From ca230ab18791f418faac19d00f3c35e2dbc25dfe Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Wed, 20 Jan 2021 09:59:22 -0800 Subject: dt-bindings: dp-connector: Drop maxItems from -supply The meta-schema recently gained a definition for the common -supply$ property, which denotes that maxItems is not a valid property. Drop this to clear up the binding validation error. Fixes: a46c112512de ("dt-bindings: dp-connector: add binding for DisplayPort connector") Signed-off-by: Bjorn Andersson Signed-off-by: Rob Herring Link: https://patchwork.freedesktop.org/patch/msgid/20210120175922.1579835-1-bjorn.andersson@linaro.org --- Documentation/devicetree/bindings/display/connector/dp-connector.yaml | 1 - 1 file changed, 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/display/connector/dp-connector.yaml b/Documentation/devicetree/bindings/display/connector/dp-connector.yaml index 1c17d60e7760..22792a79e7ce 100644 --- a/Documentation/devicetree/bindings/display/connector/dp-connector.yaml +++ b/Documentation/devicetree/bindings/display/connector/dp-connector.yaml @@ -26,7 +26,6 @@ properties: dp-pwr-supply: description: Power supply for the DP_PWR pin - maxItems: 1 port: $ref: /schemas/graph.yaml#/properties/port -- cgit From 6a56d09bdab7c9d17ca2cf70c62ec162bbb972f7 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Thu, 21 Jan 2021 12:29:19 +0100 Subject: drm: Update todo.rst Internship season is starting, let's review this. One thing that's pending is Maxime's work to roll out drm_atomic_state pointers to all callbacks, he said he'll remove that entry once it's all done. v2: Fix typos (Maxime) Acked-by: Maxime Ripard Signed-off-by: Daniel Vetter Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210121112919.1460322-1-daniel.vetter@ffwll.ch --- Documentation/gpu/todo.rst | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) (limited to 'Documentation') diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 009d8e6c7e3c..dea9082c0e5f 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -577,20 +577,24 @@ Contact: Daniel Vetter Level: Intermediate -KMS cleanups ------------- +Object lifetime fixes +--------------------- + +There's two related issues here + +- Cleanup up the various ->destroy callbacks, which often are all the same + simple code. -Some of these date from the very introduction of KMS in 2008 ... +- Lots of drivers erroneously allocate DRM modeset objects using devm_kzalloc, + which results in use-after free issues on driver unload. This can be serious + trouble even for drivers for hardware integrated on the SoC due to + EPROBE_DEFERRED backoff. -- Make ->funcs and ->helper_private vtables optional. There's a bunch of empty - function tables in drivers, but before we can remove them we need to make sure - that all the users in helpers and drivers do correctly check for a NULL - vtable. +Both these problems can be solved by switching over to drmm_kzalloc(), and the +various convenience wrappers provided, e.g. drmm_crtc_alloc_with_planes(), +drmm_universal_plane_alloc(), ... and so on. -- Cleanup up the various ->destroy callbacks. A lot of them just wrapt the - drm_*_cleanup implementations and can be removed. Some tack a kfree() at the - end, for which we could add drm_*_cleanup_kfree(). And then there's the (for - historical reasons) misnamed drm_primary_helper_destroy() function. +Contact: Daniel Vetter Level: Intermediate @@ -626,8 +630,6 @@ See the documentation of :ref:`VKMS ` for more details. This is an ideal internship task, since it only requires a virtual machine and can be sized to fit the available time. -Contact: Daniel Vetter - Level: See details Backlight Refactoring -- cgit From 3b1b42fde9113e8c9cb6ba8a1648f8c140924561 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Sat, 16 Jan 2021 00:23:02 +0200 Subject: dt-bindings: display: mxsfb: Convert binding to YAML Convert the mxsfb binding to YAML. The deprecated binding is dropped, as neither the DT sources nor the driver support it anymore. The converted binding is named fsl,lcdif.yaml to match the usual bindings naming scheme. The compatible strings are messy, and DT sources use different kinds of combination of documented and undocumented values. Keep it simple for now, and update the example to make it valid. Aligning the binding with the existing DT sources will be performed separately. Signed-off-by: Laurent Pinchart Reviewed-by: Sam Ravnborg Reviewed-by: Rob Herring Signed-off-by: Rob Herring Link: https://patchwork.freedesktop.org/patch/msgid/20210115222304.5427-2-laurent.pinchart@ideasonboard.com --- .../devicetree/bindings/display/fsl,lcdif.yaml | 101 +++++++++++++++++++++ .../devicetree/bindings/display/mxsfb.txt | 87 ------------------ 2 files changed, 101 insertions(+), 87 deletions(-) create mode 100644 Documentation/devicetree/bindings/display/fsl,lcdif.yaml delete mode 100644 Documentation/devicetree/bindings/display/mxsfb.txt (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml new file mode 100644 index 000000000000..bbd47d80d253 --- /dev/null +++ b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml @@ -0,0 +1,101 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/display/fsl,lcdif.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Freescale/NXP i.MX LCD Interface (LCDIF) + +maintainers: + - Marek Vasut + - Stefan Agner + +description: | + (e)LCDIF display controller found in the Freescale/NXP i.MX SoCs. + +properties: + compatible: + enum: + - fsl,imx23-lcdif + - fsl,imx28-lcdif + - fsl,imx6sx-lcdif + - fsl,imx8mq-lcdif + + reg: + maxItems: 1 + + clocks: + items: + - description: Pixel clock + - description: Bus clock + - description: Display AXI clock + minItems: 1 + + clock-names: + items: + - const: pix + - const: axi + - const: disp_axi + minItems: 1 + + interrupts: + maxItems: 1 + + port: + $ref: /schemas/graph.yaml#/properties/port + description: The LCDIF output port + +required: + - compatible + - reg + - clocks + - interrupts + - port + +additionalProperties: false + +allOf: + - if: + properties: + compatible: + contains: + const: fsl,imx6sx-lcdif + then: + properties: + clocks: + minItems: 2 + maxItems: 3 + clock-names: + minItems: 2 + maxItems: 3 + required: + - clock-names + else: + properties: + clocks: + maxItems: 1 + clock-names: + maxItems: 1 + +examples: + - | + #include + #include + + display-controller@2220000 { + compatible = "fsl,imx6sx-lcdif"; + reg = <0x02220000 0x4000>; + interrupts = ; + clocks = <&clks IMX6SX_CLK_LCDIF1_PIX>, + <&clks IMX6SX_CLK_LCDIF_APB>, + <&clks IMX6SX_CLK_DISPLAY_AXI>; + clock-names = "pix", "axi", "disp_axi"; + + port { + endpoint { + remote-endpoint = <&panel_in>; + }; + }; + }; + +... diff --git a/Documentation/devicetree/bindings/display/mxsfb.txt b/Documentation/devicetree/bindings/display/mxsfb.txt deleted file mode 100644 index c985871c46b3..000000000000 --- a/Documentation/devicetree/bindings/display/mxsfb.txt +++ /dev/null @@ -1,87 +0,0 @@ -* Freescale MXS LCD Interface (LCDIF) - -New bindings: -============= -Required properties: -- compatible: Should be "fsl,imx23-lcdif" for i.MX23. - Should be "fsl,imx28-lcdif" for i.MX28. - Should be "fsl,imx6sx-lcdif" for i.MX6SX. - Should be "fsl,imx8mq-lcdif" for i.MX8MQ. -- reg: Address and length of the register set for LCDIF -- interrupts: Should contain LCDIF interrupt -- clocks: A list of phandle + clock-specifier pairs, one for each - entry in 'clock-names'. -- clock-names: A list of clock names. For MXSFB it should contain: - - "pix" for the LCDIF block clock - - (MX6SX-only) "axi", "disp_axi" for the bus interface clock - -Required sub-nodes: - - port: The connection to an encoder chip. - -Example: - - lcdif1: display-controller@2220000 { - compatible = "fsl,imx6sx-lcdif", "fsl,imx28-lcdif"; - reg = <0x02220000 0x4000>; - interrupts = ; - clocks = <&clks IMX6SX_CLK_LCDIF1_PIX>, - <&clks IMX6SX_CLK_LCDIF_APB>, - <&clks IMX6SX_CLK_DISPLAY_AXI>; - clock-names = "pix", "axi", "disp_axi"; - - port { - parallel_out: endpoint { - remote-endpoint = <&panel_in_parallel>; - }; - }; - }; - -Deprecated bindings: -==================== -Required properties: -- compatible: Should be "fsl,imx23-lcdif" for i.MX23. - Should be "fsl,imx28-lcdif" for i.MX28. -- reg: Address and length of the register set for LCDIF -- interrupts: Should contain LCDIF interrupts -- display: phandle to display node (see below for details) - -* display node - -Required properties: -- bits-per-pixel: <16> for RGB565, <32> for RGB888/666. -- bus-width: number of data lines. Could be <8>, <16>, <18> or <24>. - -Required sub-node: -- display-timings: Refer to binding doc display-timing.txt for details. - -Examples: - -lcdif@80030000 { - compatible = "fsl,imx28-lcdif"; - reg = <0x80030000 2000>; - interrupts = <38 86>; - - display: display { - bits-per-pixel = <32>; - bus-width = <24>; - - display-timings { - native-mode = <&timing0>; - timing0: timing0 { - clock-frequency = <33500000>; - hactive = <800>; - vactive = <480>; - hfront-porch = <164>; - hback-porch = <89>; - hsync-len = <10>; - vback-porch = <23>; - vfront-porch = <10>; - vsync-len = <10>; - hsync-active = <0>; - vsync-active = <0>; - de-active = <1>; - pixelclk-active = <0>; - }; - }; - }; -}; -- cgit From 5d16e40dd70298f8e35c727df56a05a49326c044 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Sat, 16 Jan 2021 00:23:03 +0200 Subject: dt-bindings: display: mxsfb: Add and fix compatible strings Additional compatible strings have been added in DT source for the i.MX6SL, i.MX6SLL, i.MX6UL and i.MX7D without updating the bindings. Most of the upstream DT sources use the fsl,imx28-lcdif compatible string, which mostly predates the realization that the LCDIF in the i.MX6 and newer SoCs have extra features compared to the i.MX28. Update the bindings to add the missing compatible strings, with the correct fallback values. This fails to validate some of the upstream DT sources. Instead of adding the incorrect compatible fallback to the binding, the sources should be updated separately. Signed-off-by: Laurent Pinchart Reviewed-by: Sam Ravnborg Reviewed-by: Rob Herring Signed-off-by: Rob Herring Link: https://patchwork.freedesktop.org/patch/msgid/20210115222304.5427-3-laurent.pinchart@ideasonboard.com --- .../devicetree/bindings/display/fsl,lcdif.yaml | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml index bbd47d80d253..4fc24d482b1c 100644 --- a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml +++ b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml @@ -15,11 +15,19 @@ description: | properties: compatible: - enum: - - fsl,imx23-lcdif - - fsl,imx28-lcdif - - fsl,imx6sx-lcdif - - fsl,imx8mq-lcdif + oneOf: + - enum: + - fsl,imx23-lcdif + - fsl,imx28-lcdif + - fsl,imx6sx-lcdif + - items: + - enum: + - fsl,imx6sl-lcdif + - fsl,imx6sll-lcdif + - fsl,imx6ul-lcdif + - fsl,imx7d-lcdif + - fsl,imx8mq-lcdif + - const: fsl,imx6sx-lcdif reg: maxItems: 1 -- cgit From 25e524bfbda19b3d9c7fdb234e3fe2fba10e28f7 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Sat, 16 Jan 2021 00:23:04 +0200 Subject: dt-bindings: display: mxsfb: Add compatible for i.MX8MM NXP's i.MX8MM has an LCDIF as well. Signed-off-by: Marek Vasut Reviewed-by: Laurent Pinchart Signed-off-by: Laurent Pinchart Signed-off-by: Rob Herring Link: https://patchwork.freedesktop.org/patch/msgid/20210115222304.5427-4-laurent.pinchart@ideasonboard.com --- Documentation/devicetree/bindings/display/fsl,lcdif.yaml | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml index 4fc24d482b1c..a4c3064c778c 100644 --- a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml +++ b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml @@ -26,6 +26,7 @@ properties: - fsl,imx6sll-lcdif - fsl,imx6ul-lcdif - fsl,imx7d-lcdif + - fsl,imx8mm-lcdif - fsl,imx8mq-lcdif - const: fsl,imx6sx-lcdif -- cgit From e7cbc68a28e14c51e354f94831bd03cdf7ec6cea Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Mon, 11 Jan 2021 15:23:07 +0100 Subject: dt-binding: display: bcm2711-hdmi: Add CEC and hotplug interrupts The CEC and hotplug interrupts were missing when that binding was introduced, let's add them in now that we've figured out how it works. Signed-off-by: Maxime Ripard Acked-by: Dave Stevenson Acked-by: Hans Verkuil Tested-by: Hans Verkuil Link: https://patchwork.freedesktop.org/patch/msgid/20210111142309.193441-14-maxime@cerno.tech --- .../bindings/display/brcm,bcm2711-hdmi.yaml | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml index 7ce06f9f9f8e..6e8ac910bdd8 100644 --- a/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml +++ b/Documentation/devicetree/bindings/display/brcm,bcm2711-hdmi.yaml @@ -53,6 +53,24 @@ properties: - const: audio - const: cec + interrupts: + items: + - description: CEC TX interrupt + - description: CEC RX interrupt + - description: CEC stuck at low interrupt + - description: Wake-up interrupt + - description: Hotplug connected interrupt + - description: Hotplug removed interrupt + + interrupt-names: + items: + - const: cec-tx + - const: cec-rx + - const: cec-low + - const: wakeup + - const: hpd-connected + - const: hpd-removed + ddc: allOf: - $ref: /schemas/types.yaml#/definitions/phandle @@ -90,7 +108,7 @@ required: - resets - ddc -additionalProperties: false +unevaluatedProperties: false examples: - | -- cgit From 5823cca39d585e4b4a32b1292eed0015da9c3276 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 22 Jan 2021 14:36:23 +0100 Subject: drm/todo: Add entry for moving to dma_resv_lock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Requested by Thomas. I think it justifies a new level, since I tried to make some forward progress on this last summer, and gave up (for now). This is very tricky. Acked-by: Thomas Zimmermann Signed-off-by: Daniel Vetter Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Daniel Vetter Cc: Sumit Semwal Cc: "Christian König" Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20210122133624.1751802-1-daniel.vetter@ffwll.ch --- Documentation/gpu/todo.rst | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'Documentation') diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index dea9082c0e5f..f872d3d33218 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -23,6 +23,9 @@ Advanced: Tricky tasks that need fairly good understanding of the DRM subsystem and graphics topics. Generally need the relevant hardware for development and testing. +Expert: Only attempt these if you've successfully completed some tricky +refactorings already and are an expert in the specific area + Subsystem-wide refactorings =========================== @@ -168,6 +171,22 @@ Contact: Daniel Vetter, respective driver maintainers Level: Advanced +Move Buffer Object Locking to dma_resv_lock() +--------------------------------------------- + +Many drivers have their own per-object locking scheme, usually using +mutex_lock(). This causes all kinds of trouble for buffer sharing, since +depending which driver is the exporter and importer, the locking hierarchy is +reversed. + +To solve this we need one standard per-object locking mechanism, which is +dma_resv_lock(). This lock needs to be called as the outermost lock, with all +other driver specific per-object locks removed. The problem is tha rolling out +the actual change to the locking contract is a flag day, due to struct dma_buf +buffer sharing. + +Level: Expert + Convert logging to drm_* functions with drm_device paramater ------------------------------------------------------------ -- cgit From 6dd7b6ce43acd70f75ae285fee8eeb2dd4933dce Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Mon, 8 Feb 2021 12:55:34 +0100 Subject: drm: Add additional atomic helpers for shadow-buffered planes Several drivers use GEM buffer objects as shadow buffers for the actual framebuffer memory. Right now, drivers do these vmap operations in their commit tail, which is actually not allowed by the locking rules for the dma-buf reservation lock. The involved BO has to be vmapped in the plane's prepare_fb callback and vunmapped in cleanup_fb. This patch introduces atomic helpers for such shadow planes. Plane functions manage the plane state for shadow planes. The provided implementations for prepare_fb and cleanup_fb vmap and vunmap all BOs of struct drm_plane_state.fb. The mappings are afterwards available in the plane's commit-tail functions. For now, all rsp drivers use the simple KMS helpers, so we add the plane callbacks and wrappers for simple KMS. The internal plane functions can later be exported as needed. v3: * documentation fixes v2: * make duplicate_state interface compatible with struct drm_plane_funcs Signed-off-by: Thomas Zimmermann Tested-by: Gerd Hoffmann Acked-by: Gerd Hoffmann Link: https://patchwork.freedesktop.org/patch/msgid/20210208115538.6430-4-tzimmermann@suse.de --- Documentation/gpu/drm-kms-helpers.rst | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'Documentation') diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst index b89ddd06dabb..389892f36185 100644 --- a/Documentation/gpu/drm-kms-helpers.rst +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -80,6 +80,18 @@ Atomic State Helper Reference .. kernel-doc:: drivers/gpu/drm/drm_atomic_state_helper.c :export: +GEM Atomic Helper Reference +--------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_gem_atomic_helper.c + :doc: overview + +.. kernel-doc:: include/drm/drm_gem_atomic_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_gem_atomic_helper.c + :export: + Simple KMS Helper Reference =========================== -- cgit From af612e43de6d27df51a7636229be7d33fe3ab7b5 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Tue, 16 Feb 2021 17:57:20 +0200 Subject: lib/vsprintf: Add support for printing V4L2 and DRM fourccs Add a printk modifier %p4cc (for pixel format) for printing V4L2 and DRM pixel formats denoted by fourccs. The fourcc encoding is the same for both so the same implementation can be used. Suggested-by: Mauro Carvalho Chehab Signed-off-by: Sakari Ailus Reviewed-by: Petr Mladek Reviewed-by: Sergey Senozhatsky Reviewed-by: Andy Shevchenko Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20210216155723.17109-2-sakari.ailus@linux.intel.com --- Documentation/core-api/printk-formats.rst | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'Documentation') diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst index 160e710d992f..8267675ea95c 100644 --- a/Documentation/core-api/printk-formats.rst +++ b/Documentation/core-api/printk-formats.rst @@ -567,6 +567,24 @@ For printing netdev_features_t. Passed by reference. +V4L2 and DRM FourCC code (pixel format) +--------------------------------------- + +:: + + %p4cc + +Print a FourCC code used by V4L2 or DRM, including format endianness and +its numerical value as hexadecimal. + +Passed by reference. + +Examples:: + + %p4cc BG12 little-endian (0x32314742) + %p4cc Y10 little-endian (0x20303159) + %p4cc NV12 big-endian (0xb231564e) + Thanks ====== -- cgit From c129b49825530942f344ed3e0e6a72568ad3e3e2 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Fri, 19 Feb 2021 13:00:31 +0100 Subject: drm/todo: Remove the drm_atomic_state todo item Only planes' prepare_fb and cleanup_fb, and encoders' atomic_check and atomic_mode_set hooks remain with an object state and not the global drm_atomic_state. prepare_fb and cleanup_fb operate by design on a given state and depending on the calling site can operate on either the old or new state, so it doesn't really make much sense to convert them. The encoders' atomic_check and atomic_mode_set operate on the CRTC and connector state connected to them since encoders don't have a state of their own. Without those state pointers, we would need to get the CRTC through the drm_connector_state crtc pointer. However, in order to get the drm_connector_state pointer, we would need to get the connector itself and while usually we have a single connector connected to the encoder, we can't really get it from the encoder at the moment since it could be behind any number of bridges. While this could be addressed by (for example) listing all the connectors and finding the one that has the encoder as its source, it feels like an unnecessary rework for something that is slowly getting replaced by bridges. Since all the users that matter have been converted, let's remove the TODO item. Acked-by: Daniel Vetter Signed-off-by: Maxime Ripard Acked-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20210219120032.260676-11-maxime@cerno.tech --- Documentation/gpu/todo.rst | 46 ---------------------------------------------- 1 file changed, 46 deletions(-) (limited to 'Documentation') diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index f872d3d33218..0631b9b323d5 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -459,52 +459,6 @@ Contact: Emil Velikov, respective driver maintainers Level: Intermediate -Plumb drm_atomic_state all over -------------------------------- - -Currently various atomic functions take just a single or a handful of -object states (eg. plane state). While that single object state can -suffice for some simple cases, we often have to dig out additional -object states for dealing with various dependencies between the individual -objects or the hardware they represent. The process of digging out the -additional states is rather non-intuitive and error prone. - -To fix that most functions should rather take the overall -drm_atomic_state as one of their parameters. The other parameters -would generally be the object(s) we mainly want to interact with. - -For example, instead of - -.. code-block:: c - - int (*atomic_check)(struct drm_plane *plane, struct drm_plane_state *state); - -we would have something like - -.. code-block:: c - - int (*atomic_check)(struct drm_plane *plane, struct drm_atomic_state *state); - -The implementation can then trivially gain access to any required object -state(s) via drm_atomic_get_plane_state(), drm_atomic_get_new_plane_state(), -drm_atomic_get_old_plane_state(), and their equivalents for -other object types. - -Additionally many drivers currently access the object->state pointer -directly in their commit functions. That is not going to work if we -eg. want to allow deeper commit pipelines as those pointers could -then point to the states corresponding to a future commit instead of -the current commit we're trying to process. Also non-blocking commits -execute locklessly so there are serious concerns with dereferencing -the object->state pointers without holding the locks that protect them. -Use of drm_atomic_get_new_plane_state(), drm_atomic_get_old_plane_state(), -etc. avoids these problems as well since they relate to a specific -commit via the passed in drm_atomic_state. - -Contact: Ville Syrjälä, Daniel Vetter - -Level: Intermediate - Use struct dma_buf_map throughout codebase ------------------------------------------ -- cgit