drm/nouveau/dispnv50: program pixel clocks above 2.147GHz on GB20x

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The HEAD_SET_PIXEL_CLOCK_FREQUENCY(_MAX) methods carry only 31 HERTZ
bits. Starting with C97D the upper bits live in separate
HEAD_SET_PIXEL_CLOCK_FREQUENCY_HI(_MAX) methods, which nouveau never
programmed and headca7d_mode() computed m->clock * 1000 into the 31-bit
field. NVVAL's mask then silently truncates anything past 2^31 Hz, which
means that every mode scanned out at pclk modulo 2^31.

No mode nouveau can currently commit crosses the boundary (an
uncompressed HDMI FRL mode tops out around 1.78GHz at 8bpc), but this is
a prerequisite for the upcoming DSC work, which makes 2.147GHz+ modes
reachable.

Program the full value split across the low and HI methods, exactly
as OpenRM's EvoSetRasterParams9() does (nvkms-evo4.c, 31-bit low word
plus the 4 HI HERTZ bits, giving 35 bits of range).

Signed-off-by: Mohamed Ahmed <mohamedahmedegypt2001@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patch.msgid.link/20260825001408.14219-10-mohamedahmedegypt2001@gmail.com

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Mohamed Ahmed 2026-08-25 04:14:07 +04:00 • committed by Lyude Paul

parent 2d354adc5b

commit 1ec57bb049

2 changed files with 22 additions and 3 deletions

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21

drivers/gpu/drm/nouveau/dispnv50/headca7d.c

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4

drivers/gpu/drm/nouveau/include/nvhw/class/clca7d.h

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