drm/i915: fix freeze with blank screen booting highmem
x86_64 boots and displays fine, but booting x86_32 with CONFIG_HIGHMEM has frozen with a blank screen throughout 3.16-rc on this ThinkPad T420s, with i915 generation 6 graphics. Fix 9d0a6fa6 ("drm/i915: add render state initialization"): kunmap() takes struct page * argument, not virtual address. Which the compiler kindly points out, if you use the appropriate u32 *batch, instead of silencing it with a void *. Why did bisection lead decisively to nearby 229b0489 ("drm/i915: add null render states for gen6, gen7 and gen8")? Because the u32 deposited at that virtual address by the previous stub failed the PageHighMem test, and so did no harm. Signed-off-by:Hugh Dickins <hughd@google.com> Signed-off-by:
Daniel Vetter <daniel.vetter@ffwll.ch>
parent
a0d036b0
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