Add to_intel_uncore() function to avoid the inclusion of i915_drv.h from
intel_de.h. This reveals a number of implicit dependencies on i915_drv.h
that need to be added.
For now, to_intel_uncore() can be an inline function, with all the
includes in compat intel_uncore.h, as long as i915_drv.h isn't
included. The implicit dependencies on i915_drv.h is a problem in
display code, but the same is not true for xe_device.h etc.
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/377e2b400d126776224fc49874ed9cb03ac3123c.1732104170.git.jani.nikula@intel.com
We need to be able to do both MMIO and DSB based pipe/plane
programming. To that end plumb the 'dsb' all way from the top
into the plane commit hooks.
The compiler appears smart enough to combine the branches from
all the back-to-back register writes into a single branch.
So the generated asm ends up looking more or less like this:
plane_hook()
{
if (dsb) {
intel_dsb_reg_write();
intel_dsb_reg_write();
...
} else {
intel_de_write_fw();
intel_de_write_fw();
...
}
}
which seems like a reasonably efficient way to do this.
An alternative I was also considering is some kind of closure
(register write function + display vs. dsb pointer passed to it).
That does result is smaller code as there are no branches anymore,
but having each register access go via function pointer sounds
less efficient.
Not that I actually measured the overhead of either approach yet.
Also the reg_rw tracepoint seems to be making a huge mess of the
generated code for the mmio path. And additionally there's some
kind of IS_GSI_REG() hack in __raw_uncore_read() which ends up
generating a pointless branch for every mmio register access.
So looks like there might be quite a bit of room for improvement
in the mmio path still.
Reviewed-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240930170415.23841-12-ville.syrjala@linux.intel.com
In case of legacy cursor update, the cursor VMA needs to be unpinned
only after vblank. This exceeds the lifetime of the whole atomic commit.
Any trick I attempted to keep the atomic commit alive didn't work, as
drm_atomic_helper_setup_commit() force throttles on any old commit that
wasn't cleaned up.
The only option remaining is to remove the plane from the atomic commit,
and use the same path as the legacy cursor update to clean the state
after vblank.
Changes since previous version:
- Call the memset for plane state immediately when scheduling vblank,
this prevents a use-after-free in cursor cleanup.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522053341.137592-4-maarten.lankhorst@linux.intel.com
The cursor hardware only does sync updates, and thus the hardware
will be scanning out from the old fb until the next start of vblank.
So in order to make the legacy cursor fastpath actually safe we
should not unpin the old fb until we're sure the hardware has
ceased accessing it. The simplest approach is to just use a vblank
work here to do the delayed unpin.
Not 100% sure it's a good idea to put this onto the same high
priority vblank worker as eg. our timing critical gamma updates.
But let's keep it simple for now, and it we later discover that
this is causing problems we can think about adding a lower
priority worker for such things.
This patch is slightly reworked by Maarten
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522053341.137592-3-maarten.lankhorst@linux.intel.com
Different hardware generations have different scanout alignment
requirements. Introduce a new vfunc that will allow us to
make that distinction without horrible if-ladders.
For now we directly plug in the existing intel_surf_alignment()
and intel_cursor_alignment() functions.
For fbdev we (temporarily) introduce intel_fbdev_min_alignment()
that simply queries the alignment from the primary plane of
the first crtc.
TODO: someone will need to fix xe's alignment handling
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240612204712.31404-4-ville.syrjala@linux.intel.com
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Lets unify both bigjoiner and ultrajoiner under simple "joiner" name,
because in future we might have multiple configurations, involving
multiple bigjoiners, ultrajoiner, however it is possible to use
same api for handling both.
v2: - Renamed back some bigjoiner specific parts for now(Ville)
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
[vsyrjala: Catch a few more cases]
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240607075457.15700-1-stanislav.lisovskiy@intel.com
PIPESRC_ERLY_TPT is a pipe register, and it lives in the 0x70000 range.
so using _MMIO_TRANS2() for it is not really correct. Also since this
is a pipe register, and not present on CHV, the registers will be
equally spaced out, so we can use the simpler _MMIO_PIPE() instead
of _MMIO_PIPE2().
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240516135622.3498-5-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Split the cursor stuff from the rest of the selective fetch
plane registers so that we can collect all cursor registers
in intel_cursor_regs.h. Also take the opportunity to rename
the registers to match the spec.
v2: Pass the correct register offset fpr pipe B (Jani)
s/mtl+/tgl+/ as that's where this was introduced
Drop the bogus SEL_FETCH_CUR_CTL_ENABLE bit, the contents
actually match the normal CUR_CTL register
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240520171459.9661-1-ville.syrjala@linux.intel.com
Having the plane WM/DDB regitster write functions in skl_watermarks.c
is rather annoying when trying to implement DSB based plane updates.
Move them into the respective files that handle all other plane
register writes. Less places where I need to worry about the DSB
vs. MMIO decisions.
The downside is that we spread the wm struct details a bit further
afield. But if that becomes too annoying we can probably abstract
things a bit more with a few extra functions.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240510152329.24098-17-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
drm-misc-next for v6.10-rc1:
UAPI Changes:
- Add SIZE_HINTS property for cursor planes.
Cross-subsystem Changes:
Core Changes:
- Document the requirements and expectations of adding new
driver-specific properties.
- Assorted small fixes to ttm.
- More Kconfig fixes.
- Add struct drm_edid_product_id and helpers.
- Use drm device based logging in more drm functions.
- Fixes for drm-panic, and option to test it.
- Assorted small fixes and updates to edid.
- Add drm_crtc_vblank_crtc and use it in vkms, nouveau.
Driver Changes:
- Assorted small fixes and improvements to bridge/imx8mp-hdmi-tx, nouveau, ast, qaic, lima, vc4, bridge/anx7625, mipi-dsi.
- Add drm panic to simpledrm, mgag200, imx, ast.
- Use dev_err_probe in bridge/panel drivers.
- Add Innolux G121X1-L03, LG sw43408 panels.
- Use struct drm_edid in i915 bios parsing.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/2dc1b7c6-1743-4ddd-ad42-36f700234fbe@linux.intel.com
Advertize more suitable cursor sizes via the new SIZE_HINTS
plane property.
We can't really enumerate all supported cursor sizes on
the platforms where the cursor height can vary freely, so
for simplicity we'll just expose all square+POT sizes between
each platform's min and max cursor limits.
Depending on the platform this will give us one of three
results:
- 64x64,128x128,256x256,512x512
- 64x64,128x128,256x256
- 64x64
Cc: Simon Ser <contact@emersion.fr>
Cc: Jonas Ådahl <jadahl@redhat.com>
Cc: Daniel Stone <daniel@fooishbar.org>
Cc: Sameer Lattannavar <sameer.lattannavar@intel.com>
Cc: Sebastian Wick <sebastian.wick@redhat.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240318204408.9687-3-ville.syrjala@linux.intel.com
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Calling i915_gem_object_get_dma_address() from the vblank
evade critical section triggers might_sleep().
While we know that we've already pinned the framebuffer
and thus i915_gem_object_get_dma_address() will in fact
not sleep in this case, it seems reasonable to keep the
unconditional might_sleep() for maximum coverage.
So let's instead pre-populate the dma address during
fb pinning, which all happens before we enter the
vblank evade critical section.
We can use u32 for the dma address as this class of
hardware doesn't support >32bit addresses.
Cc: stable@vger.kernel.org
Fixes: 0225a90981 ("drm/i915: Make cursor plane registers unlocked")
Reported-by: Borislav Petkov <bp@alien8.de>
Closes: https://lore.kernel.org/intel-gfx/20240227100342.GAZd2zfmYcPS_SndtO@fat_crate.local/
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240325175738.3440-1-ville.syrjala@linux.intel.com
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
(cherry picked from commit c1289a5c35)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Calling i915_gem_object_get_dma_address() from the vblank
evade critical section triggers might_sleep().
While we know that we've already pinned the framebuffer
and thus i915_gem_object_get_dma_address() will in fact
not sleep in this case, it seems reasonable to keep the
unconditional might_sleep() for maximum coverage.
So let's instead pre-populate the dma address during
fb pinning, which all happens before we enter the
vblank evade critical section.
We can use u32 for the dma address as this class of
hardware doesn't support >32bit addresses.
Cc: stable@vger.kernel.org
Fixes: 0225a90981 ("drm/i915: Make cursor plane registers unlocked")
Reported-by: Borislav Petkov <bp@alien8.de>
Closes: https://lore.kernel.org/intel-gfx/20240227100342.GAZd2zfmYcPS_SndtO@fat_crate.local/
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240325175738.3440-1-ville.syrjala@linux.intel.com
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Our legacy cursor updates are actually mailbox updates.
Ie. the hardware latches things once per frame on start of
vblank, but we issue an number of updates per frame,
withough any attempt to synchronize against the vblank
in software. So in theory only the last update issued
during the frame will latch, and the previous ones are
discarded.
However this can lead to problems with maintaining the
ggtt/iommu mappings as we have no idea which updates
will actually latch.
The problem is exacerbated by the hardware's annoying disarming
behaviour; any non-arming register write will disarm an already
armed update, only to be rearmed later by the arming register
(CURBASE in case of cursors). If a disarming write happens
just before the start of vblank, and the arming write happens
after start of vblank we have effectively prevented the hardware
from latching anything. And if we manage to straddle multiple
sequential vblank starts in this manner we effectively prevent
the hardware from latching any new registers for an arbitrary
amount of time. This provides more time for the (potentially
still in use by the hardware) gtt/iommu mappings to be torn
down.
A partial solution, of course, is to use vblank evasion to
avoid the register writes from spreading on both sides of
the start of vblank.
I've previously highlighted this problem as a general issue
affecting mailbox updates. I even added some notes to the
{i9xx,skl}_crtc_planes_update_arm() to remind us that the noarm
and arm phases both need to pulled into the vblank evasion
critical section if we actually decided to implement mailbox
updates in general. But as I never impelemented the noarm+arm
split for cursors we don't have to worry about that for the
moment.
We've been lucky enough so far that this hasn't really caused
problems. One thing that does help is that Xorg generally
sticks to the same cursor BO. But igt seems pretty good at
hitting this on MTL now, so apparently we have to start
thinking about this.
v2: Wait for PSR exit to avoid the vblank evasion timeout (1ms)
tripping due to PSR exit latency (~5ms typically)
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240116204927.23499-1-ville.syrjala@linux.intel.com
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
New register CUR_POS_ERLY_TPT related to early transport is
supposed to be configured when early transport is in use.
This register is used to configure cursor vertical postion
from beginning of selective update area.
Bspec: 68927
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231218175004.52875-5-jouni.hogander@intel.com
Currently we are enabling selective fetch for all planes that are visible.
This is suboptimal as we might be fetching for memory for planes that are
not part of selective update.
Fix this by adding proper handling for disabling plane selective fetch:
If plane previously part of selective update is now not part of update:
Add it into updated planes and let the plane configuration to disable
selective fetch for it.
v3: Checkpatch warnings fixed
v2:
- Add setting sel_fetch_area->y1/y2 to -1
- Remove setting again local sel_fetch_area variable
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231120082606.3156488-3-jouni.hogander@intel.com
Currently selective fetch configuration for planes is implemented in psr
code. More suitable place for this code is where everything else is
configured for planes -> move it into skl_universal_plane.c and
intel_cursor.c. This also allows us to drop hooks for cursor handling.
v3: Checkpatch warnings fixed
v2: Removed setting sel_fetch_area->y1/y2 as -1
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231120082606.3156488-2-jouni.hogander@intel.com
Move the runtime info specific to display into display-specific
structures as has already been done with the constant display info.
v2:
- Rename __runtime to __runtime_defaults for more clarity on the
purpose. (Andrzej)
- Move introduction of DISPLAY_INFO() to previous patch. (Andrzej)
- Drop NO_DISPLAY macro. (Andrzej)
v3:
- Use "{}" instead of "{ 0 }" for empty struct init. (Jani)
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230523195609.73627-4-matthew.d.roper@intel.com
Rather than embeddeding the display's device info within the main device
info structure, just provide a pointer to the display-specific
structure. This is in preparation for moving the display device info
definitions into the display code itself and for eventually allowing the
pointer to be assigned at runtime on platforms that use GMD_ID for
device identification.
In the future, this will also eventually allow the same display device
info structures to be used outside the current i915 code (e.g., from the
Xe driver).
v2:
- Move introduction of DISPLAY_INFO() to this patch. (Andrzej)
v3:
- Also use DISPLAY_INFO() in intel_display_reg_defs.h. (Andrzej)
- Use "{}" instead of "{ 0 }" for empty struct init. (Jani)
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230523195609.73627-3-matthew.d.roper@intel.com
SEL_FETCH_CTL registers are armed immediately when plane is disabled.
SEL_FETCH_* instances of plane configuration are used when doing
selective update and normal plane register instances for full updates.
Currently all SEL_FETCH_* registers are written as a part of noarm
plane configuration. If noarm and arm plane configuration are not
happening within same vblank we may end up having plane as a part of
selective update before it's PLANE_SURF register is written.
Fix this by splitting plane selective fetch configuration into arm and
noarm versions and call them accordingly. Write SEL_FETCH_CTL in arm
version.
v3:
- add arm suffix into intel_psr2_disable_plane_sel_fetch
v2:
- drop color_plane parameter from arm part
- dev_priv -> i915 in arm part
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Cc: Vinod Govindapillai <vinod.govindapillai@intel.com>
Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Cc: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230130080651.3796929-1-jouni.hogander@intel.com
Turns out many of the files that need i915_reg.h get it implicitly via
{display/intel_de.h, gt/intel_context.h} -> i915_trace.h -> i915_irq.h
-> i915_reg.h. Since i915_trace.h doesn't actually need i915_irq.h,
makes sense to drop it, but that requires adding quite a few new
includes all over the place.
Prefer including i915_reg.h where needed instead of adding another
implicit include, because eventually we'll want to split up i915_reg.h
and only include the specific registers at each place.
Also some places actually needed i915_irq.h too.
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/6e78a2e0ac1bffaf5af3b5ccc21dff05e6518cef.1668008071.git.jani.nikula@intel.com
Replace the somewhat obscure crtc_state.update_pipe checks
with a more descriptive thing. Also nicely matches the
intel_crtc_needs_modeset() counterpart for full modesets.
v2: Handle one more case in the fbc code
Reviewed-by: Jani Nikula <jani.nikula@intel.com> #v1
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221021162442.27283-2-ville.syrjala@linux.intel.com
Pull all the skl+ watermark code (and the dbuf/sagv/ipc code
since it's all sort of intertwined and I'm too lazy to think
of a finer grained split right now) into its own file from the
catch-all intel_pm.c.
Also sneak in the s/dev_priv/i915/ rename while at it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220908191646.20239-3-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
The macro DRM_PLANE_HELPER_NO_SCALING is only useful with the interfaces
in drm_atomic_helper.h, but defined in drm_plane_helper.h. So half of
DRM includes the latter header file for using this macro. Move the macro
and remove the include statements.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220720083058.15371-3-tzimmermann@suse.de
drm_crtc.h has no need for drm_blend.h, so don't include it.
Avoids useless rebuilds of the entire universe when
touching drm_blend.h.
Quite a few placs do currently depend on drm_blend.h without
actually including it directly. All of those need to be fixed
up.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220613200317.11305-4-ville.syrjala@linux.intel.com
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
When using bigjoiner it's useful to know the offset of each
individual pipe in the whole set of joined pipes. Let's include
that information in our PIPESRC rectangle. With this we can make
the plane clipping code blissfully unaware of bigjoiner usage, as
all we have to do is remove the pipe's offset from the final plane
destination coordinates.
v2: Use intel_bigjoiner_num_pipes()
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220223131315.18016-14-ville.syrjala@linux.intel.com
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Since we now have the bigjoiner_pipes bitmask the boolean
is redundant. Get rid of it.
Also, populating bigjoiner_pipes already during
encoder->compute_config() allows us to use it much earlier
during the state calculation as well. The initial aim is
to use it in intel_crtc_compute_config().
v2: Move the hweight(bigjoiner_pipes) stuff to a later patch
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com> #v1
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com> #v1
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220223131315.18016-12-ville.syrjala@linux.intel.com
Instead of just having the pipe_src_{w,h} let's use a full
drm_rect for it. This will be particularly useful to astract
away some bigjoiner details.
v2: No hweight() stuff yet
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220223131315.18016-11-ville.syrjala@linux.intel.com
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Adjust the cursor dst coordinates appripriately when it's on
the bigjoiner slave pipe. intel_atomic_plane_check_clipping()
already did this but with the cursor we discard those results
(apart from uapi.visible and error checks) since the hardware
will be doing the clipping for us.
v2: Rebase due to bigjoiner bitmask usage
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220223131315.18016-3-ville.syrjala@linux.intel.com
Drop the locks around cursor plane register writes. The
lock isn't needed since each plane's register are neatly
contained on their own cachelines.
The locking did have a secondary effect of disabling
interrupts around the cursor registers writes though.
If we drop that then we open outselves up for sceduling
delays and whatnot while on the middle of the register
writes. That increases the chance of not all the register
writes land during the same frame. For normal atomic
commits this is not a concern as the vblank evade mechanism
anyway disables interrupts around the update, but the legacy
cursor codepath does not. Technically we should do a vblank
evade there as well, but so far no one has bothered to hook
that up. So in the meantime let's put an explicit local irq
disable/enable around the legacy cursor update to keep the
race window minimal.
v2: local_irq_{disable,enable}() for legacy cursor ioctl
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220211092604.393-1-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
