gen2 and retrain link.
Link switches to Gen2 speed if Gen2 capable end point is connected,
otherwise the link stays in Gen1.
Per PCIe 4.0r0.9 sec 7.6.3.7 implementation note, driver needs to wait for
PCIe LTSSM to come back from recovery before retraining the link.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
The PCIe host power up sequence requires to program AFI(AXI to FPCI
bridge) registers first and then PCIe registers, otherwise AFI register
settings may not latch to PCIe IP.
PCIe root port starts LTSSM as soon as PCIe xrst is deasserted.
So deassert PCIe xrst after programming PCIe registers.
Modify PCIe power up sequence as follows:
- Power ungate PCIe partition
- Enable AFI clock
- Deassert AFI reset
- Program AFI registers
- Enable PCIe clock
- Deassert PCIe reset
- Program PCIe PHY
- Program PCIe pad control registers
- Program PCIe root port registers
- Deassert PCIe xrst to start LTSSM
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tegra PCIe has register specifications for:
- AXI to FPCI(AFI) bridge
- Multiple PCIe root ports
- PCIe PHY
- PCIe pad control
Rearrange Tegra PCIe driver functions so that each function programs
the required module only.
- tegra_pcie_enable_controller(): Program AFI module and enable PCIe
controller
- tegra_pcie_phy_power_on(): Bring up PCIe PHY
- tegra_pcie_apply_pad_settings(): Program PCIe REFCLK pad settings
- tegra_pcie_enable_ports(): Program each root port and bring up PCIe
link
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Unroll the PCIe power on sequence if any one of the steps fails in
tegra_pcie_power_on().
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Since the upstream MSI memory writes are generated by downstream
devices, it is logically correct to have MSI target memory coming from
the DMA pool reserved for PCIe than from the general memory pool
reserved for CPU access to avoid PCIe DMA addresses coinciding with
MSI target address thereby raising unwanted MSI interrupts.
Enforce this behaviour by retrieving the MSI address through the DMA
API.
Limit the MSI target address to 32-bits to make it work for PCIe
endpoints that support only 32-bit MSI target address; endpoints that
support 64-bit MSI target address work with 32-bit MSI target
address too.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Native PCI drivers for root complex devices were originally all in
drivers/pci/host/. Some of these devices can also be operated in endpoint
mode. Drivers for endpoint mode didn't seem to fit in the "host"
directory, so we put both the root complex and endpoint drivers in
per-device directories, e.g., drivers/pci/dwc/, drivers/pci/cadence/, etc.
These per-device directories contain trivial Kconfig and Makefiles and
clutter drivers/pci/. Make a new drivers/pci/controllers/ directory and
collect all the device-specific drivers there.
No functional change intended.
Link: https://lkml.kernel.org/r/1520304202-232891-1-git-send-email-shawn.lin@rock-chips.com
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Nishka Dasgupta