linux-stable.git/include/drm, branch v6.1.136

drm/dp_mst: Fix drm RAD print

2025-04-10T12:33:32+00:00

[ Upstream commit 6bbce873a9c97cb12f5455c497be279ac58e707f ]

[Why]
The RAD of sideband message printed today is incorrect.
For RAD stored within MST branch
- If MST branch LCT is 1, it's RAD array is untouched and remained as 0.
- If MST branch LCT is larger than 1, use nibble to store the up facing
  port number in cascaded sequence as illustrated below:

  u8 RAD[0] = (LCT_2_UFP << 4) | LCT_3_UFP
     RAD[1] = (LCT_4_UFP << 4) | LCT_5_UFP
     ...

In drm_dp_mst_rad_to_str(), it wrongly to use BIT_MASK(4) to fetch the port
number of one nibble.

[How]
Adjust the code by:
- RAD array items are valuable only for LCT >= 1.
- Use 0xF as the mask to replace BIT_MASK(4)

V2:
- Document how RAD is constructed (Imre)

V3:
- Adjust the comment for rad[] so kdoc formats it properly (Lyude)

Fixes: 2f015ec6eab6 ("drm/dp_mst: Add sideband down request tracing + selftests")
Cc: Imre Deak 
Cc: Ville Syrjälä 
Cc: Harry Wentland 
Cc: Lyude Paul 
Reviewed-by: Lyude Paul 
Signed-off-by: Wayne Lin 
Signed-off-by: Lyude Paul 
Link: https://patchwork.freedesktop.org/patch/msgid/20250113091100.3314533-2-Wayne.Lin@amd.com
Signed-off-by: Sasha Levin

drm/ttm: Make sure the mapped tt pages are decrypted when needed

2024-12-14T18:54:54+00:00

commit 71ce046327cfd3aef3f93d1c44e091395eb03f8f upstream.

Some drivers require the mapped tt pages to be decrypted. In an ideal
world this would have been handled by the dma layer, but the TTM page
fault handling would have to be rewritten to able to do that.

A side-effect of the TTM page fault handling is using a dma allocation
per order (via ttm_pool_alloc_page) which makes it impossible to just
trivially use dma_mmap_attrs. As a result ttm has to be very careful
about trying to make its pgprot for the mapped tt pages match what
the dma layer thinks it is. At the ttm layer it's possible to
deduce the requirement to have tt pages decrypted by checking
whether coherent dma allocations have been requested and the system
is running with confidential computing technologies.

This approach isn't ideal but keeping TTM matching DMAs expectations
for the page properties is in general fragile, unfortunately proper
fix would require a rewrite of TTM's page fault handling.

Fixes vmwgfx with SEV enabled.

v2: Explicitly include cc_platform.h
v3: Use CC_ATTR_GUEST_MEM_ENCRYPT instead of CC_ATTR_MEM_ENCRYPT to
limit the scope to guests and log when memory decryption is enabled.

Signed-off-by: Zack Rusin 
Fixes: 3bf3710e3718 ("drm/ttm: Add a generic TTM memcpy move for page-based iomem")
Reviewed-by: Thomas Hellström 
Acked-by: Christian König 
Cc: Huang Rui 
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Cc:  # v5.14+
Link: https://patchwork.freedesktop.org/patch/msgid/20230926040359.3040017-1-zack@kde.org
Signed-off-by: Sasha Levin 
Signed-off-by: Ye Li 
Signed-off-by: Ajay Kaher 
Signed-off-by: Greg Kroah-Hartman

drm/dp_mst: Fix resetting msg rx state after topology removal

2024-12-14T18:54:35+00:00

commit a6fa67d26de385c3c7a23c1e109a0e23bfda4ec7 upstream.

If the MST topology is removed during the reception of an MST down reply
or MST up request sideband message, the
drm_dp_mst_topology_mgr::up_req_recv/down_rep_recv states could be reset
from one thread via drm_dp_mst_topology_mgr_set_mst(false), racing with
the reading/parsing of the message from another thread via
drm_dp_mst_handle_down_rep() or drm_dp_mst_handle_up_req(). The race is
possible since the reader/parser doesn't hold any lock while accessing
the reception state. This in turn can lead to a memory corruption in the
reader/parser as described by commit bd2fccac61b4 ("drm/dp_mst: Fix MST
sideband message body length check").

Fix the above by resetting the message reception state if needed before
reading/parsing a message. Another solution would be to hold the
drm_dp_mst_topology_mgr::lock for the whole duration of the message
reception/parsing in drm_dp_mst_handle_down_rep() and
drm_dp_mst_handle_up_req(), however this would require a bigger change.
Since the fix is also needed for stable, opting for the simpler solution
in this patch.

Cc: Lyude Paul 
Cc: 
Fixes: 1d082618bbf3 ("drm/display/dp_mst: Fix down/up message handling after sink disconnect")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13056
Reviewed-by: Lyude Paul 
Signed-off-by: Imre Deak 
Link: https://patchwork.freedesktop.org/patch/msgid/20241203160223.2926014-2-imre.deak@intel.com
Signed-off-by: Greg Kroah-Hartman

drm/printer: Allow NULL data in devcoredump printer

2024-10-17T13:21:46+00:00

[ Upstream commit 53369581dc0c68a5700ed51e1660f44c4b2bb524 ]

We want to determine the size of the devcoredump before writing it out.
To that end, we will run the devcoredump printer with NULL data to get
the size, alloc data based on the generated offset, then run the
devcorecump again with a valid data pointer to print.  This necessitates
not writing data to the data pointer on the initial pass, when it is
NULL.

v5:
 - Better commit message (Jonathan)
 - Add kerenl doc with examples (Jani)

Cc: Maarten Lankhorst 
Acked-by: Maarten Lankhorst 
Signed-off-by: Matthew Brost 
Reviewed-by: Jonathan Cavitt 
Link: https://patchwork.freedesktop.org/patch/msgid/20240801154118.2547543-3-matthew.brost@intel.com
Signed-off-by: Sasha Levin

drm/mipi-dsi: Fix theoretical int overflow in mipi_dsi_dcs_write_seq()

2024-08-03T06:49:10+00:00

[ Upstream commit 0b03829fdece47beba9ecb7dbcbde4585ee3663e ]

The mipi_dsi_dcs_write_seq() macro makes a call to
mipi_dsi_dcs_write_buffer() which returns a type ssize_t. The macro
then stores it in an int and checks to see if it's negative. This
could theoretically be a problem if "ssize_t" is larger than "int".

To see the issue, imagine that "ssize_t" is 32-bits and "int" is
16-bits, you could see a problem if there was some code out there that
looked like:

  mipi_dsi_dcs_write_seq(dsi, cmd, <32767 bytes as arguments>);

...since we'd get back that 32768 bytes were transferred and 32768
stored in a 16-bit int would look negative.

Though there are no callsites where we'd actually hit this (even if
"int" was only 16-bit), it's cleaner to make the types match so let's
fix it.

Fixes: 2a9e9daf7523 ("drm/mipi-dsi: Introduce mipi_dsi_dcs_write_seq macro")
Reviewed-by: Neil Armstrong 
Reviewed-by: Linus Walleij 
Signed-off-by: Douglas Anderson 
Link: https://lore.kernel.org/r/20240514102056.v5.1.I30fa4c8348ea316c886ef8a522a52fed617f930d@changeid
Signed-off-by: Neil Armstrong 
Link: https://patchwork.freedesktop.org/patch/msgid/20240514102056.v5.1.I30fa4c8348ea316c886ef8a522a52fed617f930d@changeid
Signed-off-by: Sasha Levin

drm/mipi-dsi: Fix mipi_dsi_dcs_write_seq() macro definition format

2024-08-03T06:49:10+00:00

[ Upstream commit 51d3c0e7dc3cf1dd91c34b0f9bdadda310c7ed5b ]

Change made using a `clang-format -i include/drm/drm_mipi_dsi.h` command.

Suggested-by: Sam Ravnborg 
Signed-off-by: Javier Martinez Canillas 
Reviewed-by: Sam Ravnborg 
Link: https://patchwork.freedesktop.org/patch/msgid/20230102202542.3494677-1-javierm@redhat.com
Stable-dep-of: 0b03829fdece ("drm/mipi-dsi: Fix theoretical int overflow in mipi_dsi_dcs_write_seq()")
Signed-off-by: Sasha Levin

drm/mipi-dsi: use correct return type for the DSC functions

2024-06-12T09:03:27+00:00

[ Upstream commit de1c705c50326acaceaf1f02bc5bf6f267c572bd ]

The functions mipi_dsi_compression_mode() and
mipi_dsi_picture_parameter_set() return 0-or-error rather than a buffer
size. Follow example of other similar MIPI DSI functions and use int
return type instead of size_t.

Fixes: f4dea1aaa9a1 ("drm/dsi: add helpers for DSI compression mode and PPS packets")
Reviewed-by: Marijn Suijten 
Reviewed-by: Jessica Zhang 
Signed-off-by: Dmitry Baryshkov 
Link: https://patchwork.freedesktop.org/patch/msgid/20240408-lg-sw43408-panel-v5-2-4e092da22991@linaro.org
Signed-off-by: Sasha Levin

drm/dp: Don't attempt AUX transfers when eDP panels are not powered

2024-06-12T09:03:21+00:00

[ Upstream commit 8df1ddb5bf11ab820ad991e164dab82c0960add9 ]

If an eDP panel is not powered on then any attempts to talk to it over
the DP AUX channel will timeout. Unfortunately these attempts may be
quite slow. Userspace can initiate these attempts either via a
/dev/drm_dp_auxN device or via the created i2c device.

Making the DP AUX drivers timeout faster is a difficult proposition.
In theory we could just poll the panel's HPD line in the AUX transfer
function and immediately return an error there. However, this is
easier said than done. For one thing, there's no hard requirement to
hook the HPD line up for eDP panels and it's OK to just delay a fixed
amount. For another thing, the HPD line may not be fast to probe. On
parade-ps8640 we need to wait for the bridge chip's firmware to boot
before we can get the HPD line and this is a slow process.

The fact that the transfers are taking so long to timeout is causing
real problems. The open source fwupd daemon sometimes scans DP busses
looking for devices whose firmware need updating. If it happens to
scan while a panel is turned off this scan can take a long time. The
fwupd daemon could try to be smarter and only scan when eDP panels are
turned on, but we can also improve the behavior in the kernel.

Let's let eDP panels drivers specify that a panel is turned off and
then modify the common AUX transfer code not to attempt a transfer in
this case.

Tested-by: Steev Klimaszewski 
Reviewed-by: Hsin-Yi Wang 
Tested-by: Eizan Miyamoto 
Acked-by: Neil Armstrong 
Signed-off-by: Douglas Anderson 
Link: https://patchwork.freedesktop.org/patch/msgid/20240202141109.1.I24277520ac754ea538c9b14578edc94e1df11b48@changeid
Stable-dep-of: 5e842d55bad7 ("drm/panel: atna33xc20: Fix unbalanced regulator in the case HPD doesn't assert")
Signed-off-by: Sasha Levin

drm/probe-helper: warn about negative .get_modes()

2024-04-03T13:19:36+00:00

[ Upstream commit 7af03e688792293ba33149fb8df619a8dff90e80 ]

The .get_modes() callback is supposed to return the number of modes,
never a negative error code. If a negative value is returned, it'll just
be interpreted as a negative count, and added to previous calculations.

Document the rules, but handle the negative values gracefully with an
error message.

Cc: stable@vger.kernel.org
Acked-by: Thomas Zimmermann 
Link: https://patchwork.freedesktop.org/patch/msgid/50208c866facc33226a3c77b82bb96aeef8ef310.1709913674.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula 
Signed-off-by: Sasha Levin

drm: Fix drm_fixp2int_round() making it add 0.5

2024-03-26T22:21:00+00:00

[ Upstream commit 807f96abdf14c80f534c78f2d854c2590963345c ]

As well noted by Pekka[1], the rounding of drm_fixp2int_round is wrong.
To round a number, you need to add 0.5 to the number and floor that,
drm_fixp2int_round() is adding 0.0000076. Make it add 0.5.

[1]: https://lore.kernel.org/all/20240301135327.22efe0dd.pekka.paalanen@collabora.com/

Fixes: 8b25320887d7 ("drm: Add fixed-point helper to get rounded integer values")
Suggested-by: Pekka Paalanen 
Reviewed-by: Harry Wentland 
Reviewed-by: Melissa Wen 
Signed-off-by: Arthur Grillo 
Signed-off-by: Melissa Wen 
Link: https://patchwork.freedesktop.org/patch/msgid/20240316-drm_fixed-v2-1-c1bc2665b5ed@riseup.net
Signed-off-by: Sasha Levin