The ssd130x DRM driver also makes use of this Device Tree binding to allow
existing users of the fbdev driver to migrate without the need to change
their Device Trees.

Add myself as another maintainer of the binding, to make sure that I will
be on Cc when patches are proposed for it.
Suggested-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NJavier Martinez Canillas <javierm@redhat.com>
Acked-by: NRob Herring <robh@kernel.org>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133935.3278933-1-javierm@redhat.com

To make sure that tools like the get_maintainer.pl script will suggest
to Cc me if patches are posted for this driver.

Also include the Device Tree binding for the old ssd1307fb fbdev driver
since the new DRM driver was made compatible with the existing binding.
Signed-off-by: NJavier Martinez Canillas <javierm@redhat.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133915.3278886-1-javierm@redhat.com

The ssd130x driver only provides the core support for these devices but it
does not have any bus transport logic. Add a driver to interface over I2C.
Signed-off-by: NJavier Martinez Canillas <javierm@redhat.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133710.3278506-5-javierm@redhat.com

This adds a DRM driver for SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
OLED display controllers.

It's only the core part of the driver and a bus specific driver is needed
for each transport interface supported by the display controllers.
Signed-off-by: NJavier Martinez Canillas <javierm@redhat.com>
Reviewed-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133710.3278506-4-javierm@redhat.com

Add support to convert from XR24 to reversed monochrome for drivers that
control monochromatic display panels, that only have 1 bit per pixel.

The function does a line-by-line conversion doing an intermediate step
first from XR24 to 8-bit grayscale and then to reversed monochrome.

The drm_fb_gray8_to_mono_reversed_line() helper was based on code from
drivers/gpu/drm/tiny/repaper.c driver.
Signed-off-by: NJavier Martinez Canillas <javierm@redhat.com>
Reviewed-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133710.3278506-3-javierm@redhat.com

Pull the per-line conversion logic into a separate helper function.

This will allow to do line-by-line conversion in other helpers that
convert to a gray8 format.
Suggested-by: NThomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: NJavier Martinez Canillas <javierm@redhat.com>
Reviewed-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133710.3278506-2-javierm@redhat.com

There is no object id in drm_display_mode anymore.
Remove stale comments to the contrary.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209091928.14766-2-ville.syrjala@linux.intel.comAcked-by: NMaxime Ripard <maxime@cerno.tech>

Use of_device_get_match_data() to simplify the code.
Reported-by: NZeal Robot <zealci@zte.com.cn>
Signed-off-by: NMinghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>
Signed-off-by: NMaxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214020530.1714631-1-chi.minghao@zte.com.cn

Recently we added generic "edp-panel"s probed by EDID. To support
panels in this way we look at the panel ID in the EDID and look up the
panel in a table that has power sequence timings. If we find a panel
that's not in the table we will still attempt to use it but we'll use
conservative timings. While it's likely that these conservative
timings will work for most nearly all panels, the performance of
turning the panel off and on suffers.

We'd like to be able to reliably detect the case that we're using the
hardcoded timings without relying on parsing dmesg. This allows us to
implement tests that ensure that no devices get shipped that are
relying on the conservative timings.

Let's add a new debugfs entry to panel devices. It will have one of:
* UNKNOWN - We tried to detect a panel but it wasn't in our table.
* HARDCODED - We're not using generic "edp-panel" probed by EDID.
* A panel name - This is the name of the panel from our table.
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204161245.v2.3.I209d72bcc571e1d7d6b793db71bf15c9c0fc9292@changeid

We'd like panels to be able to add things to debugfs underneath the
connector's directory. Let's plumb it through. A panel will be able to
put things in a "panel" directory under the connector's
directory. Note that debugfs is not ABI and so it's always possible
that the location that the panel gets for its debugfs could change in
the future.

NOTE: this currently only works if you're using a modern
architecture. Specifically the plumbing relies on _both_
drm_bridge_connector and drm_panel_bridge. If you're not using one or
both of these things then things won't be plumbed through.

As a side effect of this change, drm_bridges can also get callbacks to
put stuff underneath the connector's debugfs directory. At the moment
all bridges in the chain have their debugfs_init() called with the
connector's root directory.
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204161245.v2.2.Ib0bd5346135cbb0b63006b69b61d4c8af6484740@changeid

The ti-sn65dsi86 driver shouldn't hand-roll its own bridge
connector. It should use the normal drm_bridge_connector. Let's switch
to do that, removing all of the custom code.

NOTE: this still _doesn't_ implement DRM_BRIDGE_ATTACH_NO_CONNECTOR
support for ti-sn65dsi86 and that would still be a useful thing to do
in the future. It was attempted in the past [1] but put on the back
burner. However, unless we instantly change ti-sn65dsi86 fully from
not supporting DRM_BRIDGE_ATTACH_NO_CONNECTOR at all to _only_
supporting DRM_BRIDGE_ATTACH_NO_CONNECTOR then we'll still need a bit
of time when we support both. This is a better way to support the old
way where the driver hand rolls things itself.

A new notes about the implementation here:
* When using the drm_bridge_connector the connector should be created
  after all the bridges, so we change the ordering a bit.
* I'm reasonably certain that we don't need to do anything to "free"
  the new drm_bridge_connector. If drm_bridge_connector_init() returns
  success then we know drm_connector_init() was called with the
  `drm_bridge_connector_funcs`. The `drm_bridge_connector_funcs` has a
  .destroy() that does all the cleanup. drm_connector_init() calls
  __drm_mode_object_add() with a drm_connector_free() that will call
  the .destroy().
* I'm also reasonably certain that I don't need to "undo" the
  drm_bridge_attach() if drm_bridge_connector_init() fails. The
  "detach" function is private and other similar code doesn't try to
  undo the drm_bridge_attach() in error cases. There's also a comment
  indicating the lack of balance at the top of drm_bridge_attach().

[1] https://lore.kernel.org/r/20210920225801.227211-4-robdclark@gmail.comSigned-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204161245.v2.1.I3ab26b7f197cc56c874246a43e57913e9c2c1028@changeid

Use the one provided by TTM instead.

v2: drop new_mem parameter as well
Signed-off-by: NChristian König <christian.koenig@amd.com>
Tested-by: NBas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214093439.2989-5-christian.koenig@amd.com

The length of EDID block can be longer than 256 bytes, so we should use
`int` instead of `u8` for the `edid_pos` variable.

Fixes: 8bdfc5da ("drm/bridge: anx7625: Add anx7625 MIPI DSI/DPI to DP")
Signed-off-by: NPin-Yen Lin <treapking@chromium.org>
Reviewed-by: NJernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: NRobert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220210103827.402436-1-treapking@chromium.org

This is provided by TTM now.

Also switch man->size to bytes instead of pages and fix the double
printing of size and usage in debugfs.

v2: fix size checking as well
Signed-off-by: NChristian König <christian.koenig@amd.com>
Tested-by: NBas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214093439.2989-8-christian.koenig@amd.com

This is provided by TTM now.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214093439.2989-7-christian.koenig@amd.com

This is provided by TTM now.

Also switch man->size to bytes instead of pages and fix the double
printing of size and usage in debugfs.

v2: fix size checking as well
Signed-off-by: NChristian König <christian.koenig@amd.com>
Tested-by: NBas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214093439.2989-6-christian.koenig@amd.com

platform_get_resource() may fail and return NULL, so check it's value
before using it.
Reported-by: NZou Wei <zou_wei@huawei.com>
Signed-off-by: NKevin Tang <kevin3.tang@gmail.com>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Acked-by: NThomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/all/20220117084156.9338-1-kevin3.tang@gmail.com

v1 -> v2:
- new patch

'drm' could be null in sprd_drm_shutdown, and drm_warn maybe dereference
it, remove this warning log.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NKevin Tang <kevin3.tang@gmail.com>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Acked-by: NThomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/all/20220117084044.9210-1-kevin3.tang@gmail.com

v1 -> v2:
- Split checking platform_get_resource() return value to a separate patch
- Use dev_warn() instead of removing the warning log

On commit 43531edd ("drm/sprd: add Unisoc's drm kms master"),
adds the config DRM_SPRD, which selects DRM_KMS_CMA_HELPER.

However, commit 09717af7 ("drm: Remove CONFIG_DRM_KMS_CMA_HELPER
option") just removed the DRM_KMS_CMA_HELPER.
So the select DRM_KMS_CMA_HELPER refers to a non-existing kconfig symbol.
Reported-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: NKevin Tang <kevin3.tang@gmail.com>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Acked-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NLukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/all/20220117083820.6893-2-kevin3.tang@gmail.com

v1 -> v2:
- fix commit comments long lines issue and drop "On linux-next" comments

It makes sense to have this in the common manager for debugging and
accounting of how much resources are used.

v2: cleanup kerneldoc a bit
v3: drop the atomic, update counter under lock instead
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com> (v1)
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Tested-by: NBas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214093439.2989-2-christian.koenig@amd.com

Leave the man->size units as driver defined.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214093439.2989-1-christian.koenig@amd.comReviewed-by: NMatthew Auld <matthew.auld@intel.com>

List panel under aux-bus node if it's connected to anx7625's aux bus.
Signed-off-by: NHsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NRobert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220213103437.3363848-4-hsinyi@chromium.org

Support reading edid through aux channel if panel is connected to aux
bus. Extend anx7625_aux_dpcd_trans() to implement aux transfer function:

1. panel is populated in devm_of_dp_aux_populate_ep_devices(), so move
   anx7625_parse_dt() after.
2. Use pm runtime autosuspend since aux transfer function is called
   multiple times when reading edid.
3. No-op if aux transfer length is 0.
Signed-off-by: NHsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: NXin Ji <xji@analogixsemi.com>
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NRobert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220213103437.3363848-3-hsinyi@chromium.org

Use devm_kzalloc instead of kzalloc and drop kfree(). Let the memory
handled by driver detach.
Signed-off-by: NHsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: NXin Ji <xji@analogixsemi.com>
Signed-off-by: NRobert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220213103437.3363848-2-hsinyi@chromium.org

Send DPCD command to downstream before anx7625 power down,
let downstream monitor enter into standby mode.
Signed-off-by: NXin Ji <xji@analogixsemi.com>
Signed-off-by: NHsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: NHsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: NRobert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220213103437.3363848-1-hsinyi@chromium.org

We have to make sure that
- JZ_LCD_OSDC_ALPHAEN is set
- plane f0 is disabled as it's not working yet

Tested on MIPS Creator CI20 board.
Signed-off-by: NPaul Boddie <paul@boddie.org.uk>
Signed-off-by: NEzequiel Garcia <ezequiel@collabora.com>
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Fixes: ef2f5d0a ("drm/ingenic: prepare ingenic drm for later addition of JZ4780")
Signed-off-by: NPaul Cercueil <paul@crapouillou.net>
[pcercuei: add proper fixes commit, slightly reword commit description]
Link: https://patchwork.freedesktop.org/patch/msgid/9d3a2000d2bb014f1afb0613537bdc523202135d.1644681054.git.hns@goldelico.com

Set the VM_DONTDUMP flag on mmap'ed VMAs to omit them from core
dumps. It's display-buffer memory; who knows what secrets these
buffers contain.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NChia-I Wu <olvaffe@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209155634.3994-3-tzimmermann@suse.de

Initialize default vm_ops in static initialization of the GEM SHMEM funcs,
instead of the mmap code. It's simply better style. GEM helpers will later
set a VMA's vm_ops from the default automatically.

v2:
	* also update the drivers that build upon GEM SHMEM
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NSteven Price <steven.price@arm.com>
Reviewed-by: NChia-I Wu <olvaffe@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209155634.3994-2-tzimmermann@suse.de

Add DT bindings for the hdmi driver for the Ingenic JZ4780 SoC.
Based on .txt binding from Zubair Lutfullah Kakakhel
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NH. Nikolaus Schaller <hns@goldelico.com>
Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NPaul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/c806c6007f7bb090bf96ff6bd827f03e88bf4712.1644675566.git.hns@goldelico.com

Currently when users try to run an application with lima and that hits
an issue such as a timeout, a message saying "fail to save task state"
and "error task list is full" is shown in dmesg.

The error task dump is a debug feature disabled by default, so the
error task list is usually not going to be available at all.
The message can be misleading and creates confusion in bug reports.

We can avoid that code path and that particular message when the user
has not explicitly set the max_error_tasks parameter to enable the
feature.
Signed-off-by: NErico Nunes <nunes.erico@gmail.com>
Reviewed-by: NQiang Yu <yuq825@gmail.com>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Signed-off-by: NQiang Yu <yuq825@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209093700.30901-1-nunes.erico@gmail.com

Update function name.
Signed-off-by: NAndrey Grodzovsky <andrey.grodzovsky@amd.com>
Reported-by: Nkernel test robot <lkp@intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220211205500.601391-1-andrey.grodzovsky@amd.com

The Bifrost GPU in Rockchip RK356x SoCs has a core and a bus clock.
Reflect this in the SoC specific part of the binding.
Signed-off-by: NAlex Bee <knaerzche@gmail.com>
[move the changes to the SoC section]
Signed-off-by: NMichael Riesch <michael.riesch@wolfvision.net>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209215549.94524-2-michael.riesch@wolfvision.net

The IDVS group size feature was missing. It is used on some Bifrost and
Valhall GPUs, and is the last kernel-relevant Bifrost feature we're
missing.

This feature adds an extra IDVS group size field to the JM_CONFIG
register. In kbase, the value is configurable via the device tree; kbase
uses 0xF as a default if no value is specified. Until we find a device
demanding otherwise, let's always set the 0xF default on devices which
support this feature mimicking kbase's behaviour.

Tuning this register slightly improves performance of index-driven
vertex shading. On Mali-G52 (with Mesa), overall glmark2 score is
improved from 1026 to 1037. Geometry-heavy scenes like -bshading are
improved from 1068 to 1098.
Signed-off-by: NAlyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: NSteven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220211145849.3148-1-alyssa.rosenzweig@collabora.com

It is illegal to add a dma_fence_chain as timeline point. Flatten out
the fences into a dma_fence_array instead.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NNirmoy Das <nirmoy.das@linux.intel.com>
Cc: <stable@vger.kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209182600.434803-1-christian.koenig@amd.com

When the dw-hdmi bridge is in first place of the bridge chain, this
means there is no way to select an input format of the dw-hdmi HW
component.

Since introduction of display-connector, negotiation was broken since
the dw-hdmi negotiation code only worked when the dw-hdmi bridge was
in last position of the bridge chain or behind another bridge also
supporting input & output format negotiation.

Commit 7cd70656 ("drm/bridge: display-connector: implement bus fmts callbacks")
was introduced to make negotiation work again by making display-connector
act as a pass-through concerning input & output format negotiation.

But in the case where the dw-hdmi is single in the bridge chain, for
example on Renesas SoCs, with the display-connector bridge the dw-hdmi
is no more single, breaking output format.
Reported-by: NBiju Das <biju.das.jz@bp.renesas.com>
Bisected-by: NKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Tested-by: NKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Fixes: 6c3c7199 ("drm/bridge: synopsys: dw-hdmi: add bus format negociation")
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
[narmstrong: add proper fixes commit]
Reviewed-by: NRobert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204143337.89221-1-narmstrong@baylibre.com

Clip the damage area horizontally if only a single scanline has been
changed. This is helpful to reduce the memcpy overhead for small writes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-6-tzimmermann@suse.de

Write helpers used to mark the complete screen as dirty. This is
wasteful for writes that only change a small portion of the screen.
Fix the problem by computing the damaged area from the written
memory range and perform damage handling accordingly.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-5-tzimmermann@suse.de

Add drm_fb_helper_memory_range_to_clip(), a helper function that
accepts an linear range of video memory and converts it into a
rectangle. The computed rectangle describes the damaged area in
terms of scanlines and pixels per scanline.

While at it, make the code more readable by using struct drm_rect
and related helpers.

The code was previously part of the deferred I/O helpers, but is
also useful for damage handling of regular write operations. Update
the deferred I/O code to use the new function.

v2:
	* rename helper (Javier)
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-4-tzimmermann@suse.de

Don't clip the damage rectangle against the viewport. This only
works if the viewport is located at the beginning of the video
memory and the video memory doesn't extend the screen (i.e., if
there's no overallocation).

Fbdev emulation transfers data from write operations into a
possible shadow buffer, then into a GEM buffer object, and finally
via graphics driver onto the screen.

If callers write outside the currently visible area, clipping the
damage rectangle against the viewport will loose these updates in
the shadow buffer and the fbdev's buffer object will contain stale
data. Panning the viewport to the stale area of the buffer will
display obsolete data.

Instead, mark all written areas as damaged, so that the damage
handler updates the buffer object from the shadow buffer for all
such areas. The graphics driver's later has the option of clipping
the damaged area against the viewport when updating the screen
from the buffer object.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-3-tzimmermann@suse.de

Computing the clip rectangle is prone to off-by-one errors when writes
happen near the end of a memory page. Point the end of the memory area
to the first trailing byte, so that (end - start) returns the area's
length.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-2-tzimmermann@suse.de