# DF-2085 — agp_sis_set_aperture operator precedence error

## Verdict
REPRODUCED (source-only confirmation). Bug confirmed by source tracing.

## Mechanism
agp_sis_set_aperture() (agp_sis.c:215): gws=ffs(aperture / 4*1024*1024)-1. / and * share precedence left-to-right, so this evaluates as ((aperture/4)*1024)*1024 which overflows u32 for valid apertures (4MB..256MB) instead of aperture/(4*1024*1024). Wrong GWS value written to AGP_SIS_WINCTRL.

## Fix
Add parentheses: gws = ffs(aperture / (4*1024*1024)) - 1.

## Batch-build status
Applied with all 24 other fixes; kernel + modules compiled **rc=0, 0 errors, -Werror**.