* Re: [PATCH] coresight: drop lookup reference in coresight_get_sink_by_id()
From: Suzuki K Poulose @ 2026-05-19 9:06 UTC (permalink / raw)
To: Ma Ke, mike.leach, james.clark, leo.yan, alexander.shishkin,
mathieu.poirier, peterz, acme
Cc: coresight, linux-arm-kernel, linux-kernel, akpm, stable
In-Reply-To: <20260519084317.1472444-1-make24@iscas.ac.cn>
On 19/05/2026 09:43, Ma Ke wrote:
> bus_find_device() returns a device with its reference count
> incremented. coresight_get_sink_by_id() only uses the returned device
> to find the matching CoreSight sink by id and does not need to
> transfer this lookup reference to its callers.
>
> Keeping the reference forces callers such as etm_setup_aux() to know
> about the internal lookup implementation and to drop the reference
> themselves. This is error-prone and led to a leaked reference when a
> user-selected sink is used for perf AUX tracing.
>
> Drop the reference inside coresight_get_sink_by_id() after converting
> the device to the corresponding coresight_device. The CoreSight path
> code takes device references it needs when building/using the path.
>
> Found by code review.
Thanks for the report. But..
>
> Signed-off-by: Ma Ke <make24@iscas.ac.cn>
> Cc: stable@vger.kernel.org
> Fixes: 226443925887 ("coresight: Use event attributes for sink selection")
I would rather drop the reference in the etm_setup_aux, to make sure we
are still dealing with a valid device, that has not been removed under
our feet.
Suzuki
> ---
> drivers/hwtracing/coresight/coresight-core.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 46f247f73cf6..2cca4ed83e2c 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -624,11 +624,24 @@ static int coresight_sink_by_id(struct device *dev, const void *data)
> struct coresight_device *coresight_get_sink_by_id(u32 id)
> {
> struct device *dev = NULL;
> + struct coresight_device *csdev;
>
> dev = bus_find_device(&coresight_bustype, NULL, &id,
> coresight_sink_by_id);
> + if (!dev)
> + return NULL;
> +
> + csdev = to_coresight_device(dev);
> +
> + /*
> + * bus_find_device() returns a device with its reference count
> + * incremented. coresight_get_sink_by_id() only performs a lookup;
> + * the CoreSight path code takes the references it needs when the
> + * path is built, so drop the lookup reference here.
> + */
> + put_device(dev);
>
> - return dev ? to_coresight_device(dev) : NULL;
> + return csdev;
> }
>
> /**
^ permalink raw reply
* Re: [PATCH 1/8] mm: Add ptep_try_install() for lockless empty-slot installs
From: David Hildenbrand (Arm) @ 2026-05-19 9:05 UTC (permalink / raw)
To: Tejun Heo
Cc: David Vernet, Andrea Righi, Changwoo Min, Alexei Starovoitov,
Andrii Nakryiko, Daniel Borkmann, Martin KaFai Lau,
Kumar Kartikeya Dwivedi, Catalin Marinas, Will Deacon,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
Andrew Morton, Mike Rapoport, Emil Tsalapatis, sched-ext, bpf,
x86, linux-arm-kernel, linux-mm, linux-kernel
In-Reply-To: <297658c4ae2d6e7103f5968efc936224@kernel.org>
On 5/19/26 10:58, Tejun Heo wrote:
> Hello, David.
>
> On Tue, May 19, 2026 at 10:00:39AM +0200, David Hildenbrand (Arm) wrote:
>> Is that really possible? I'd much rather prefer to trylock and retry, unless
>> that can really result in deadlocks. But I have the feeling that such deadlocks
>> should be impossible here.
>
> I'm not well versed in either mm or BPF, so the BPF folks will have a
> better take. But here's a scenario that seemed plausible to me:
>
> 1. A bpf prog calls bpf_arena_alloc_pages() on its arena. The kernel
> takes arena->spinlock via raw_res_spin_lock_irqsave().
> 2. Under the lock, the alloc path goes through bpf_map_alloc_pages()
> -> alloc_pages_node(), which fires trace_mm_page_alloc().
> 3. A BPF tracepoint program on mm_page_alloc that shares the arena
> starts running with the lock still held.
> 4. The tracepoint program calls a kfunc, passing an arena pointer
> one entry past the array it meant to touch.
> 5. The kfunc dereferences. The kernel-side address is unbacked, so
> the CPU faults.
>
> trylock + retry at 5 would A-A deadlock.
Okay, so removing that specific tracepoint (or rather, any tracpoints under the
lock) would solve the problem, right?
>
>> For example, staring at apply_range_set_cb(), what prevents:
>>
>> (1) apply_range_set_cb() finding pte_none(ptep_get(pte)
>> (2) apply_range_set_scratch_cb() succeeding ptep_try_install()
>> (3) apply_range_set_cb() overwriting the pte with set_pte_at()
>>
>> Between (2) and (3) CPUs could access the scratch PTE.
>
> Scratch only gets installed when BPF passes an unallocated arena
> address to the kernel side, which is itself the violation, reported
> through the program's BPF stream. Behavior at that addr is then
> undefined. For scx, the scheduler should be aborted and torn down.
>
> The only requirements are that the kernel doesn't oops and the
> violation gets caught. Beyond that, behavior at the address is
> unspecified, and which installer wins the race doesn't matter as
> long as kernel integrity holds.
You'll have inconsistent TLB state.
I really don't like that approach.
We should really try to just take the lock, and remove any code under the lock
that could trigger such unpleasant deadlocks.
Is that feasible?
--
Cheers,
David
^ permalink raw reply
* Re: [PATCH] firmware: arm_scmi: Fix OOB in scmi_power_name_get()
From: Cristian Marussi @ 2026-05-19 9:05 UTC (permalink / raw)
To: Dan Carpenter
Cc: Cristian Marussi, Geert Uytterhoeven, Sudeep Holla, arm-scmi,
linux-arm-kernel, linux-kernel
In-Reply-To: <agwjfyMykDJTlrBd@stanley.mountain>
On Tue, May 19, 2026 at 11:46:55AM +0300, Dan Carpenter wrote:
> On Tue, May 19, 2026 at 09:36:40AM +0100, Cristian Marussi wrote:
> > On Fri, May 15, 2026 at 01:10:56PM +0100, Cristian Marussi wrote:
> > > On Fri, May 15, 2026 at 02:00:24PM +0200, Geert Uytterhoeven wrote:
> > > > Hi Cristian,
> > > >
> > > > On Fri, 15 May 2026 at 13:46, Cristian Marussi <cristian.marussi@arm.com> wrote:
> > > > > On Fri, May 15, 2026 at 01:29:27PM +0200, Geert Uytterhoeven wrote:
> > > > > > On Fri, 15 May 2026 at 12:28, Dan Carpenter <error27@gmail.com> wrote:
> > > > > > > On Fri, May 15, 2026 at 11:59:15AM +0200, Geert Uytterhoeven wrote:
> > > > > > > > scmi_power_name_get() does not validate the domain number passed by the
> > > > > > > > external caller, which may lead to an out-of-bounds access.
> > > > > > >
> > > > > > > Is an external caller an out of tree caller? So far as I can see this
> > > > > >
> > > > > > I meant a caller outside drivers/firmware/arm_scmi/.
> > > > > >
> > > > > > > is only called by scmi_pm_domain_probe().
> > > > > > >
> > > > > > > scmi_pd->name = power_ops->name_get(ph, i);
> > > > > > >
> > > > > > > where i < num_domains.
> > > > > >
> > > > > > You are right. But this seems to be only API implementation in
> > > > > > drivers/firmware/arm_scmi/ that does not validate the passed domain
> > > > > > number.
> > > > >
> > > > > Yes we tend to validate protocol operations calls even if apparently
> > > > > safe from teh caller perspective...indeed I have this fixed locally
> > > > > since ages in an horrible patch, that does a lot more, and that I
> > > > > never posted :P
> > > > >
> > > > > Usually, if it is worth, we also build an internal domain get helper to
> > > > > reuse across the protocol unit...but here really there are only 2 call-sites.
> > > > >
> > > > > What I am not sure is what to return: "unknown" is safer as of now than NULL
> > > > > for sure, but really, what happened is NOT that the name was "unknown" (which
> > > > > by itself would be out-of-spec behaviour) it is more that the whole domain that
> > > > > was referred to that was invalid and NOT existent...
> > > > >
> > > > > ....mmm I suppose we are opening another can of worms here :P
> > > >
> > > > Like scmi_perf_info_get() returning ERR_PTR(-EINVAL) instead of NULL,
> > > > and scmi_perf_domain_probe() never checking the return value anyway?
> > >
> > > ...oh probably more than that...and related vendor FW that already exploits
> > > these missing checks here and there to arbitrarily skip domains and return
> > > out-of-spec non-contigous sets of domains becasue they cannot bother to
> > > implement properly the spec (or they have simply forked their codebase from
> > > an old drop and never updated it again...)...so that any kernel-side fix
> > > you made along the road carries the risk of breaking something and a string
> > > of possibly needed quirks...
> >
> > Anyway, it is the safest option on the table until proper checks are in place.
> >
> > Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
>
> If it has a description like this then it's absolutely going to get a CVE
> assigned. We're used to hundreds of CVEs and all but I really feel like
> this is a bad habit.
Indeed, I think already happened to get a CVE on this internal improved
checks despite the fix was more a defensive thing since it had no chance
to be exposed by the current code.
I could be wrong but I think that this is one of the reason I started using
(and maybe abusing) for similar patches the "Harden protocol...." commmit-msg
because it really does not qualify as Fixes for backporting as specified in [1]
[1]: https://www.kernel.org/doc/Documentation/process/stable-kernel-rules.rst
...so at the end probably worth to drop Fixes as you said earlier...
Thanks,
Cristian
^ permalink raw reply
* Re: [PATCH 0/3] iommu/io-pgtable-arm: iommu-pages and cleanup
From: Jörg Rödel @ 2026-05-19 9:04 UTC (permalink / raw)
To: Mostafa Saleh
Cc: iommu, linux-arm-kernel, linux-kernel, robin.murphy, will, jgg
In-Reply-To: <20260513215203.3852661-1-smostafa@google.com>
On Wed, May 13, 2026 at 09:52:00PM +0000, Mostafa Saleh wrote:
> Mostafa Saleh (3):
> iommu/io-pgtable-arm: Use consistent sizes for page allocation and
> freeing
> iommu/io-pgtable-arm: Rework to use the iommu-pages API
> iommu/io-pgtable-arm: Use address conversion consistently
>
> drivers/iommu/io-pgtable-arm.c | 88 +++++++++++++++++++++++-----------
> 1 file changed, 61 insertions(+), 27 deletions(-)
Applied, thanks.
^ permalink raw reply
* Re: [PATCH v4 09/10] dt-bindings: firmware: add arm,ras-cper
From: Ahmed Tiba @ 2026-05-19 9:02 UTC (permalink / raw)
To: Krzysztof Kozlowski, rafael, bp, saket.dumbre, will, xueshuai,
mchehab, krzk+dt, dave, conor+dt, vishal.l.verma, jic23, corbet,
guohanjun, dave.jiang, catalin.marinas, lenb, tony.luck, skhan,
djbw, alison.schofield, ira.weiny, robh
Cc: devicetree, linux-acpi, linux-doc, Dmitry.Lamerov, linux-cxl,
Michael.Zhao2, acpica-devel, linux-kernel, linux-arm-kernel,
linux-edac
In-Reply-To: <5fb43b8d-e772-42af-ba78-d75abd87bd0c@kernel.org>
On 19/05/2026 08:04, Krzysztof Kozlowski wrote:
> On 18/05/2026 13:57, Ahmed Tiba wrote:
>> Describe the DeviceTree node that exposes the Arm firmware-first
>> CPER provider and hook the file into MAINTAINERS so the
>> binding has an owner.
>>
>> Signed-off-by: Ahmed Tiba <ahmed.tiba@arm.com>
>
> Please implement previous comments.
Could you please clarify which previous DT comments you still see
as unaddressed?
My understanding was that I had addressed the earlier points on the YAML
description formatting, the `memory-region` description text, and the
example. If I missed a specific item beyond the one below, please point
me to it.
>
>> ---
>> .../devicetree/bindings/firmware/arm,ras-cper.yaml | 71 ++++++++++++++++++++++
>> MAINTAINERS | 5 ++
>> 2 files changed, 76 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml b/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
>> new file mode 100644
>> index 000000000000..81dc37390af5
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/firmware/arm,ras-cper.yaml
>> @@ -0,0 +1,71 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/firmware/arm,ras-cper.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Arm RAS CPER provider
>> +
>> +maintainers:
>> + - Ahmed Tiba <ahmed.tiba@arm.com>
>> +
>> +description:
>> + Arm Reliability, Availability and Serviceability (RAS) firmware can expose
>> + a firmware-first CPER error source directly via DeviceTree. Firmware
>> + provides the CPER Generic Error Status block and notifies the OS through
>> + an interrupt.
>> +
>> +properties:
>> + compatible:
>> + const: arm,ras-cper
>> +
>> + memory-region:
>> + oneOf:
>> + - items:
>> + - description:
>> + CPER Generic Error Status block exposed by firmware
>> + - items:
>> + - description:
>> + CPER Generic Error Status block exposed by firmware.
>
> Also, this is just a list with minItems. No need for oneOf.
>
Understood, I will drop the oneOf and use a plain list with minItems
Best regards,
Ahmed
^ permalink raw reply
* [PATCH v5 19/19] drm/bridge_connector: Convert to atomic_create_state
From: Maxime Ripard @ 2026-05-19 9:02 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
The connector created by drm_bridge_connector only initializes a
pristine state in reset, which is equivalent to what
atomic_create_state would expect. Convert to it.
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/display/drm_bridge_connector.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
index 50408af746d8..cafa498c3848 100644
--- a/drivers/gpu/drm/display/drm_bridge_connector.c
+++ b/drivers/gpu/drm/display/drm_bridge_connector.c
@@ -263,26 +263,33 @@ static void drm_bridge_connector_debugfs_init(struct drm_connector *connector,
if (bridge->funcs->debugfs_init)
bridge->funcs->debugfs_init(bridge, root);
}
}
-static void drm_bridge_connector_reset(struct drm_connector *connector)
+static struct drm_connector_state *
+drm_bridge_connector_create_state(struct drm_connector *connector)
{
struct drm_bridge_connector *bridge_connector =
to_drm_bridge_connector(connector);
+ struct drm_connector_state *conn_state;
+
+ conn_state = drm_atomic_helper_connector_create_state(connector);
+ if (IS_ERR(conn_state))
+ return conn_state;
- drm_atomic_helper_connector_reset(connector);
if (bridge_connector->bridge_hdmi)
__drm_atomic_helper_connector_hdmi_state_init(connector,
- connector->state);
+ conn_state);
+
+ return conn_state;
}
static const struct drm_connector_funcs drm_bridge_connector_funcs = {
- .reset = drm_bridge_connector_reset,
.detect = drm_bridge_connector_detect,
.force = drm_bridge_connector_force,
.fill_modes = drm_helper_probe_single_connector_modes,
+ .atomic_create_state = drm_bridge_connector_create_state,
.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
.debugfs_init = drm_bridge_connector_debugfs_init,
.oob_hotplug_event = drm_bridge_connector_oob_hotplug_event,
};
--
2.54.0
^ permalink raw reply related
* [PATCH v5 15/19] drm/connector: Add new atomic_create_state callback
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
Commit 47b5ac7daa46 ("drm/atomic: Add new atomic_create_state callback
to drm_private_obj") introduced a new pattern for allocating drm object
states.
Instead of relying on the reset() callback, it created a new
atomic_create_state hook. This is helpful because reset is a bit
overloaded: it's used to create the initial software state, reset it,
but also reset the hardware.
It can also be used either at probe time, to create the initial state
and possibly reset the hardware to an expected default, but also during
suspend/resume.
Both these cases come with different expectations too: during the
initialization, we want to initialize all states, but during
suspend/resume, drm_private_states for example are expected to be kept
around.
reset() also isn't fallible, which makes it harder to handle
initialization errors properly. This is only really relevant for some
drivers though, since all the helpers for reset only create a new
state, and don't touch the hardware at all.
It was thus decided to create a new hook that would allocate and
initialize a pristine state without any side effect:
atomic_create_state to untangle a bit some of it, and to separate the
initialization with the actual reset one might need during a
suspend/resume.
Continue the transition to the new pattern with connectors.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_atomic_state_helper.c | 26 ++++++++++++++++++++++++++
drivers/gpu/drm/drm_connector.c | 10 +++++++++-
drivers/gpu/drm/drm_mode_config.c | 31 ++++++++++++++++++++++++++++++-
include/drm/drm_atomic_state_helper.h | 2 ++
include/drm/drm_connector.h | 16 ++++++++++++++++
5 files changed, 83 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index e2e5a1b8a820..07686e94aae0 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -532,10 +532,36 @@ void drm_atomic_helper_connector_reset(struct drm_connector *connector)
kfree(connector->state);
__drm_atomic_helper_connector_reset(connector, conn_state);
}
EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
+/**
+ * drm_atomic_helper_connector_create_state - default &drm_connector_funcs.atomic_create_state hook for connectors
+ * @connector: connector object
+ *
+ * Allocates and initializes pristine @drm_connector_state.
+ *
+ * This is useful for drivers that don't subclass @drm_connector_state.
+ *
+ * RETURNS:
+ * Pointer to new connector state, or ERR_PTR on failure.
+ */
+struct drm_connector_state *
+drm_atomic_helper_connector_create_state(struct drm_connector *connector)
+{
+ struct drm_connector_state *state;
+
+ state = kzalloc_obj(*state);
+ if (!state)
+ return ERR_PTR(-ENOMEM);
+
+ __drm_atomic_helper_connector_state_init(state, connector);
+
+ return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_create_state);
+
/**
* drm_atomic_helper_connector_tv_margins_reset - Resets TV connector properties
* @connector: DRM connector
*
* Resets the TV-related properties attached to a connector.
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 3fa4d2082cd7..a0b132c658a1 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -616,11 +616,19 @@ int drmm_connector_hdmi_init(struct drm_device *dev,
/*
* drm_connector_attach_max_bpc_property() requires the
* connector to have a state.
*/
- if (connector->funcs->reset)
+ if (connector->funcs->atomic_create_state) {
+ struct drm_connector_state *state;
+
+ state = connector->funcs->atomic_create_state(connector);
+ if (IS_ERR(state))
+ return PTR_ERR(state);
+
+ connector->state = state;
+ } else if (connector->funcs->reset)
connector->funcs->reset(connector);
drm_connector_attach_max_bpc_property(connector, 8, max_bpc);
connector->max_bpc = max_bpc;
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index 2e2cd18a14b4..9d240817f8b6 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -235,10 +235,36 @@ static int drm_mode_config_crtc_reset_with_create_state(struct drm_crtc *crtc)
}
return drm_mode_config_crtc_create_state(crtc);
}
+static int drm_mode_config_connector_create_state(struct drm_connector *connector)
+{
+ struct drm_connector_state *conn_state;
+
+ if (!connector->funcs->atomic_create_state)
+ return 0;
+
+ conn_state = connector->funcs->atomic_create_state(connector);
+ if (IS_ERR(conn_state))
+ return PTR_ERR(conn_state);
+
+ connector->state = conn_state;
+
+ return 0;
+}
+
+static int drm_mode_config_connector_reset_with_create_state(struct drm_connector *connector)
+{
+ if (connector->state) {
+ connector->funcs->atomic_destroy_state(connector, connector->state);
+ connector->state = NULL;
+ }
+
+ return drm_mode_config_connector_create_state(connector);
+}
+
/**
* drm_mode_config_reset - call ->reset callbacks
* @dev: drm device
*
* This functions calls all the crtc's, encoder's and connector's ->reset
@@ -278,13 +304,16 @@ void drm_mode_config_reset(struct drm_device *dev)
drm_for_each_encoder(encoder, dev)
if (encoder->funcs && encoder->funcs->reset)
encoder->funcs->reset(encoder);
drm_connector_list_iter_begin(dev, &conn_iter);
- drm_for_each_connector_iter(connector, &conn_iter)
+ drm_for_each_connector_iter(connector, &conn_iter) {
if (connector->funcs->reset)
connector->funcs->reset(connector);
+ else if (connector->funcs->atomic_create_state)
+ drm_mode_config_connector_reset_with_create_state(connector);
+ }
drm_connector_list_iter_end(&conn_iter);
}
EXPORT_SYMBOL(drm_mode_config_reset);
/*
diff --git a/include/drm/drm_atomic_state_helper.h b/include/drm/drm_atomic_state_helper.h
index 9634a70e0401..f4b6d8833bc2 100644
--- a/include/drm/drm_atomic_state_helper.h
+++ b/include/drm/drm_atomic_state_helper.h
@@ -73,10 +73,12 @@ void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
void __drm_atomic_helper_connector_state_init(struct drm_connector_state *conn_state,
struct drm_connector *connector);
void __drm_atomic_helper_connector_reset(struct drm_connector *connector,
struct drm_connector_state *conn_state);
void drm_atomic_helper_connector_reset(struct drm_connector *connector);
+struct drm_connector_state *
+drm_atomic_helper_connector_create_state(struct drm_connector *connector);
void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector);
int drm_atomic_helper_connector_tv_check(struct drm_connector *connector,
struct drm_atomic_commit *state);
void drm_atomic_helper_connector_tv_margins_reset(struct drm_connector *connector);
void
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 5ad62c207d00..529755c2e862 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1569,10 +1569,26 @@ struct drm_connector_funcs {
* when a connector is being hot-unplugged for drivers that support
* connector hotplugging (e.g. DisplayPort MST).
*/
void (*destroy)(struct drm_connector *connector);
+ /**
+ * @atomic_create_state:
+ *
+ * Allocate a pristine, initialized, state for the connector
+ * object and return it. This callback must have no side
+ * effects: in particular, the returned state must not be
+ * assigned to the object's state pointer and it must not affect
+ * the hardware state.
+ *
+ * RETURNS:
+ *
+ * A new, pristine, connector state instance or an error pointer
+ * on failure.
+ */
+ struct drm_connector_state *(*atomic_create_state)(struct drm_connector *connector);
+
/**
* @atomic_duplicate_state:
*
* Duplicate the current atomic state for this connector and return it.
* The core and helpers guarantee that any atomic state duplicated with
--
2.54.0
^ permalink raw reply related
* [PATCH v5 18/19] drm/tidss: Convert to atomic_create_state
From: Maxime Ripard @ 2026-05-19 9:02 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
Our driver uses reset to create the various object states, but only
calls the helper that allocate a new state. They are thus strictly
equivalent to the new atomic_create_state helpers, so let's switch to
these.
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/tidss/tidss_crtc.c | 17 +++++++----------
drivers/gpu/drm/tidss/tidss_plane.c | 2 +-
2 files changed, 8 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/tidss/tidss_crtc.c b/drivers/gpu/drm/tidss/tidss_crtc.c
index acab9307bdf3..400329aa2200 100644
--- a/drivers/gpu/drm/tidss/tidss_crtc.c
+++ b/drivers/gpu/drm/tidss/tidss_crtc.c
@@ -355,24 +355,21 @@ static void tidss_crtc_destroy_state(struct drm_crtc *crtc,
__drm_atomic_helper_crtc_destroy_state(&tstate->base);
kfree(tstate);
}
-static void tidss_crtc_reset(struct drm_crtc *crtc)
+static struct drm_crtc_state *tidss_crtc_create_state(struct drm_crtc *crtc)
{
struct tidss_crtc_state *tstate;
- if (crtc->state)
- tidss_crtc_destroy_state(crtc, crtc->state);
-
tstate = kzalloc_obj(*tstate);
- if (!tstate) {
- crtc->state = NULL;
- return;
- }
+ if (!tstate)
+ return ERR_PTR(-ENOMEM);
- __drm_atomic_helper_crtc_reset(crtc, &tstate->base);
+ __drm_atomic_helper_crtc_state_init(&tstate->base, crtc);
+
+ return &tstate->base;
}
static struct drm_crtc_state *tidss_crtc_duplicate_state(struct drm_crtc *crtc)
{
struct tidss_crtc_state *state, *current_state;
@@ -403,14 +400,14 @@ static void tidss_crtc_destroy(struct drm_crtc *crtc)
drm_crtc_cleanup(crtc);
kfree(tcrtc);
}
static const struct drm_crtc_funcs tidss_crtc_funcs = {
- .reset = tidss_crtc_reset,
.destroy = tidss_crtc_destroy,
.set_config = drm_atomic_helper_set_config,
.page_flip = drm_atomic_helper_page_flip,
+ .atomic_create_state = tidss_crtc_create_state,
.atomic_duplicate_state = tidss_crtc_duplicate_state,
.atomic_destroy_state = tidss_crtc_destroy_state,
.enable_vblank = tidss_crtc_enable_vblank,
.disable_vblank = tidss_crtc_disable_vblank,
};
diff --git a/drivers/gpu/drm/tidss/tidss_plane.c b/drivers/gpu/drm/tidss/tidss_plane.c
index 1a8b44fb45f8..6d82976c2db1 100644
--- a/drivers/gpu/drm/tidss/tidss_plane.c
+++ b/drivers/gpu/drm/tidss/tidss_plane.c
@@ -176,12 +176,12 @@ static const struct drm_plane_helper_funcs tidss_primary_plane_helper_funcs = {
};
static const struct drm_plane_funcs tidss_plane_funcs = {
.update_plane = drm_atomic_helper_update_plane,
.disable_plane = drm_atomic_helper_disable_plane,
- .reset = drm_atomic_helper_plane_reset,
.destroy = drm_plane_destroy,
+ .atomic_create_state = drm_atomic_helper_plane_create_state,
.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
};
struct tidss_plane *tidss_plane_create(struct tidss_device *tidss,
--
2.54.0
^ permalink raw reply related
* [PATCH v5 17/19] drm/drv: Switch skeleton to drm_mode_config_create_initial_state()
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
The driver skeleton currently recommends calling
drm_mode_config_reset() at probe time to create the initial state.
Now that drm_mode_config_create_initial_state() exists to handle
initial state allocation without hardware side effects, update the
skeleton to recommend it instead.
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_drv.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 985c283cf59f..f537556b06a8 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -340,11 +340,13 @@ void drm_minor_release(struct drm_minor *minor)
*
* // Further setup, display pipeline etc
*
* platform_set_drvdata(pdev, drm);
*
- * drm_mode_config_reset(drm);
+ * ret = drm_mode_config_create_initial_state(drm);
+ * if (ret)
+ * return ret;
*
* ret = drm_dev_register(drm);
* if (ret)
* return ret;
*
--
2.54.0
^ permalink raw reply related
* [PATCH v5 12/19] drm/crtc: Add new atomic_create_state callback
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
Commit 47b5ac7daa46 ("drm/atomic: Add new atomic_create_state callback
to drm_private_obj") introduced a new pattern for allocating drm object
states.
Instead of relying on the reset() callback, it created a new
atomic_create_state hook. This is helpful because reset is a bit
overloaded: it's used to create the initial software state, reset it,
but also reset the hardware.
It can also be used either at probe time, to create the initial state
and possibly reset the hardware to an expected default, but also during
suspend/resume.
Both these cases come with different expectations too: during the
initialization, we want to initialize all states, but during
suspend/resume, drm_private_states for example are expected to be kept
around.
reset() also isn't fallible, which makes it harder to handle
initialization errors properly. This is only really relevant for some
drivers though, since all the helpers for reset only create a new
state, and don't touch the hardware at all.
It was thus decided to create a new hook that would allocate and
initialize a pristine state without any side effect:
atomic_create_state to untangle a bit some of it, and to separate the
initialization with the actual reset one might need during a
suspend/resume.
Continue the transition to the new pattern with CRTCs.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_atomic_state_helper.c | 25 +++++++++++++++++++++++
drivers/gpu/drm/drm_mode_config.c | 34 ++++++++++++++++++++++++++++++-
include/drm/drm_atomic_state_helper.h | 2 ++
include/drm/drm_crtc.h | 16 +++++++++++++++
4 files changed, 76 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index b277f92f4532..8762171c9432 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -122,10 +122,35 @@ void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
__drm_atomic_helper_crtc_reset(crtc, crtc_state);
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);
+/**
+ * drm_atomic_helper_crtc_create_state - default &drm_crtc_funcs.atomic_create_state hook for crtcs
+ * @crtc: crtc object
+ *
+ * Allocates and initializes pristine @drm_crtc_state.
+ *
+ * This is useful for drivers that don't subclass @drm_crtc_state.
+ *
+ * RETURNS:
+ * Pointer to new crtc state, or ERR_PTR on failure.
+ */
+struct drm_crtc_state *drm_atomic_helper_crtc_create_state(struct drm_crtc *crtc)
+{
+ struct drm_crtc_state *state;
+
+ state = kzalloc_obj(*state);
+ if (!state)
+ return ERR_PTR(-ENOMEM);
+
+ __drm_atomic_helper_crtc_state_init(state, crtc);
+
+ return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_create_state);
+
/**
* __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
* @crtc: CRTC object
* @state: atomic CRTC state
*
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index fa609357858f..2e2cd18a14b4 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -206,10 +206,39 @@ static int drm_mode_config_plane_reset_with_create_state(struct drm_plane *plane
}
return drm_mode_config_plane_create_state(plane);
}
+static int drm_mode_config_crtc_create_state(struct drm_crtc *crtc)
+{
+ struct drm_crtc_state *crtc_state;
+
+ if (!crtc->funcs->atomic_create_state)
+ return 0;
+
+ crtc_state = crtc->funcs->atomic_create_state(crtc);
+ if (IS_ERR(crtc_state))
+ return PTR_ERR(crtc_state);
+
+ if (drm_dev_has_vblank(crtc->dev))
+ drm_crtc_vblank_reset(crtc);
+
+ crtc->state = crtc_state;
+
+ return 0;
+}
+
+static int drm_mode_config_crtc_reset_with_create_state(struct drm_crtc *crtc)
+{
+ if (crtc->state) {
+ crtc->funcs->atomic_destroy_state(crtc, crtc->state);
+ crtc->state = NULL;
+ }
+
+ return drm_mode_config_crtc_create_state(crtc);
+}
+
/**
* drm_mode_config_reset - call ->reset callbacks
* @dev: drm device
*
* This functions calls all the crtc's, encoder's and connector's ->reset
@@ -237,13 +266,16 @@ void drm_mode_config_reset(struct drm_device *dev)
plane->funcs->reset(plane);
else if (plane->funcs->atomic_create_state)
drm_mode_config_plane_reset_with_create_state(plane);
}
- drm_for_each_crtc(crtc, dev)
+ drm_for_each_crtc(crtc, dev) {
if (crtc->funcs->reset)
crtc->funcs->reset(crtc);
+ else if (crtc->funcs->atomic_create_state)
+ drm_mode_config_crtc_reset_with_create_state(crtc);
+ }
drm_for_each_encoder(encoder, dev)
if (encoder->funcs && encoder->funcs->reset)
encoder->funcs->reset(encoder);
diff --git a/include/drm/drm_atomic_state_helper.h b/include/drm/drm_atomic_state_helper.h
index 0bb72453464a..213f7e298008 100644
--- a/include/drm/drm_atomic_state_helper.h
+++ b/include/drm/drm_atomic_state_helper.h
@@ -43,10 +43,12 @@ struct drm_device;
void __drm_atomic_helper_crtc_state_init(struct drm_crtc_state *state,
struct drm_crtc *crtc);
void __drm_atomic_helper_crtc_reset(struct drm_crtc *crtc,
struct drm_crtc_state *state);
void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc);
+struct drm_crtc_state *
+drm_atomic_helper_crtc_create_state(struct drm_crtc *crtc);
void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
struct drm_crtc_state *state);
struct drm_crtc_state *
drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc);
void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index c6dbe8b7db9e..152349f973e3 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -636,10 +636,26 @@ struct drm_crtc_funcs {
* 0 on success or a negative error code on failure.
*/
int (*set_property)(struct drm_crtc *crtc,
struct drm_property *property, uint64_t val);
+ /**
+ * @atomic_create_state:
+ *
+ * Allocate a pristine, initialized, state for the CRTC object
+ * and return it. This callback must have no side effects: in
+ * particular, the returned state must not be assigned to the
+ * object's state pointer and it must not affect the hardware
+ * state.
+ *
+ * RETURNS:
+ *
+ * A new, pristine, CRTC state instance or an error pointer
+ * on failure.
+ */
+ struct drm_crtc_state *(*atomic_create_state)(struct drm_crtc *crtc);
+
/**
* @atomic_duplicate_state:
*
* Duplicate the current atomic state for this CRTC and return it.
* The core and helpers guarantee that any atomic state duplicated with
--
2.54.0
^ permalink raw reply related
* [PATCH v5 10/19] drm/plane: Add new atomic_create_state callback
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
Commit 47b5ac7daa46 ("drm/atomic: Add new atomic_create_state callback
to drm_private_obj") introduced a new pattern for allocating drm object
states.
Instead of relying on the reset() callback, it created a new
atomic_create_state hook. This is helpful because reset is a bit
overloaded: it's used to create the initial software state, reset it,
but also reset the hardware.
It can also be used either at probe time, to create the initial state
and possibly reset the hardware to an expected default, but also during
suspend/resume.
Both these cases come with different expectations too: during the
initialization, we want to initialize all states, but during
suspend/resume, drm_private_states for example are expected to be kept
around.
reset() also isn't fallible, which makes it harder to handle
initialization errors properly. This is only really relevant for some
drivers though, since all the helpers for reset only create a new
state, and don't touch the hardware at all.
It was thus decided to create a new hook that would allocate and
initialize a pristine state without any side effect:
atomic_create_state to untangle a bit some of it, and to separate the
initialization with the actual reset one might need during a
suspend/resume.
Continue the transition to the new pattern with planes.
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_atomic_state_helper.c | 25 +++++++++++++++++++++++++
drivers/gpu/drm/drm_mode_config.c | 31 ++++++++++++++++++++++++++++++-
include/drm/drm_atomic_state_helper.h | 2 ++
include/drm/drm_plane.h | 16 ++++++++++++++++
4 files changed, 73 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index ee01700d4ca7..ab171bfe6e86 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -338,10 +338,35 @@ void drm_atomic_helper_plane_reset(struct drm_plane *plane)
if (plane->state)
__drm_atomic_helper_plane_reset(plane, plane->state);
}
EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
+/**
+ * drm_atomic_helper_plane_create_state - default &drm_plane_funcs.atomic_create_state hook for planes
+ * @plane: plane object
+ *
+ * Allocates and initializes pristine @drm_plane_state.
+ *
+ * This is useful for drivers that don't subclass @drm_plane_state.
+ *
+ * RETURNS:
+ * Pointer to new plane state, or ERR_PTR on failure.
+ */
+struct drm_plane_state *drm_atomic_helper_plane_create_state(struct drm_plane *plane)
+{
+ struct drm_plane_state *state;
+
+ state = kzalloc_obj(*state);
+ if (!state)
+ return ERR_PTR(-ENOMEM);
+
+ __drm_atomic_helper_plane_state_init(state, plane);
+
+ return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_create_state);
+
/**
* __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
* @plane: plane object
* @state: atomic plane state
*
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index c33382a38191..fa609357858f 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -180,10 +180,36 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
drm_connector_list_iter_end(&conn_iter);
return ret;
}
+static int drm_mode_config_plane_create_state(struct drm_plane *plane)
+{
+ struct drm_plane_state *plane_state;
+
+ if (!plane->funcs->atomic_create_state)
+ return 0;
+
+ plane_state = plane->funcs->atomic_create_state(plane);
+ if (IS_ERR(plane_state))
+ return PTR_ERR(plane_state);
+
+ plane->state = plane_state;
+
+ return 0;
+}
+
+static int drm_mode_config_plane_reset_with_create_state(struct drm_plane *plane)
+{
+ if (plane->state) {
+ plane->funcs->atomic_destroy_state(plane, plane->state);
+ plane->state = NULL;
+ }
+
+ return drm_mode_config_plane_create_state(plane);
+}
+
/**
* drm_mode_config_reset - call ->reset callbacks
* @dev: drm device
*
* This functions calls all the crtc's, encoder's and connector's ->reset
@@ -204,13 +230,16 @@ void drm_mode_config_reset(struct drm_device *dev)
struct drm_connector_list_iter conn_iter;
drm_for_each_colorop(colorop, dev)
drm_colorop_reset(colorop);
- drm_for_each_plane(plane, dev)
+ drm_for_each_plane(plane, dev) {
if (plane->funcs->reset)
plane->funcs->reset(plane);
+ else if (plane->funcs->atomic_create_state)
+ drm_mode_config_plane_reset_with_create_state(plane);
+ }
drm_for_each_crtc(crtc, dev)
if (crtc->funcs->reset)
crtc->funcs->reset(crtc);
diff --git a/include/drm/drm_atomic_state_helper.h b/include/drm/drm_atomic_state_helper.h
index 691c1ccfa4e0..8d1ef268fdef 100644
--- a/include/drm/drm_atomic_state_helper.h
+++ b/include/drm/drm_atomic_state_helper.h
@@ -53,10 +53,12 @@ void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state);
void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
struct drm_crtc_state *state);
void __drm_atomic_helper_plane_state_init(struct drm_plane_state *state,
struct drm_plane *plane);
+struct drm_plane_state *
+drm_atomic_helper_plane_create_state(struct drm_plane *plane);
void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
struct drm_plane_state *state);
void drm_atomic_helper_plane_reset(struct drm_plane *plane);
void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
struct drm_plane_state *state);
diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
index 419c88c873a6..2c5a5a70a71b 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -386,10 +386,26 @@ struct drm_plane_funcs {
* 0 on success or a negative error code on failure.
*/
int (*set_property)(struct drm_plane *plane,
struct drm_property *property, uint64_t val);
+ /**
+ * @atomic_create_state:
+ *
+ * Allocate a pristine, initialized, state for the plane object
+ * and return it. This callback must have no side effects: in
+ * particular, the returned state must not be assigned to the
+ * object's state pointer and it must not affect the hardware
+ * state.
+ *
+ * RETURNS:
+ *
+ * A new, pristine, plane state instance or an error pointer
+ * on failure.
+ */
+ struct drm_plane_state *(*atomic_create_state)(struct drm_plane *plane);
+
/**
* @atomic_duplicate_state:
*
* Duplicate the current atomic state for this plane and return it.
* The core and helpers guarantee that any atomic state duplicated with
--
2.54.0
^ permalink raw reply related
* [PATCH 8/8] drm: atmel-hlcdc: add LVDS output mode support
From: Manikandan Muralidharan @ 2026-05-19 9:01 UTC (permalink / raw)
To: maarten.lankhorst, mripard, tzimmermann, airlied, simona,
nicolas.ferre, alexandre.belloni, claudiu.beznea, lee, dri-devel,
linux-arm-kernel, linux-kernel
Cc: manikandan.m
In-Reply-To: <20260519090135.1188405-1-manikandan.m@microchip.com>
Introduce atmel_xlcdc_connector_output_lvds() to map LVDS bus
formats to the appropriate output mode, and wire it into
atmel_hlcdc_connector_output_mode() for LVDS encoder types.
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
.../gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 44 +++++++++++++++++--
1 file changed, 41 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index 73a8650bc9b7..9f46c368835e 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -407,6 +407,42 @@ static int atmel_xlcdc_connector_output_dsi(struct drm_encoder *encoder,
return supported_fmts;
}
+static int atmel_xlcdc_connector_output_lvds(struct drm_encoder *encoder,
+ struct drm_display_info *info)
+{
+ int j;
+ unsigned int supported_fmts = 0;
+
+ switch (atmel_hlcdc_encoder_get_bus_fmt(encoder)) {
+ case 0:
+ break;
+ case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
+ case MEDIA_BUS_FMT_RGB666_1X18:
+ return ATMEL_HLCDC_RGB666_OUTPUT;
+ case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+ case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+ return ATMEL_HLCDC_RGB888_OUTPUT;
+ default:
+ return -EINVAL;
+ }
+
+ for (j = 0; j < info->num_bus_formats; j++) {
+ switch (info->bus_formats[j]) {
+ case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
+ case MEDIA_BUS_FMT_RGB666_1X18:
+ supported_fmts |= ATMEL_HLCDC_RGB666_OUTPUT;
+ break;
+ case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+ case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+ supported_fmts |= ATMEL_HLCDC_RGB888_OUTPUT;
+ break;
+ default:
+ break;
+ }
+ }
+ return supported_fmts;
+}
+
static int atmel_hlcdc_connector_output_mode(struct drm_connector_state *state)
{
struct drm_connector *connector = state->connector;
@@ -419,12 +455,14 @@ static int atmel_hlcdc_connector_output_mode(struct drm_connector_state *state)
if (!encoder)
encoder = connector->encoder;
/*
- * atmel-hlcdc to support DSI formats with DSI video pipeline
- * when DRM_MODE_ENCODER_DSI type is set by
- * connector driver component.
+ * Select the output format based on the encoder type.
+ * DSI and LVDS encoders have dedicated format handlers,
+ * while other encoder types fall through to the generic path
*/
if (encoder->encoder_type == DRM_MODE_ENCODER_DSI)
return atmel_xlcdc_connector_output_dsi(encoder, info);
+ if (encoder->encoder_type == DRM_MODE_ENCODER_LVDS)
+ return atmel_xlcdc_connector_output_lvds(encoder, info);
switch (atmel_hlcdc_encoder_get_bus_fmt(encoder)) {
case 0:
--
2.25.1
^ permalink raw reply related
* [PATCH 7/8] drm: atmel-hlcdc: add and configure LVDS PLL clock support
From: Manikandan Muralidharan @ 2026-05-19 9:01 UTC (permalink / raw)
To: maarten.lankhorst, mripard, tzimmermann, airlied, simona,
nicolas.ferre, alexandre.belloni, claudiu.beznea, lee, dri-devel,
linux-arm-kernel, linux-kernel
Cc: manikandan.m
In-Reply-To: <20260519090135.1188405-1-manikandan.m@microchip.com>
Set the LVDS PLL rate to 7x the pixel clock.
set ATMEL_XLCDC_CLKBYP for the LVDS path, leaving clock
lifecycle management to the atomic callbacks and fallback to
sys_clk for non-LVDS displays with proper error handling.
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
.../gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 45 +++++++++++++++++--
1 file changed, 42 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index f837684654ea..73a8650bc9b7 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -26,6 +26,8 @@
#include "atmel_hlcdc_dc.h"
+#define ATMEL_LVDS_PLL_MULT 7
+
/**
* struct atmel_hlcdc_crtc_state - Atmel HLCDC CRTC state structure
*
@@ -66,6 +68,14 @@ drm_crtc_to_atmel_hlcdc_crtc(struct drm_crtc *crtc)
return container_of(crtc, struct atmel_hlcdc_crtc, base);
}
+static void atmel_hlcdc_crtc_disable_clock(struct atmel_hlcdc_crtc *crtc)
+{
+ if (crtc->dc->hlcdc->lvds_pll_clk)
+ clk_disable_unprepare(crtc->dc->hlcdc->lvds_pll_clk);
+ else
+ clk_disable_unprepare(crtc->dc->hlcdc->sys_clk);
+}
+
static int atmel_hlcdc_crtc_setup_clock(struct atmel_hlcdc_crtc *crtc,
unsigned long mode_rate,
unsigned int *cfg,
@@ -74,6 +84,12 @@ static int atmel_hlcdc_crtc_setup_clock(struct atmel_hlcdc_crtc *crtc,
unsigned long prate;
int div, ret;
+ if (crtc->dc->hlcdc->lvds_pll_clk) {
+ *cfg |= ATMEL_XLCDC_CLKBYP;
+ *mask |= ATMEL_XLCDC_CLKBYP;
+ return clk_prepare_enable(crtc->dc->hlcdc->lvds_pll_clk);
+ }
+
ret = clk_prepare_enable(crtc->dc->hlcdc->sys_clk);
if (ret)
return ret;
@@ -198,7 +214,7 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
ATMEL_XLCDC_DPI : ATMEL_HLCDC_MODE_MASK),
cfg);
- clk_disable_unprepare(crtc->dc->hlcdc->sys_clk);
+ atmel_hlcdc_crtc_disable_clock(crtc);
}
static enum drm_mode_status
@@ -254,7 +270,8 @@ static void atmel_hlcdc_crtc_atomic_disable(struct drm_crtc *c,
10, 1000))
drm_warn(dev, "Atmel LCDC status register CLKSTS timeout\n");
- clk_disable_unprepare(crtc->dc->hlcdc->sys_clk);
+ atmel_hlcdc_crtc_disable_clock(crtc);
+
pinctrl_pm_select_sleep_state(dev->dev);
pm_runtime_allow(dev->dev);
@@ -267,15 +284,33 @@ static void atmel_hlcdc_crtc_atomic_enable(struct drm_crtc *c,
{
struct drm_device *dev = c->dev;
struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
+ struct drm_display_mode *adj = &c->state->adjusted_mode;
struct regmap *regmap = crtc->dc->hlcdc->regmap;
unsigned int status;
+ int ret;
pm_runtime_get_sync(dev->dev);
pm_runtime_forbid(dev->dev);
pinctrl_pm_select_default_state(dev->dev);
- clk_prepare_enable(crtc->dc->hlcdc->sys_clk);
+
+ /*
+ * Set LVDS PLL clock rate (7x pixel clock) if available
+ */
+ if (crtc->dc->hlcdc->lvds_pll_clk) {
+ ret = clk_set_rate(crtc->dc->hlcdc->lvds_pll_clk,
+ adj->clock * 1000 * ATMEL_LVDS_PLL_MULT);
+ if (ret) {
+ drm_err(dev, "Failed to set LVDS PLL clk rate: %d\n", ret);
+ goto err_clk;
+ }
+ ret = clk_prepare_enable(crtc->dc->hlcdc->lvds_pll_clk);
+ } else {
+ ret = clk_prepare_enable(crtc->dc->hlcdc->sys_clk);
+ }
+ if (ret)
+ goto err_clk;
regmap_write(regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_PIXEL_CLK);
if (regmap_read_poll_timeout(regmap, ATMEL_HLCDC_SR, status,
@@ -310,7 +345,11 @@ static void atmel_hlcdc_crtc_atomic_enable(struct drm_crtc *c,
}
pm_runtime_put_sync(dev->dev);
+ return;
+err_clk:
+ pm_runtime_allow(dev->dev);
+ pm_runtime_put_sync(dev->dev);
}
#define ATMEL_HLCDC_RGB444_OUTPUT BIT(0)
--
2.25.1
^ permalink raw reply related
* [PATCH v5 09/19] drm/atomic-state-helper: Rename __drm_atomic_helper_plane_state_reset()
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart, Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
__drm_atomic_helper_plane_state_reset() is used to initialize a newly
allocated drm_plane_state, and is being typically called by the
drm_plane_funcs.reset implementation.
Since we want to consolidate DRM objects state allocation around the
atomic_create_state callback that will only allocate and initialize a
new drm_plane_state instance, we will need to call
__drm_atomic_helper_plane_state_reset() from both the reset and
atomic_create hooks.
To avoid any confusion, we can thus rename
__drm_atomic_helper_plane_state_reset() to
__drm_atomic_helper_plane_state_init().
Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_atomic_state_helper.c | 12 ++++++------
drivers/gpu/drm/i915/display/intel_plane.c | 2 +-
include/drm/drm_atomic_state_helper.h | 2 +-
3 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index c8ccf8be5074..ee01700d4ca7 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -235,19 +235,19 @@ void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);
/**
- * __drm_atomic_helper_plane_state_reset - resets plane state to default values
+ * __drm_atomic_helper_plane_state_init - Initialize the plane state
* @plane_state: atomic plane state, must not be NULL
* @plane: plane object, must not be NULL
*
* Initializes the newly allocated @plane_state with default
- * values. This is useful for drivers that subclass the CRTC state.
+ * values. This is useful for drivers that subclass the plane state.
*/
-void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
- struct drm_plane *plane)
+void __drm_atomic_helper_plane_state_init(struct drm_plane_state *plane_state,
+ struct drm_plane *plane)
{
u64 val;
plane_state->plane = plane;
plane_state->rotation = DRM_MODE_ROTATE_0;
@@ -295,11 +295,11 @@ void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
plane->hotspot_y_property,
&val))
plane_state->hotspot_y = val;
}
}
-EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);
+EXPORT_SYMBOL(__drm_atomic_helper_plane_state_init);
/**
* __drm_atomic_helper_plane_reset - reset state on plane
* @plane: drm plane
* @plane_state: plane state to assign
@@ -313,11 +313,11 @@ EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);
*/
void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
struct drm_plane_state *plane_state)
{
if (plane_state)
- __drm_atomic_helper_plane_state_reset(plane_state, plane);
+ __drm_atomic_helper_plane_state_init(plane_state, plane);
plane->state = plane_state;
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);
diff --git a/drivers/gpu/drm/i915/display/intel_plane.c b/drivers/gpu/drm/i915/display/intel_plane.c
index c181a7d063ec..11467d19399d 100644
--- a/drivers/gpu/drm/i915/display/intel_plane.c
+++ b/drivers/gpu/drm/i915/display/intel_plane.c
@@ -65,11 +65,11 @@
static void intel_plane_state_reset(struct intel_plane_state *plane_state,
struct intel_plane *plane)
{
memset(plane_state, 0, sizeof(*plane_state));
- __drm_atomic_helper_plane_state_reset(&plane_state->uapi, &plane->base);
+ __drm_atomic_helper_plane_state_init(&plane_state->uapi, &plane->base);
plane_state->scaler_id = -1;
plane_state->fence_id = -1;
}
diff --git a/include/drm/drm_atomic_state_helper.h b/include/drm/drm_atomic_state_helper.h
index 61a3b38ad49f..691c1ccfa4e0 100644
--- a/include/drm/drm_atomic_state_helper.h
+++ b/include/drm/drm_atomic_state_helper.h
@@ -51,11 +51,11 @@ struct drm_crtc_state *
drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc);
void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state);
void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
struct drm_crtc_state *state);
-void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *state,
+void __drm_atomic_helper_plane_state_init(struct drm_plane_state *state,
struct drm_plane *plane);
void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
struct drm_plane_state *state);
void drm_atomic_helper_plane_reset(struct drm_plane *plane);
void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
--
2.54.0
^ permalink raw reply related
* [PATCH v5 08/19] drm/atomic-state-helper: Fix __drm_atomic_helper_plane_reset() doc typo
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
A typo has slipped through in the __drm_atomic_helper_plane_reset()
documentation, probably due to copy and paste. It will not assign
drm_crtc state pointer, but rather the drm_plane's.
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_atomic_state_helper.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index a82568d87e4f..c8ccf8be5074 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -303,11 +303,11 @@ EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);
* __drm_atomic_helper_plane_reset - reset state on plane
* @plane: drm plane
* @plane_state: plane state to assign
*
* Initializes the newly allocated @plane_state and assigns it to
- * the &drm_crtc->state pointer of @plane, usually required when
+ * the &drm_plane->state pointer of @plane, usually required when
* initializing the drivers or when called from the &drm_plane_funcs.reset
* hook.
*
* This is useful for drivers that subclass the plane state.
*/
--
2.54.0
^ permalink raw reply related
* [PATCH 6/8] drm: atmel-hlcdc: add XLCDC clock bypass support for small dividers
From: Manikandan Muralidharan @ 2026-05-19 9:01 UTC (permalink / raw)
To: maarten.lankhorst, mripard, tzimmermann, airlied, simona,
nicolas.ferre, alexandre.belloni, claudiu.beznea, lee, dri-devel,
linux-arm-kernel, linux-kernel
Cc: manikandan.m
In-Reply-To: <20260519090135.1188405-1-manikandan.m@microchip.com>
Define ATMEL_XLCDC_CLKBYP and set the clock bypass bit on XLCDC
hardware when the computed divider is less than 2, avoiding an
invalid divider value. Non-XLCDC hardware retains the existing
minimum divider clamp of 2.
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 7 +++++++
include/linux/mfd/atmel-hlcdc.h | 1 +
2 files changed, 8 insertions(+)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index 6da428361c19..f837684654ea 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -87,6 +87,13 @@ static int atmel_hlcdc_crtc_setup_clock(struct atmel_hlcdc_crtc *crtc,
div = DIV_ROUND_CLOSEST(prate, mode_rate);
if (div < 2) {
+ /* XLCDC: bypass divider when div < 2 */
+ if (crtc->dc->desc->is_xlcdc) {
+ *cfg |= ATMEL_XLCDC_CLKBYP;
+ *mask |= ATMEL_XLCDC_CLKBYP;
+ return 0;
+ }
+ /* Enforce minimum divider for non-XLCDC */
div = 2;
} else if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK) {
/* The divider ended up too big, try a lower base rate. */
diff --git a/include/linux/mfd/atmel-hlcdc.h b/include/linux/mfd/atmel-hlcdc.h
index 8e86219293b7..1463c7db0e64 100644
--- a/include/linux/mfd/atmel-hlcdc.h
+++ b/include/linux/mfd/atmel-hlcdc.h
@@ -44,6 +44,7 @@
#define ATMEL_XLCDC_HEO_UPDATE BIT(3)
#define ATMEL_HLCDC_CLKPOL BIT(0)
+#define ATMEL_XLCDC_CLKBYP BIT(1)
#define ATMEL_HLCDC_CLKSEL BIT(2)
#define ATMEL_HLCDC_CLKPWMSEL BIT(3)
#define ATMEL_HLCDC_CGDIS(i) BIT(8 + (i))
--
2.25.1
^ permalink raw reply related
* [PATCH v5 06/19] drm/colorop: Rename __drm_colorop_state_reset()
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
__drm_colorop_state_reset() is used to initialize a newly allocated
drm_colorop_state, and is being typically called by drm_colorop_reset().
Since we want to consolidate DRM objects state allocation around the
atomic_create_state callback that will only allocate and initialize a
new drm_colorop_state instance, we will need to call
__drm_colorop_state_reset() from both the reset and atomic_create paths.
To avoid any confusion, we can thus rename __drm_colorop_state_reset()
to __drm_colorop_state_init().
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_colorop.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_colorop.c b/drivers/gpu/drm/drm_colorop.c
index 48d0b7ae3fc9..4c4d0a953e35 100644
--- a/drivers/gpu/drm/drm_colorop.c
+++ b/drivers/gpu/drm/drm_colorop.c
@@ -498,19 +498,19 @@ void drm_colorop_atomic_destroy_state(struct drm_colorop *colorop,
__drm_atomic_helper_colorop_destroy_state(state);
kfree(state);
}
/**
- * __drm_colorop_state_reset - resets colorop state to default values
+ * __drm_colorop_state_init - Initializes colorop state to default values
* @colorop_state: atomic colorop state, must not be NULL
* @colorop: colorop object, must not be NULL
*
* Initializes the newly allocated @colorop_state with default
* values. This is useful for drivers that subclass the colorop state.
*/
-static void __drm_colorop_state_reset(struct drm_colorop_state *colorop_state,
- struct drm_colorop *colorop)
+static void __drm_colorop_state_init(struct drm_colorop_state *colorop_state,
+ struct drm_colorop *colorop)
{
u64 val;
colorop_state->colorop = colorop;
colorop_state->bypass = true;
@@ -537,11 +537,11 @@ static void __drm_colorop_state_reset(struct drm_colorop_state *colorop_state,
*/
static void __drm_colorop_reset(struct drm_colorop *colorop,
struct drm_colorop_state *colorop_state)
{
if (colorop_state)
- __drm_colorop_state_reset(colorop_state, colorop);
+ __drm_colorop_state_init(colorop_state, colorop);
colorop->state = colorop_state;
}
void drm_colorop_reset(struct drm_colorop *colorop)
--
2.54.0
^ permalink raw reply related
* [PATCH v5 05/19] drm/mode-config: Document drm_private_obj exclusion from drm_mode_config_reset()
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
drm_mode_config_reset() does not reset drm_private_states by design.
This is especially significant for the DP MST and tunneling code that
expect to be preserved across a suspend/resume cycle, where
drm_mode_config_reset() is also used.
Document this expectation.
Link: https://lore.kernel.org/dri-devel/aOaQLx-7EpsHRwkH@ideak-desk/
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_mode_config.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index 66f7dc37b597..c33382a38191 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -187,10 +187,14 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
* @dev: drm device
*
* This functions calls all the crtc's, encoder's and connector's ->reset
* callback. Drivers can use this in e.g. their driver load or resume code to
* reset hardware and software state.
+ *
+ * Note that &drm_private_obj structures are expected to be stable across
+ * suspend/resume cycles, and drm_mode_config_reset() does not affect these
+ * structures.
*/
void drm_mode_config_reset(struct drm_device *dev)
{
struct drm_crtc *crtc;
struct drm_colorop *colorop;
--
2.54.0
^ permalink raw reply related
* [PATCH 5/8] drm: atmel-hlcdc: extract clock setup into a dedicated helper
From: Manikandan Muralidharan @ 2026-05-19 9:01 UTC (permalink / raw)
To: maarten.lankhorst, mripard, tzimmermann, airlied, simona,
nicolas.ferre, alexandre.belloni, claudiu.beznea, lee, dri-devel,
linux-arm-kernel, linux-kernel
Cc: manikandan.m
In-Reply-To: <20260519090135.1188405-1-manikandan.m@microchip.com>
Factor clock enable, rate calculation, and divider selection out of
atmel_hlcdc_crtc_mode_set_nofb() into a new
atmel_hlcdc_crtc_setup_clock() helper, preparing for the addition
of LVDS and XLCDC clock bypass support.
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
.../gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 66 +++++++++++--------
1 file changed, 39 insertions(+), 27 deletions(-)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index c7e77bb2941a..6da428361c19 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -66,6 +66,42 @@ drm_crtc_to_atmel_hlcdc_crtc(struct drm_crtc *crtc)
return container_of(crtc, struct atmel_hlcdc_crtc, base);
}
+static int atmel_hlcdc_crtc_setup_clock(struct atmel_hlcdc_crtc *crtc,
+ unsigned long mode_rate,
+ unsigned int *cfg,
+ unsigned int *mask)
+{
+ unsigned long prate;
+ int div, ret;
+
+ ret = clk_prepare_enable(crtc->dc->hlcdc->sys_clk);
+ if (ret)
+ return ret;
+
+ prate = clk_get_rate(crtc->dc->hlcdc->sys_clk);
+ if (!crtc->dc->desc->fixed_clksrc) {
+ prate *= 2;
+ *cfg |= ATMEL_HLCDC_CLKSEL;
+ *mask |= ATMEL_HLCDC_CLKSEL;
+ }
+
+ div = DIV_ROUND_CLOSEST(prate, mode_rate);
+ if (div < 2) {
+ div = 2;
+ } else if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK) {
+ /* The divider ended up too big, try a lower base rate. */
+ if (!crtc->dc->desc->fixed_clksrc) {
+ *cfg &= ~ATMEL_HLCDC_CLKSEL;
+ div = DIV_ROUND_CLOSEST(prate >> 1, mode_rate);
+ }
+ if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK)
+ div = ATMEL_HLCDC_CLKDIV_MAX;
+ }
+
+ *cfg |= ATMEL_HLCDC_CLKDIV(div);
+ return 0;
+}
+
static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
{
struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
@@ -76,12 +112,10 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
struct atmel_hlcdc_crtc_state *state;
struct drm_device *ddev = c->dev;
struct drm_connector_list_iter iter;
- unsigned long mode_rate;
struct videomode vm;
- unsigned long prate;
unsigned int mask = ATMEL_HLCDC_CLKDIV_MASK | ATMEL_HLCDC_CLKPOL;
unsigned int cfg = 0;
- int div, ret;
+ int ret;
/* get encoder from crtc */
drm_for_each_encoder(en_iter, ddev) {
@@ -100,33 +134,11 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
drm_connector_list_iter_end(&iter);
}
- ret = clk_prepare_enable(crtc->dc->hlcdc->sys_clk);
+ ret = atmel_hlcdc_crtc_setup_clock(crtc, adj->crtc_clock * 1000,
+ &cfg, &mask);
if (ret)
return;
- prate = clk_get_rate(crtc->dc->hlcdc->sys_clk);
- mode_rate = adj->crtc_clock * 1000;
- if (!crtc->dc->desc->fixed_clksrc) {
- prate *= 2;
- cfg |= ATMEL_HLCDC_CLKSEL;
- mask |= ATMEL_HLCDC_CLKSEL;
- }
-
- div = DIV_ROUND_CLOSEST(prate, mode_rate);
- if (div < 2) {
- div = 2;
- } else if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK) {
- /* The divider ended up too big, try a lower base rate. */
- if (!crtc->dc->desc->fixed_clksrc) {
- cfg &= ~ATMEL_HLCDC_CLKSEL;
- div = DIV_ROUND_CLOSEST(prate >> 1, mode_rate);
- }
- if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK)
- div = ATMEL_HLCDC_CLKDIV_MAX;
- }
-
- cfg |= ATMEL_HLCDC_CLKDIV(div);
-
if (connector &&
connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
cfg |= ATMEL_HLCDC_CLKPOL;
--
2.25.1
^ permalink raw reply related
* [PATCH 4/8] drm: atmel-hlcdc: define ATMEL_HLCDC_CLKDIV_MAX and fix divider fallback
From: Manikandan Muralidharan @ 2026-05-19 9:01 UTC (permalink / raw)
To: maarten.lankhorst, mripard, tzimmermann, airlied, simona,
nicolas.ferre, alexandre.belloni, claudiu.beznea, lee, dri-devel,
linux-arm-kernel, linux-kernel
Cc: manikandan.m
In-Reply-To: <20260519090135.1188405-1-manikandan.m@microchip.com>
Introduce ATMEL_HLCDC_CLKDIV_MAX to replace the raw mask.In the divider
overflow fallback, restrict the clock source switch and halved rate
retry to SoCs that support the 2x system clock path.
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 9 +++++----
include/linux/mfd/atmel-hlcdc.h | 1 +
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index f30138da1ed8..c7e77bb2941a 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -117,11 +117,12 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
div = 2;
} else if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK) {
/* The divider ended up too big, try a lower base rate. */
- cfg &= ~ATMEL_HLCDC_CLKSEL;
- prate /= 2;
- div = DIV_ROUND_CLOSEST(prate, mode_rate);
+ if (!crtc->dc->desc->fixed_clksrc) {
+ cfg &= ~ATMEL_HLCDC_CLKSEL;
+ div = DIV_ROUND_CLOSEST(prate >> 1, mode_rate);
+ }
if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK)
- div = ATMEL_HLCDC_CLKDIV_MASK;
+ div = ATMEL_HLCDC_CLKDIV_MAX;
}
cfg |= ATMEL_HLCDC_CLKDIV(div);
diff --git a/include/linux/mfd/atmel-hlcdc.h b/include/linux/mfd/atmel-hlcdc.h
index 07c2081867fd..8e86219293b7 100644
--- a/include/linux/mfd/atmel-hlcdc.h
+++ b/include/linux/mfd/atmel-hlcdc.h
@@ -50,6 +50,7 @@
#define ATMEL_HLCDC_CLKDIV_SHFT 16
#define ATMEL_HLCDC_CLKDIV_MASK GENMASK(23, 16)
#define ATMEL_HLCDC_CLKDIV(div) ((div - 2) << ATMEL_HLCDC_CLKDIV_SHFT)
+#define ATMEL_HLCDC_CLKDIV_MAX ((ATMEL_HLCDC_CLKDIV_MASK >> ATMEL_HLCDC_CLKDIV_SHFT) + 2)
#define ATMEL_HLCDC_PIXEL_CLK BIT(0)
#define ATMEL_HLCDC_SYNC BIT(1)
--
2.25.1
^ permalink raw reply related
* [PATCH v5 03/19] drm/atomic: Drop drm_private_obj.state assignment from create_state
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
The initial intent of the atomic_create_state hook was to simply
allocate a proper drm_private_state and return it, without any side
effect.
However, __drm_atomic_helper_private_obj_create_state(), which most
atomic_create_state implementations call, introduces a side effect by
setting drm_private_obj.state to the newly allocated state.
This assignment defeats the purpose, but is also redundant since
drm_atomic_private_obj_init(), the only call site for the
atomic_create_state hook, will also set this pointer to the newly
allocated state.
Drop the assignment in __drm_atomic_helper_private_obj_create_state().
Fixes: e7be39ed1716 ("drm/atomic-helper: Add private_obj atomic_create_state helper")
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_atomic_state_helper.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index cc70508d4fdb..a82568d87e4f 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -729,12 +729,10 @@ EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
void __drm_atomic_helper_private_obj_create_state(struct drm_private_obj *obj,
struct drm_private_state *state)
{
if (state)
state->obj = obj;
-
- obj->state = state;
}
EXPORT_SYMBOL(__drm_atomic_helper_private_obj_create_state);
/**
* __drm_atomic_helper_private_obj_duplicate_state - copy atomic private state
--
2.54.0
^ permalink raw reply related
* [PATCH 3/8] drm: atmel-hlcdc: simplify clock divider selection with DIV_ROUND_CLOSEST
From: Manikandan Muralidharan @ 2026-05-19 9:01 UTC (permalink / raw)
To: maarten.lankhorst, mripard, tzimmermann, airlied, simona,
nicolas.ferre, alexandre.belloni, claudiu.beznea, lee, dri-devel,
linux-arm-kernel, linux-kernel
Cc: manikandan.m
In-Reply-To: <20260519090135.1188405-1-manikandan.m@microchip.com>
DIV_ROUND_CLOSEST naturally selects the nearest divider, making the
manual 10x proximity check redundant. Drop it and switch from
DIV_ROUND_UP accordingly.
Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 16 ++--------------
1 file changed, 2 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index 9673fbce42a7..f30138da1ed8 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -112,28 +112,16 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
mask |= ATMEL_HLCDC_CLKSEL;
}
- div = DIV_ROUND_UP(prate, mode_rate);
+ div = DIV_ROUND_CLOSEST(prate, mode_rate);
if (div < 2) {
div = 2;
} else if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK) {
/* The divider ended up too big, try a lower base rate. */
cfg &= ~ATMEL_HLCDC_CLKSEL;
prate /= 2;
- div = DIV_ROUND_UP(prate, mode_rate);
+ div = DIV_ROUND_CLOSEST(prate, mode_rate);
if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK)
div = ATMEL_HLCDC_CLKDIV_MASK;
- } else {
- int div_low = prate / mode_rate;
-
- if (div_low >= 2 &&
- (10 * (prate / div_low - mode_rate) <
- (mode_rate - prate / div)))
- /*
- * At least 10 times better when using a higher
- * frequency than requested, instead of a lower.
- * So, go with that.
- */
- div = div_low;
}
cfg |= ATMEL_HLCDC_CLKDIV(div);
--
2.25.1
^ permalink raw reply related
* [PATCH v5 04/19] drm/atomic: Expand atomic_create_state expectations for drm_private_obj
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
The atomic_create_state callback documentation for planes, CRTCs, and
connectors explicitly states the expected behaviour: the returned
state must not be assigned to the object's state pointer, and hardware
must not be touched.
The drm_private_state_funcs.atomic_create_state documentation is
missing this clarification. Add it for consistency.
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
include/drm/drm_atomic.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 1a80a8cdf269..88087910ab1a 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -263,11 +263,14 @@ struct drm_private_state;
struct drm_private_state_funcs {
/**
* @atomic_create_state:
*
* Allocates a pristine, initialized, state for the private
- * object and returns it.
+ * object and returns it. This callback must have no side
+ * effects: in particular, the returned state must not be
+ * assigned to the object's state pointer and it must not affect
+ * the hardware state.
*
* RETURNS:
*
* A new, pristine, private state instance or an error pointer
* on failure.
--
2.54.0
^ permalink raw reply related
* [PATCH v5 02/19] drm/colorop: Fix typos in the doc
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
In the documentation of drm_colorop introduced by commit cfc27680ee20
("drm/colorop: Introduce new drm_colorop mode object"), the
documentation of __drm_colorop_state_reset() and __drm_colorop_reset()
were mentioning CRTC when they really meant colorop, probably due to
copy and paste.
Fixes: cfc27680ee20 ("drm/colorop: Introduce new drm_colorop mode object")
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
drivers/gpu/drm/drm_colorop.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_colorop.c b/drivers/gpu/drm/drm_colorop.c
index 764d12060666..48d0b7ae3fc9 100644
--- a/drivers/gpu/drm/drm_colorop.c
+++ b/drivers/gpu/drm/drm_colorop.c
@@ -503,11 +503,11 @@ void drm_colorop_atomic_destroy_state(struct drm_colorop *colorop,
* __drm_colorop_state_reset - resets colorop state to default values
* @colorop_state: atomic colorop state, must not be NULL
* @colorop: colorop object, must not be NULL
*
* Initializes the newly allocated @colorop_state with default
- * values. This is useful for drivers that subclass the CRTC state.
+ * values. This is useful for drivers that subclass the colorop state.
*/
static void __drm_colorop_state_reset(struct drm_colorop_state *colorop_state,
struct drm_colorop *colorop)
{
u64 val;
@@ -526,14 +526,14 @@ static void __drm_colorop_state_reset(struct drm_colorop_state *colorop_state,
/**
* __drm_colorop_reset - reset state on colorop
* @colorop: drm colorop
* @colorop_state: colorop state to assign
*
- * Initializes the newly allocated @colorop_state and assigns it to
- * the &drm_crtc->state pointer of @colorop, usually required when
- * initializing the drivers or when called from the &drm_colorop_funcs.reset
- * hook.
+ * Initializes the newly allocated @colorop_state and assigns it to the
+ * &drm_colorop->state pointer of @colorop, usually required when
+ * initializing the drivers or when called from the
+ * &drm_colorop_funcs.reset hook.
*
* This is useful for drivers that subclass the colorop state.
*/
static void __drm_colorop_reset(struct drm_colorop *colorop,
struct drm_colorop_state *colorop_state)
--
2.54.0
^ permalink raw reply related
* [PATCH v5 01/19] drm/atomic: Document atomic commit lifetime
From: Maxime Ripard @ 2026-05-19 9:01 UTC (permalink / raw)
To: Maarten Lankhorst, Thomas Zimmermann, David Airlie, Simona Vetter,
Jonathan Corbet, Shuah Khan, Dmitry Baryshkov, Jyri Sarha,
Tomi Valkeinen, Andrzej Hajda, Neil Armstrong, Robert Foss,
Laurent Pinchart, Jonas Karlman, Jernej Skrabec, Simon Ser,
Harry Wentland, Melissa Wen, Sebastian Wick, Alex Hung,
Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin,
Chen-Yu Tsai, Samuel Holland, Dave Stevenson, Maíra Canal,
Raspberry Pi Kernel Maintenance
Cc: dri-devel, linux-doc, linux-kernel, Daniel Stone, intel-gfx,
intel-xe, linux-arm-kernel, linux-sunxi, Maxime Ripard,
Laurent Pinchart
In-Reply-To: <20260519-drm-mode-config-init-v5-0-388b03321e38@kernel.org>
How drm_atomic_commit and the various entity structures are allocated
and freed isn't really trivial. Document it.
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
Documentation/gpu/drm-kms.rst | 6 +++++
drivers/gpu/drm/drm_atomic.c | 58 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 64 insertions(+)
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index d22817fdf9aa..36d76e391074 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -282,10 +282,16 @@ structure, ordering of committing state changes to hardware is sequenced using
:c:type:`struct drm_crtc_commit <drm_crtc_commit>`.
Read on in this chapter, and also in :ref:`drm_atomic_helper` for more detailed
coverage of specific topics.
+Atomic State Lifetime
+---------------------
+
+.. kernel-doc:: drivers/gpu/drm/drm_atomic.c
+ :doc: state lifetime
+
Handling Driver Private State
-----------------------------
.. kernel-doc:: drivers/gpu/drm/drm_atomic.c
:doc: handling driver private state
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 170de30c28ae..d98586d89bbe 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -45,10 +45,68 @@
#include <drm/drm_colorop.h>
#include "drm_crtc_internal.h"
#include "drm_internal.h"
+/**
+ * DOC: state lifetime
+ *
+ * &struct drm_atomic_commit represents an update to video pipeline
+ * state. It's a transient object that holds a state update as a
+ * collection of pointers to individual objects' states. &struct
+ * drm_atomic_commit has a much shorter lifetime than the objects'
+ * states, since it's only allocated while preparing, checking or
+ * committing the update, while object states are allocated when
+ * preparing the update and kept alive as long as they are active in the
+ * device.
+ *
+ * Their respective lifetimes are:
+ *
+ * - at reset time, the object reset implementation will allocate a new
+ * default state and will store it in the object state pointer.
+ *
+ * - whenever a new update is needed:
+ *
+ * + A new &struct drm_atomic_commit is allocated using
+ * drm_atomic_commit_alloc().
+ *
+ * + The current active state of all entities affected by the update
+ * is copied into this new &struct drm_atomic_commit using
+ * drm_atomic_get_plane_state(), drm_atomic_get_crtc_state(),
+ * drm_atomic_get_connector_state(), or
+ * drm_atomic_get_private_obj_state(). This new state can then be
+ * modified.
+ *
+ * At that point, &struct drm_atomic_commit stores three state
+ * pointers for any affected entity: the "old" and "new" states, and
+ * state_to_destroy. The old state is the state currently active in
+ * the hardware, which is either the one initialized by reset() or a
+ * newer one if a commit has been made. The new state is the state
+ * we just allocated and we might eventually commit to the hardware.
+ * The state_to_destroy points to the state we'll eventually have to
+ * free when the drm_atomic_commit will be destroyed, and points to
+ * the new state for now since the old state is still the active
+ * state.
+ *
+ * + After the state is populated, it is checked. If the check is
+ * successful, the update is committed. Part of the commit is a call
+ * to drm_atomic_helper_swap_state() which will turn the new states
+ * into the active states. Doing so involves updating the object's
+ * state pointer (&drm_crtc.state or similar) to point to the new
+ * state, and state_to_destroy will now point to the old states,
+ * that used to be active but aren't anymore.
+ *
+ * + When the commit is done, and when all references to our &struct
+ * drm_atomic_commit are put, __drm_atomic_commit_free() is called.
+ * It will, in turn, call drm_atomic_commit_clear() that will free
+ * all state_to_destroy (ie. old states), and finally free &struct
+ * drm_atomic_commit instance.
+ *
+ * + Now, we don't have any active &struct drm_atomic_commit anymore,
+ * and only the entity active states remain allocated.
+ */
+
void __drm_crtc_commit_free(struct kref *kref)
{
struct drm_crtc_commit *commit =
container_of(kref, struct drm_crtc_commit, ref);
--
2.54.0
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