[PATCH v4 13/15] drm/amd/display: Use ARCH_HAS_KERNEL_FPU_SUPPORT

Thiago Jung Bauermann thiago.bauermann at linaro.org
Wed Apr 10 18:02:09 PDT 2024


Hello Samuel,

Thank you for the quick reply!

Samuel Holland <samuel.holland at sifive.com> writes:
> On 2024-04-10 5:21 PM, Thiago Jung Bauermann wrote:
>>
>> Unfortunately this patch causes build failures on arm with allyesconfig
>> and allmodconfig. Tested with next-20240410.

<snip>

> In both cases, the issue is that the toolchain requires runtime support to
> convert between `unsigned long long` and `double`, even when hardware FP is
> enabled. There was some past discussion about GCC inlining some of these
> conversions[1], but that did not get implemented.

Thank you for the explanation and the bugzilla reference. I added a
comment there mentioning that the problem came up again with this patch
series.

> The short-term fix would be to drop the `select ARCH_HAS_KERNEL_FPU_SUPPORT` for
> 32-bit arm until we can provide these runtime library functions.

Does this mean that patch 2 in this series:

[PATCH v4 02/15] ARM: Implement ARCH_HAS_KERNEL_FPU_SUPPORT

will be dropped?

--
Thiago



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