for_each_child_of_node() performs an of_node_get() on each iteration, so
to break out of the loop an of_node_put() is required.
Found using Coccinelle. The semantic patch used for this is as follows:
// <smpl>
@@
expression e;
local idexpression n;
@@
for_each_child_of_node(..., n) {
... when != of_node_put(n)
when != e = n
(
return n;
|
+ of_node_put(n);
? return ...;
)
...
}
// </smpl>
Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
for_each_child_of_node() performs an of_node_put() on each iteration, so
putting an of_node_put() before a continue results in a double put.
The semantic match that finds this problem is as follows
(http://coccinelle.lip6.fr):
// <smpl>
@@
expression root,e;
local idexpression child;
iterator name for_each_child_of_node;
@@
for_each_child_of_node(root, child) {
... when != of_node_get(child)
* of_node_put(child);
...
* continue;
}
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Recent versions of the Tegra MC hardware extend the size of the client
ID bitfield in the MC_ERR_STATUS register by one bit. While one could
simply extend the bitfield for older hardware, that would allow data
from reserved bits into the driver code, which is generally a bad idea
on principle. So this patch instead passes in the client ID mask from
from the per-SoC MC data.
There's no MC support for T210 (yet), but when that support winds up
in the kernel, the appropriate soc->client_id_mask value for that chip
will be 0xff.
Based on an original patch by David Ung <davidu@nvidia.com>.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: David Ung <davidu@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The EMC driver needs to know the number of external memory devices and
also needs to update the EMEM configuration based on the new rate of the
memory bus.
To know how to update the EMEM config, looks up the values of the burst
regs in the DT, for a given timing.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
As this interrupt is just for development purposes, as the TRM says, and
the sheer amount of interrupts fired can seriously disrupt userspace
when testing the lower frequencies supported by the EMC.
From the TRM:
"There is one performance warning type interrupt: ARBITRATION_EMEM. It
fires when the MC detects that a request has been pending in the Row
Sorter long enough to hit the DEADLOCK_PREVENTION_SLACK_THRESHOLD. In
addition to true performance problems, this interrupt may fire in
situations such as clock-change where the EMC backpressures pending
traffic for long periods of time. This interrupt helps developers
identify and debug performance issues and configuration issues."
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The memory controller on Tegra132 is very similar to the one found on
Tegra124. But the Denver CPUs don't have an outer cache, so dcache
maintenance is done slightly differently.
Signed-off-by: Thierry Reding <treding@nvidia.com>
The memory controller on NVIDIA Tegra exposes various knobs that can be
used to tune the behaviour of the clients attached to it.
Currently this driver sets up the latency allowance registers to the HW
defaults. Eventually an API should be exported by this driver (via a
custom API or a generic subsystem) to allow clients to register latency
requirements.
This driver also registers an IOMMU (SMMU) that's implemented by the
memory controller. It is supported on Tegra30, Tegra114 and Tegra124
currently. Tegra20 has a GART instead.
The Tegra SMMU operates on memory clients and SWGROUPs. A memory client
is a unidirectional, special-purpose DMA master. A SWGROUP represents a
set of memory clients that form a logical functional unit corresponding
to a single device. Typically a device has two clients: one client for
read transactions and one client for write transactions, but there are
also devices that have only read clients, but many of them (such as the
display controllers).
Because there is no 1:1 relationship between memory clients and devices
the driver keeps a table of memory clients and the SWGROUPs that they
belong to per SoC. Note that this is an exception and due to the fact
that the SMMU is tightly integrated with the rest of the Tegra SoC. The
use of these tables is discouraged in drivers for generic IOMMU devices
such as the ARM SMMU because the same IOMMU could be used in any number
of SoCs and keeping such tables for each SoC would not scale.
Acked-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Amitoj Kaur Chawla