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authorDave Airlie <airlied@redhat.com>2021-04-07 09:32:05 +0200
committerDave Airlie <airlied@redhat.com>2021-04-07 09:32:12 +0200
commit1539f71602edf09bb33666afddc5a781c42e768d (patch)
tree7cdfad1e08b3d58acee56659de1f64f3bd2b1697 /Documentation
parentMerge tag 'exynos-drm-next-for-v5.13' of git://git.kernel.org/pub/scm/linux/k... (diff)
parentdrm/bridge: anx7625: disable regulators when power off (diff)
downloadlinux-1539f71602edf09bb33666afddc5a781c42e768d.tar.xz
linux-1539f71602edf09bb33666afddc5a781c42e768d.zip
Merge tag 'drm-misc-next-2021-04-01' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
drm-misc-next for 5.13: UAPI Changes: Cross-subsystem Changes: Core Changes: - mst: Improve topology logging - edid: Rework and improvements for displayid Driver Changes: - anx7625: Regulators support - bridge: Support for the Chipone ICN6211, Lontium LT8912B - lt9611: Fix 4k panels handling Signed-off-by: Dave Airlie <airlied@redhat.com> From: Maxime Ripard <maxime@cerno.tech> Link: https://patchwork.freedesktop.org/patch/msgid/20210401110552.2b3yetlgsjtlotcn@gilmour
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml15
-rw-r--r--Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml99
-rw-r--r--Documentation/devicetree/bindings/display/bridge/lontium,lt8912b.yaml102
-rw-r--r--Documentation/devicetree/bindings/display/panel/panel-simple.yaml2
-rw-r--r--Documentation/driver-api/dma-buf.rst76
-rw-r--r--Documentation/gpu/todo.rst2
6 files changed, 295 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml b/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml
index c789784efe30..ab48ab2f4240 100644
--- a/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml
@@ -34,6 +34,15 @@ properties:
description: used for reset chip control, RESET_N pin B7.
maxItems: 1
+ vdd10-supply:
+ description: Regulator that provides the supply 1.0V power.
+
+ vdd18-supply:
+ description: Regulator that provides the supply 1.8V power.
+
+ vdd33-supply:
+ description: Regulator that provides the supply 3.3V power.
+
ports:
$ref: /schemas/graph.yaml#/properties/ports
@@ -55,6 +64,9 @@ properties:
required:
- compatible
- reg
+ - vdd10-supply
+ - vdd18-supply
+ - vdd33-supply
- ports
additionalProperties: false
@@ -72,6 +84,9 @@ examples:
reg = <0x58>;
enable-gpios = <&pio 45 GPIO_ACTIVE_HIGH>;
reset-gpios = <&pio 73 GPIO_ACTIVE_HIGH>;
+ vdd10-supply = <&pp1000_mipibrdg>;
+ vdd18-supply = <&pp1800_mipibrdg>;
+ vdd33-supply = <&pp3300_mipibrdg>;
ports {
#address-cells = <1>;
diff --git a/Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml b/Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml
new file mode 100644
index 000000000000..62c3bd4cb28d
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml
@@ -0,0 +1,99 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/chipone,icn6211.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Chipone ICN6211 MIPI-DSI to RGB Converter bridge
+
+maintainers:
+ - Jagan Teki <jagan@amarulasolutions.com>
+
+description: |
+ ICN6211 is MIPI-DSI to RGB Converter bridge from chipone.
+
+ It has a flexible configuration of MIPI DSI signal input and
+ produce RGB565, RGB666, RGB888 output format.
+
+properties:
+ compatible:
+ enum:
+ - chipone,icn6211
+
+ reg:
+ maxItems: 1
+ description: virtual channel number of a DSI peripheral
+
+ enable-gpios:
+ description: Bridge EN pin, chip is reset when EN is low.
+
+ vdd1-supply:
+ description: A 1.8V/2.5V/3.3V supply that power the MIPI RX.
+
+ vdd2-supply:
+ description: A 1.8V/2.5V/3.3V supply that power the PLL.
+
+ vdd3-supply:
+ description: A 1.8V/2.5V/3.3V supply that power the RGB output.
+
+ ports:
+ $ref: /schemas/graph.yaml#/properties/ports
+
+ properties:
+ port@0:
+ $ref: /schemas/graph.yaml#/properties/port
+ description:
+ Video port for MIPI DSI input
+
+ port@1:
+ $ref: /schemas/graph.yaml#/properties/port
+ description:
+ Video port for MIPI DPI output (panel or connector).
+
+ required:
+ - port@0
+ - port@1
+
+required:
+ - compatible
+ - reg
+ - enable-gpios
+ - ports
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ dsi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ bridge@0 {
+ compatible = "chipone,icn6211";
+ reg = <0>;
+ enable-gpios = <&r_pio 0 5 GPIO_ACTIVE_HIGH>; /* LCD-RST: PL5 */
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+
+ bridge_in_dsi: endpoint {
+ remote-endpoint = <&dsi_out_bridge>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ bridge_out_panel: endpoint {
+ remote-endpoint = <&panel_out_bridge>;
+ };
+ };
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/display/bridge/lontium,lt8912b.yaml b/Documentation/devicetree/bindings/display/bridge/lontium,lt8912b.yaml
new file mode 100644
index 000000000000..735d0233a7d6
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/lontium,lt8912b.yaml
@@ -0,0 +1,102 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/lontium,lt8912b.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Lontium LT8912B MIPI to HDMI Bridge
+
+maintainers:
+ - Adrien Grassein <adrien.grassein@gmail.com>
+
+description: |
+ The LT8912B is a bridge device which convert DSI to HDMI
+
+properties:
+ compatible:
+ enum:
+ - lontium,lt8912b
+
+ reg:
+ maxItems: 1
+
+ reset-gpios:
+ maxItems: 1
+ description: GPIO connected to active high RESET pin.
+
+ ports:
+ $ref: /schemas/graph.yaml#/properties/ports
+
+ properties:
+ port@0:
+ $ref: /schemas/graph.yaml#/properties/port
+ description:
+ Primary MIPI port for MIPI input
+
+ properties:
+ endpoint:
+ $ref: /schemas/media/video-interfaces.yaml#
+ unevaluatedProperties: false
+
+ properties:
+ data-lanes: true
+
+ required:
+ - data-lanes
+
+ port@1:
+ $ref: /schemas/graph.yaml#/properties/port
+ description: |
+ HDMI port, should be connected to a node compatible with the
+ hdmi-connector binding.
+
+ required:
+ - port@0
+ - port@1
+
+required:
+ - compatible
+ - reg
+ - reset-gpios
+ - ports
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ i2c4 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ hdmi-bridge@48 {
+ compatible = "lontium,lt8912b";
+ reg = <0x48>;
+ reset-gpios = <&max7323 0 GPIO_ACTIVE_LOW>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+
+ hdmi_out_in: endpoint {
+ data-lanes = <0 1 2 3>;
+ remote-endpoint = <&mipi_dsi_out>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ endpoint {
+ remote-endpoint = <&hdmi_in>;
+ };
+ };
+ };
+ };
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
index 62b0d54d87b7..b3797ba2698b 100644
--- a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
+++ b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
@@ -161,6 +161,8 @@ properties:
# Innolux Corporation 12.1" G121X1-L03 XGA (1024x768) TFT LCD panel
- innolux,g121x1-l03
# Innolux Corporation 11.6" WXGA (1366x768) TFT LCD panel
+ - innolux,n116bca-ea1
+ # Innolux Corporation 11.6" WXGA (1366x768) TFT LCD panel
- innolux,n116bge
# InnoLux 13.3" FHD (1920x1080) eDP TFT LCD panel
- innolux,n125hce-gn1
diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst
index a2133d69872c..7f37ec30d9fd 100644
--- a/Documentation/driver-api/dma-buf.rst
+++ b/Documentation/driver-api/dma-buf.rst
@@ -257,3 +257,79 @@ fences in the kernel. This means:
userspace is allowed to use userspace fencing or long running compute
workloads. This also means no implicit fencing for shared buffers in these
cases.
+
+Recoverable Hardware Page Faults Implications
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Modern hardware supports recoverable page faults, which has a lot of
+implications for DMA fences.
+
+First, a pending page fault obviously holds up the work that's running on the
+accelerator and a memory allocation is usually required to resolve the fault.
+But memory allocations are not allowed to gate completion of DMA fences, which
+means any workload using recoverable page faults cannot use DMA fences for
+synchronization. Synchronization fences controlled by userspace must be used
+instead.
+
+On GPUs this poses a problem, because current desktop compositor protocols on
+Linux rely on DMA fences, which means without an entirely new userspace stack
+built on top of userspace fences, they cannot benefit from recoverable page
+faults. Specifically this means implicit synchronization will not be possible.
+The exception is when page faults are only used as migration hints and never to
+on-demand fill a memory request. For now this means recoverable page
+faults on GPUs are limited to pure compute workloads.
+
+Furthermore GPUs usually have shared resources between the 3D rendering and
+compute side, like compute units or command submission engines. If both a 3D
+job with a DMA fence and a compute workload using recoverable page faults are
+pending they could deadlock:
+
+- The 3D workload might need to wait for the compute job to finish and release
+ hardware resources first.
+
+- The compute workload might be stuck in a page fault, because the memory
+ allocation is waiting for the DMA fence of the 3D workload to complete.
+
+There are a few options to prevent this problem, one of which drivers need to
+ensure:
+
+- Compute workloads can always be preempted, even when a page fault is pending
+ and not yet repaired. Not all hardware supports this.
+
+- DMA fence workloads and workloads which need page fault handling have
+ independent hardware resources to guarantee forward progress. This could be
+ achieved through e.g. through dedicated engines and minimal compute unit
+ reservations for DMA fence workloads.
+
+- The reservation approach could be further refined by only reserving the
+ hardware resources for DMA fence workloads when they are in-flight. This must
+ cover the time from when the DMA fence is visible to other threads up to
+ moment when fence is completed through dma_fence_signal().
+
+- As a last resort, if the hardware provides no useful reservation mechanics,
+ all workloads must be flushed from the GPU when switching between jobs
+ requiring DMA fences or jobs requiring page fault handling: This means all DMA
+ fences must complete before a compute job with page fault handling can be
+ inserted into the scheduler queue. And vice versa, before a DMA fence can be
+ made visible anywhere in the system, all compute workloads must be preempted
+ to guarantee all pending GPU page faults are flushed.
+
+- Only a fairly theoretical option would be to untangle these dependencies when
+ allocating memory to repair hardware page faults, either through separate
+ memory blocks or runtime tracking of the full dependency graph of all DMA
+ fences. This results very wide impact on the kernel, since resolving the page
+ on the CPU side can itself involve a page fault. It is much more feasible and
+ robust to limit the impact of handling hardware page faults to the specific
+ driver.
+
+Note that workloads that run on independent hardware like copy engines or other
+GPUs do not have any impact. This allows us to keep using DMA fences internally
+in the kernel even for resolving hardware page faults, e.g. by using copy
+engines to clear or copy memory needed to resolve the page fault.
+
+In some ways this page fault problem is a special case of the `Infinite DMA
+Fences` discussions: Infinite fences from compute workloads are allowed to
+depend on DMA fences, but not the other way around. And not even the page fault
+problem is new, because some other CPU thread in userspace might
+hit a page fault which holds up a userspace fence - supporting page faults on
+GPUs doesn't anything fundamentally new.
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 1b4b64b71c7e..7ff9fac10d8b 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -677,7 +677,7 @@ Outside DRM
Convert fbdev drivers to DRM
----------------------------
-There are plenty of fbdev drivers for older hardware. Some hwardware has
+There are plenty of fbdev drivers for older hardware. Some hardware has
become obsolete, but some still provides good(-enough) framebuffers. The
drivers that are still useful should be converted to DRM and afterwards
removed from fbdev.