[PATCH v12 0/5] drm/atomic-helper: Re-order CRTC and Bridge ops
Tomi Valkeinen
tomi.valkeinen at ideasonboard.com
Mon May 26 10:40:39 UTC 2025
Hi Maxime, Maarten, Thomas,
On 16/05/2025 15:23, Tomi Valkeinen wrote:
> Hi all,
>
> On 06/04/2025 16:16, Aradhya Bhatia wrote:
>> Hello all,
>>
>> This series re-orders the sequences in which the drm CRTC and the drm
>> Bridge get enabled and disabled with respect to each other.
>>
>> The bridge pre_enable calls have been shifted before the crtc_enable and
>> the bridge post_disable calls have been shifted after the crtc_disable.
>>
>> This has been done as per the definition of bridge pre_enable.
>> "The display pipe (i.e. clocks and timing signals) feeding this bridge
>> will
>> not yet be running when this callback is called".
>>
>> Since CRTC is also a source feeding the bridge, it should not be enabled
>> before the bridges in the pipeline are pre_enabled.
>
> Any further comments to this?
>
> All the patches have been reviewed and tested. I can push this, along
> with the serieses that depend on this, via drm-misc, but I'll need an
> ack from a maintainer.
Would any of you have a moment to check this out and ack/apply? This
series is blocking further development on DSI and OLDI.
Tomi
>
> Tomi
>
>
>> The original sequence. for display pipe enable looks like:
>>
>> crtc_enable
>>
>> bridge[n]_pre_enable
>> ...
>> bridge[1]_pre_enable
>>
>> encoder_enable
>>
>> bridge[1]_enable
>> ...
>> bridge[n]_enable
>>
>> The sequence of enable after this patch-set will look like:
>>
>> bridge[n]_pre_enable
>> ...
>> bridge[1]_pre_enable
>>
>> crtc_enable
>> encoder_enable
>>
>> bridge[1]_enable
>> ...
>> bridge[n]_enable
>>
>>
>> For the disable sequence, this is what the original looks like:
>>
>> bridge[n]_disable
>> ...
>> bridge[1]_disable
>>
>> encoder_disable
>>
>> bridge[1]_post_disable
>> ...
>> bridge[n]_post_disable
>>
>> crtc_disable
>>
>> This is what the disable sequence will be, after this series of patches:
>>
>> bridge[n]_disable
>> ...
>> bridge[1]_disable
>>
>> encoder_disable
>> crtc_disable
>>
>> bridge[1]_post_disable
>> ...
>> bridge[n]_post_disable
>>
>> This series further updates the bridge API definitions to accurately
>> reflect the updated scenario.
>>
>> This series is a subset of its v11[0] which had 14 patches in the
>> revision.
>> 9 of those 14 patches (which were specific to the cdns-dsi bridge driver)
>> were merged[1].
>>
>> Regards
>> Aradhya
>>
>> ---
>> * Note on checkpatch warning in patch 2/4 *
>> Patch 2/4 causes the checkpatch to flare up for 1 checkpatch 'check' -
>>
>> CHECK: Lines should not end with a '('
>> #79: FILE: drivers/gpu/drm/drm_atomic_helper.c:1304:
>> + new_crtc_state = drm_atomic_get_new_crtc_state(
>>
>> This patch is largely duplicating the original code, with minor
>> differences to
>> perform different operations. This line of code pre-exists in the file
>> and
>> have simply been duplicated. I have decided to keep it as is to
>> maintain the
>> uniformity and the originally intended readability. Should perhaps a
>> fix be
>> required, this patch/series is not the right place, and another patch
>> can be
>> created to fix this across the whole file.
>>
>> References:
>> [0]: Revision v11 of this series.
>> https://lore.kernel.org/all/20250329113925.68204-1-
>> aradhya.bhatia at linux.dev/
>>
>> [1]: Patches 1 through 9 getting merged.
>> https://lore.kernel.org/
>> all/174335361171.2556605.12634785416741695829.b4-ty at oss.qualcomm.com/
>>
>>
>> ---
>> Change Log:
>>
>> - Changes in v12:
>> - Drop patches 1 through 9 since they have been merged.
>> - Rebase onto newer drm-misc-next.
>> - Re-word the patch 3/4, ("drm/bridge: Update the bridge enable/
>> disable doc")
>> to make it more readable.
>>
>> - Changes in v11:
>> - Add patch v11:13/14 ("drm/bridge: Update the bridge enable/
>> disable doc"),
>> that updates the documentation about the order of the various
>> bridge
>> enable/disable hooks being called wrt the CRTC and encoder hooks.
>> - Rebase on drm-misc-next instead of linux-next.
>> As part of rebase, accommodate the following change:
>> - Change patch v10:08/13 ("drm/bridge: cdns-dsi: Support atomic
>> bridge
>> APIs") to v11:08/13 ("drm/bridge: cdns-dsi: Add input format
>> negotiation"), since Maxime has already updated the bridge
>> hooks to
>> their atomic versions in commit 68c98e227a96 ("drm/bridge:
>> cdns-csi:
>> Switch to atomic helpers").
>> My new patch now only adds the format negotiation hook for
>> the cdns-dsi.
>> (Note: Since the new patch is now only a subset of the old
>> one, without
>> any change in logic, I decided to carry forward the R-b and
>> T-b tags.)
>> - Add Alexander Sverdlin's T-b in patches 10, 11, 12.
>>
>> - Changes in v10:
>> - Rebase on latest linux-next (next-20250226).
>> - As part of rebase, update the patches to accommodate a couple of
>> widespread changes in DRM Framework -
>> - All the ("drm/atomic-helper: Change parameter name of ***")
>> commits.
>> - All the ("drm/bridge: Pass full state to ***") commits.
>> (These updates are only trivial substitutions.)
>> - Add Tomi Valkeinen's T-b tags in all the patches.
>>
>> - Changes in v9:
>> - Fix the oops in 11/13 - where the encoder_bridge_enable _was_
>> pre_enabling
>> the bridges instead of enabling.
>> - Add the following tags:
>> - Dmitry Baryshkov's R-b in patches 2, 10, 11, and A-b in patch
>> 12.
>> - Jayesh Choudhary's R-b in patch 12.
>> - Tomi Valkeinen's R-b in patches 2, 10, 11, 12.
>>
>> - Changes in v8:
>> - Move the phy de-initialization to bridge post_disable() instead
>> of bridge
>> disable() in patch-3.
>> - Copy the private bridge state (dsi_cfg), in addition to the
>> bridge_state,
>> in patch-9.
>> - Split patch v7:11/12 into three patches, v8:{10,11,12}/13, to
>> separate out
>> different refactorings into different patches, and improve
>> bisectability.
>> - Move patch v7:02/12 down to v8:06/12, to keep the initial
>> patches for
>> fixes only.
>> - Drop patch v7:04/12 as it doesn't become relevant until patch
>> v7:12/12.
>> - Add R-b tags of Dmitry Baryshkov in patch-9 and patch-3, and of
>> Tomi Valkeinen in patch-9.
>> - Changes in v7:
>> - phy_init()/exit() were called from the PM path in v6. Change it
>> back to
>> the bridge enable/disable path in patch-3, so that the
>> phy_init() can go
>> back to being called after D-Phy reset assert.
>> - Reword commit text in patch-5 to explain the need of the fix.
>> - Drop the stray code in patch-10.
>> - Add R-b tag of Dmitry Baryshkov in patch-6.
>>
>> - Changes in v6:
>> - Reword patch 3 to better explain the fixes around phy de-init.
>> - Fix the Lane ready timeout condition in patch 7.
>> - Fix the dsi _bridge_atomic_check() implementation by adding a new
>> bridge state structure in patch 10.
>> - Rework and combine patches v5:11/13 and v5:12/13 to v6:11/12.
>> - Generate the patches of these series using the "patience"
>> algorithm.
>> Note: All patches, except v6:11/12, *do not* differ from their
>> default
>> (greedy) algorithm variants.
>> For patch 11, the patience algorithm significantly improves the
>> readability.
>> - Rename and move the Bridge enable/disable enums from public to
>> private
>> in patch 11.
>> - Add R-b tags of Tomi Valkeinen in patch 6, and Dmitry Baryshkov
>> in patch 2.
>>
>> - Changes in v5:
>> - Fix subject and description in patch 1/13.
>> - Add patch to check the return value of
>> phy_mipi_dphy_get_default_config() (patch: 6/13).
>> - Change the Clk and Data Lane ready timeout from forever to 5s.
>> - Print an error instead of calling WARN_ON_ONCE in patch 7/13.
>> - Drop patch v4-07/11: "drm/bridge: cdns-dsi: Reset the DCS write
>> FIFO".
>> There has been some inconsistencies found with this patch upon
>> further
>> testing. This patch was being used to enable a DSI panel based
>> on ILITEK
>> ILI9881C bridge. This will be debugged separately.
>> - Add patch to move the DSI mode check from _atomic_enable() to
>> _atomic_check() (patch: 10/13).
>> - Split patch v4-10/11 into 2 patches - 11/13 and 12/13.
>> Patch 11/13 separates out the Encoder-Bridge operations into a
>> helper
>> function *without* changing the logic. Patch 12/13 then changes
>> the order
>> of the encoder-bridge operations as was intended in the
>> original patch.
>> - Add detailed comment for patch 13/13.
>> - Add Tomi Valkeinen's R-b in patches 1, 2, 4, 5, 7, 8, 9, 13.
>>
>> - Changes in v4:
>> - Add new patch, "drm/bridge: cdns-dsi: Move to
>> devm_drm_of_get_bridge()",
>> to update to an auto-managed way of finding next bridge in the
>> chain.
>> - Drop patch "drm/bridge: cdns-dsi: Fix the phy_initialized
>> variable" and
>> add "drm/bridge: cdns-dsi: Fix Phy _init() and _exit()" that
>> properly
>> de-initializes the Phy and maintains the initialization state.
>> - Reword patch "drm/bridge: cdns-dsi: Reset the DCS write FIFO"
>> to explain
>> the HW concerns better.
>> - Add R-b tag from Dmitry Baryshkov for patches 1/11 and 8/11.
>>
>> - Changes in v3:
>> - Reword the commit message for patch "drm/bridge: cdns-dsi: Fix
>> OF node
>> pointer".
>> - Add a new helper API to figure out DSI host input pixel format
>> in patch "drm/mipi-dsi: Add helper to find input format".
>> - Use a common function for bridge pre-enable and enable, and
>> bridge disable
>> and post-disable, to avoid code duplication.
>> - Add T-b tag from Dominik Haller in patch 5/10. (Missed to add
>> it in v2).
>> - Add R-b tag from Dmitry Baryshkov for patch 8/10.
>>
>> - Changes in v2:
>> - Drop patch "drm/tidss: Add CRTC mode_fixup"
>> - Split patch "drm/bridge: cdns-dsi: Fix minor bugs" into 4
>> separate ones
>> - Drop support for early_enable/late_disable APIs and instead re-
>> order the
>> pre_enable / post_disable APIs to be called before / after
>> crtc_enable /
>> crtc_disable.
>> - Drop support for early_enable/late_disable in cdns-dsi and use
>> pre_enable/post_disable APIs instead to do bridge enable/disable.
>>
>>
>> Previous versions:
>>
>> v1: https://lore.kernel.org/all/20240511153051.1355825-1-a-
>> bhatia1 at ti.com/
>> v2: https://lore.kernel.org/all/20240530093621.1925863-1-a-
>> bhatia1 at ti.com/
>> v3: https://lore.kernel.org/all/20240617105311.1587489-1-a-
>> bhatia1 at ti.com/
>> v4: https://lore.kernel.org/all/20240622110929.3115714-1-a-
>> bhatia1 at ti.com/
>> v5: https://lore.kernel.org/all/20241019195411.266860-1-
>> aradhya.bhatia at linux.dev/
>> v6: https://lore.kernel.org/all/20250111192738.308889-1-
>> aradhya.bhatia at linux.dev/
>> v7: https://lore.kernel.org/all/20250114055626.18816-1-
>> aradhya.bhatia at linux.dev/
>> v8: https://lore.kernel.org/all/20250126191551.741957-1-
>> aradhya.bhatia at linux.dev/
>> v9: https://lore.kernel.org/all/20250209121032.32655-1-
>> aradhya.bhatia at linux.dev/
>> v10: https://lore.kernel.org/all/20250226155228.564289-1-
>> aradhya.bhatia at linux.dev/
>> v11: https://lore.kernel.org/all/20250329113925.68204-1-
>> aradhya.bhatia at linux.dev/
>>
>> ---
>>
>> Aradhya Bhatia (5):
>> drm/atomic-helper: Refactor crtc & encoder-bridge op loops into
>> separate functions
>> drm/atomic-helper: Separate out bridge pre_enable/post_disable from
>> enable/disable
>> drm/atomic-helper: Re-order bridge chain pre-enable and post-disable
>> drm/bridge: Update the bridge enable/disable doc
>> drm/bridge: cdns-dsi: Use pre_enable/post_disable to enable/disable
>>
>> .../gpu/drm/bridge/cadence/cdns-dsi-core.c | 64 +++--
>> drivers/gpu/drm/drm_atomic_helper.c | 160 +++++++++--
>> include/drm/drm_bridge.h | 249 +++++++++++++-----
>> 3 files changed, 355 insertions(+), 118 deletions(-)
>>
>>
>> base-commit: dd717762761807452ca25634652e180a80349cd8
>
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