<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/gpu/drm/amd/display/dc/basics, branch master</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>drm/amd/display: adjust floating point format for gamut remap when needed</title>
<updated>2026-07-28T23:17:31+00:00</updated>
<author>
<name>Clay King</name>
<email>clayking@amd.com</email>
</author>
<published>2026-07-15T21:41:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1c5e6cd8291f3e3c9f27b592a11bdb8408b2c64f'/>
<id>1c5e6cd8291f3e3c9f27b592a11bdb8408b2c64f</id>
<content type='text'>
[Why]
The MPCCs different gamut remap matrices allow for S2D13 and S3D12 floating
point formats, but only S2D13 is used. There may be cases where more
integer bits are required.

[How]
Switch to S3D12 if any entries in the remap matrix cannot fit in S2D13.
Otherwise, prefer the extra precision of S2D13. Communicate the max value
that hw can support to dm via dc color caps.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Signed-off-by: Clay King &lt;clayking@amd.com&gt;
Signed-off-by: Fangzhi Zuo &lt;jerry.zuo@amd.com&gt;
Tested-by: Dan Wheeler &lt;daniel.wheeler@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[Why]
The MPCCs different gamut remap matrices allow for S2D13 and S3D12 floating
point formats, but only S2D13 is used. There may be cases where more
integer bits are required.

[How]
Switch to S3D12 if any entries in the remap matrix cannot fit in S2D13.
Otherwise, prefer the extra precision of S2D13. Communicate the max value
that hw can support to dm via dc color caps.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Signed-off-by: Clay King &lt;clayking@amd.com&gt;
Signed-off-by: Fangzhi Zuo &lt;jerry.zuo@amd.com&gt;
Tested-by: Dan Wheeler &lt;daniel.wheeler@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amd/display: Use krealloc_array() in dal_vector_reserve()</title>
<updated>2026-06-03T17:35:57+00:00</updated>
<author>
<name>Harry Wentland</name>
<email>harry.wentland@amd.com</email>
</author>
<published>2026-05-05T15:52:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=37668568641ccc4cc1dbca4923d0a16609dd5707'/>
<id>37668568641ccc4cc1dbca4923d0a16609dd5707</id>
<content type='text'>
[Why &amp; How]
dal_vector_reserve() computes the allocation size as
"capacity * vector-&gt;struct_size" using uint32_t arithmetic, which can
silently wrap to a small value on overflow. This would cause krealloc to
return a smaller buffer than expected, leading to heap overflows on
subsequent vector appends.

Replace krealloc() with krealloc_array() which performs an internal
overflow check and returns NULL on wrap, preventing the issue.

Fixes: 2004f45ef83f ("drm/amd/display: Use kernel alloc/free")
Assisted-by: Copilot:claude-opus-4.6
Reviewed-by: Alex Hung &lt;alex.hung@amd.com&gt;
Signed-off-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Signed-off-by: Ray Wu &lt;ray.wu@amd.com&gt;
Tested-by: Daniel Wheeler &lt;daniel.wheeler@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[Why &amp; How]
dal_vector_reserve() computes the allocation size as
"capacity * vector-&gt;struct_size" using uint32_t arithmetic, which can
silently wrap to a small value on overflow. This would cause krealloc to
return a smaller buffer than expected, leading to heap overflows on
subsequent vector appends.

Replace krealloc() with krealloc_array() which performs an internal
overflow check and returns NULL on wrap, preventing the issue.

Fixes: 2004f45ef83f ("drm/amd/display: Use kernel alloc/free")
Assisted-by: Copilot:claude-opus-4.6
Reviewed-by: Alex Hung &lt;alex.hung@amd.com&gt;
Signed-off-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Signed-off-by: Ray Wu &lt;ray.wu@amd.com&gt;
Tested-by: Daniel Wheeler &lt;daniel.wheeler@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amd/display: Fix type mismatches using guards and explicit casts</title>
<updated>2026-05-05T13:56:52+00:00</updated>
<author>
<name>Gaghik Khachatrian</name>
<email>gaghik.khachatrian@amd.com</email>
</author>
<published>2026-04-21T16:24:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=64b4c4cdfddd31d3a0ec468afccb7ff7cd926682'/>
<id>64b4c4cdfddd31d3a0ec468afccb7ff7cd926682</id>
<content type='text'>
[Why]
Address signed/unsigned comparison warnings across dc paths to keep
builds warning-clean and improve type safety at comparison boundaries.
Most warnings came from signed loop/index temporaries compared against
unsigned counters and table sizes, plus a smaller number of mixed
signed/unsigned clock, bandwidth, and geometry comparisons.

[How]
Aligned iterator and temporary variable types with the semantic type
of the compared bounds. Used unsigned indices for loops bounded by unsigned
counters and table sizes, while retaining signed types where values are
semantically signed or participate in arithmetic that may legitimately go
negative. Where mixed signed/unsigned comparisons are intentional, applied
explicit boundary casts or guarded comparisons instead of broad type
changes.

No functional behavior changes are intended; this is a warning-resolution
and type-alignment cleanup.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Signed-off-by: Gaghik Khachatrian &lt;gaghik.khachatrian@amd.com&gt;
Signed-off-by: James Lin &lt;pinglei.lin@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[Why]
Address signed/unsigned comparison warnings across dc paths to keep
builds warning-clean and improve type safety at comparison boundaries.
Most warnings came from signed loop/index temporaries compared against
unsigned counters and table sizes, plus a smaller number of mixed
signed/unsigned clock, bandwidth, and geometry comparisons.

[How]
Aligned iterator and temporary variable types with the semantic type
of the compared bounds. Used unsigned indices for loops bounded by unsigned
counters and table sizes, while retaining signed types where values are
semantically signed or participate in arithmetic that may legitimately go
negative. Where mixed signed/unsigned comparisons are intentional, applied
explicit boundary casts or guarded comparisons instead of broad type
changes.

No functional behavior changes are intended; this is a warning-resolution
and type-alignment cleanup.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Signed-off-by: Gaghik Khachatrian &lt;gaghik.khachatrian@amd.com&gt;
Signed-off-by: James Lin &lt;pinglei.lin@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amd/display: Fix implicit narrowing conversion warnings</title>
<updated>2026-04-17T19:41:15+00:00</updated>
<author>
<name>Gaghik Khachatrian</name>
<email>gaghik.khachatrian@amd.com</email>
</author>
<published>2026-03-31T23:14:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f4cdbb5d54057838b14a9b537309df24f20232c2'/>
<id>f4cdbb5d54057838b14a9b537309df24f20232c2</id>
<content type='text'>
[Why]
Multiple display source files contain implicit narrowing
conversions when assigning wider integer types (int, uint32_t)
to narrower fields (uint8_t, uint16_t) at hardware register,
protocol, and storage boundaries. These conversions are
intentional but undocumented, and accompanying runtime assertions
add noise without providing compile-time safety.

[How]
Add explicit casts at all intentional narrowing boundaries across
display source files. Use narrower loop variable types where loop
bounds guarantee safe range. Remove runtime assertions paired
with narrowing casts, inline single-use intermediate variables,
and revert block scopes and braces introduced solely to contain
those assertions.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Signed-off-by: Gaghik Khachatrian &lt;gaghik.khachatrian@amd.com&gt;
Signed-off-by: Chenyu Chen &lt;chen-yu.chen@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[Why]
Multiple display source files contain implicit narrowing
conversions when assigning wider integer types (int, uint32_t)
to narrower fields (uint8_t, uint16_t) at hardware register,
protocol, and storage boundaries. These conversions are
intentional but undocumented, and accompanying runtime assertions
add noise without providing compile-time safety.

[How]
Add explicit casts at all intentional narrowing boundaries across
display source files. Use narrower loop variable types where loop
bounds guarantee safe range. Remove runtime assertions paired
with narrowing casts, inline single-use intermediate variables,
and revert block scopes and braces introduced solely to contain
those assertions.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Signed-off-by: Gaghik Khachatrian &lt;gaghik.khachatrian@amd.com&gt;
Signed-off-by: Chenyu Chen &lt;chen-yu.chen@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amd/display: Fixed Silence complier warnings in dc</title>
<updated>2026-03-30T19:12:15+00:00</updated>
<author>
<name>Gaghik Khachatrian</name>
<email>gaghik.khachatrian@amd.com</email>
</author>
<published>2026-03-09T21:18:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f82480fafedf622541276d48a3b4fed20ce5d866'/>
<id>f82480fafedf622541276d48a3b4fed20ce5d866</id>
<content type='text'>
[Why]
Resolve compiler warnings by marking unused parameters explicitly.

[How]
In .c and .h function definitions, keep parameter names
in signatures and add a line with `(void)param;` in function body

Preserved function signatures and avoids breaking code paths that
may reference the parameter under conditional compilation.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Reviewed-by: Austin Zheng &lt;austin.zheng@amd.com&gt;
Signed-off-by: Gaghik Khachatrian &lt;gaghik.khachatrian@amd.com&gt;
Signed-off-by: Chuanyu Tseng &lt;chuanyu.tseng@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[Why]
Resolve compiler warnings by marking unused parameters explicitly.

[How]
In .c and .h function definitions, keep parameter names
in signatures and add a line with `(void)param;` in function body

Preserved function signatures and avoids breaking code paths that
may reference the parameter under conditional compilation.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Reviewed-by: Austin Zheng &lt;austin.zheng@amd.com&gt;
Signed-off-by: Gaghik Khachatrian &lt;gaghik.khachatrian@amd.com&gt;
Signed-off-by: Chuanyu Tseng &lt;chuanyu.tseng@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amd/display: Fix Silence signed/unsighed mismatch warning in dc</title>
<updated>2026-03-30T18:55:17+00:00</updated>
<author>
<name>Gaghik Khachatrian</name>
<email>gaghik.khachatrian@amd.com</email>
</author>
<published>2026-03-12T19:42:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=26ebcac0566b78a9e6bfb71fb6b3436e0fe251a6'/>
<id>26ebcac0566b78a9e6bfb71fb6b3436e0fe251a6</id>
<content type='text'>
[Why]
Implicit signed-to-unsigned conversions caused compiler
warnings in DC paths.

[How]
Added explicit (unsigned int)/(uint32_t) casts for sentinel -1
assignments and IRQ ~MASK initializers, with small cast alignment
in logging/DPCD code.

Functionality and behavior is unchanged; only type intent is explicit.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Signed-off-by: Gaghik Khachatrian &lt;gaghik.khachatrian@amd.com&gt;
Signed-off-by: Chuanyu Tseng &lt;chuanyu.tseng@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[Why]
Implicit signed-to-unsigned conversions caused compiler
warnings in DC paths.

[How]
Added explicit (unsigned int)/(uint32_t) casts for sentinel -1
assignments and IRQ ~MASK initializers, with small cast alignment
in logging/DPCD code.

Functionality and behavior is unchanged; only type intent is explicit.

Reviewed-by: Dillon Varone &lt;dillon.varone@amd.com&gt;
Signed-off-by: Gaghik Khachatrian &lt;gaghik.khachatrian@amd.com&gt;
Signed-off-by: Chuanyu Tseng &lt;chuanyu.tseng@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Convert more 'alloc_obj' cases to default GFP_KERNEL arguments</title>
<updated>2026-02-22T04:03:00+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-22T04:03:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=32a92f8c89326985e05dce8b22d3f0aa07a3e1bd'/>
<id>32a92f8c89326985e05dce8b22d3f0aa07a3e1bd</id>
<content type='text'>
This converts some of the visually simpler cases that have been split
over multiple lines.  I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.

Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script.  I probably had made it a bit _too_ trivial.

So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.

The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This converts some of the visually simpler cases that have been split
over multiple lines.  I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.

Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script.  I probably had made it a bit _too_ trivial.

So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.

The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Convert 'alloc_obj' family to use the new default GFP_KERNEL argument</title>
<updated>2026-02-22T01:09:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-22T00:37:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43'/>
<id>bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43</id>
<content type='text'>
This was done entirely with mindless brute force, using

    git grep -l '\&lt;k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This was done entirely with mindless brute force, using

    git grep -l '\&lt;k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Replace kmalloc with kmalloc_obj for non-scalar types</title>
<updated>2026-02-21T09:02:28+00:00</updated>
<author>
<name>Kees Cook</name>
<email>kees@kernel.org</email>
</author>
<published>2026-02-21T07:49:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=69050f8d6d075dc01af7a5f2f550a8067510366f'/>
<id>69050f8d6d075dc01af7a5f2f550a8067510366f</id>
<content type='text'>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amd/display: Multiplication result converted to larger type</title>
<updated>2025-08-27T17:57:50+00:00</updated>
<author>
<name>Clay King</name>
<email>clayking@amd.com</email>
</author>
<published>2025-08-14T20:58:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9ec77e3a4b8913508bfd10891ce339af05e671ef'/>
<id>9ec77e3a4b8913508bfd10891ce339af05e671ef</id>
<content type='text'>
Consolidating multiple CodeQL Fixes for alerts with rule id: cpp/integer-multiplication-cast-to-long

Reviewed-by: Joshua Aberback &lt;joshua.aberback@amd.com&gt;
Signed-off-by: Clay King &lt;clayking@amd.com&gt;
Signed-off-by: Aurabindo Pillai &lt;aurabindo.pillai@amd.com&gt;
Tested-by: Dan Wheeler &lt;daniel.wheeler@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Consolidating multiple CodeQL Fixes for alerts with rule id: cpp/integer-multiplication-cast-to-long

Reviewed-by: Joshua Aberback &lt;joshua.aberback@amd.com&gt;
Signed-off-by: Clay King &lt;clayking@amd.com&gt;
Signed-off-by: Aurabindo Pillai &lt;aurabindo.pillai@amd.com&gt;
Tested-by: Dan Wheeler &lt;daniel.wheeler@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
