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    SubjectRe: [PATCH 2/6] drm/rockchip: vop: fix iommu page fault when resume
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    Hi mark,

    在 2017/7/31 17:49, Mark Yao 写道:
    > Iommu would get page fault with following path:
    > vop_disable:
    > 1, disable all windows and set vop config done
    > 2, vop enter to standy, all windows not works, but their registers
    > are not clean, when you read window's enable bit, may found the
    > window is enable.
    >
    > vop_enable:
    > 1, memcpy(vop->regsbak, vop->regs, len)
    > save current vop registers to vop->regsbak, then you can found
    > window is enable on regsbak.
    > 2, VOP_WIN_SET(vop, win, gate, 1);
    > force enable window gate, but gate and enable are on same
    > hardware register, then window enable bit rewrite to vop hardware.
    > 3, vop power on, and vop might try to scan destroyed buffer,
    > then iommu get page fault.
    >
    > Move windows disable after vop regsbak restore, then vop regsbak mechanism
    > would keep tracing the modify, everything would be safe.
    >
    > Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
    > ---
    > drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 33 +++++++++++++----------------
    > 1 file changed, 15 insertions(+), 18 deletions(-)
    >

    Reviewed-by: Sandy huang <sandy.huang@rock-chips.com>

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