• Konrad Dybcio's avatar
    drm/msm/adreno: adreno_gpu: Use suspend() instead of idle() on load error · 3eeca5e5
    Konrad Dybcio authored
    The adreno_load_gpu() path is guarded by an error check on
    adreno_load_fw(). This function is responsible for loading
    Qualcomm-only-signed binaries (e.g. SQE and GMU FW for A6XX), but it
    does not take the vendor-signed ZAP blob into account.
    
    By embedding the SQE (and GMU, if necessary) firmware into the
    initrd/kernel, we can trigger and unfortunate path that would not bail
    out early and proceed with gpu->hw_init(). That will fail, as the ZAP
    loader path will not find the firmware and return back to
    adreno_load_gpu().
    
    This error path involves pm_runtime_put_sync() which then calls idle()
    instead of suspend(). This is suboptimal, as it means that we're not
    going through the clean shutdown sequence. With at least A619_holi, this
    makes the GPU not wake up until it goes through at least one more
    start-fail-stop cycle. The pm_runtime_put_sync that appears in the error
    path actually does not guarantee that because of the earlier enabling of
    runtime autosuspend.
    
    Fix that by using pm_runtime_put_sync_suspend to force a clean shutdown.
    
    Test cases:
    1. All firmware baked into kernel
    2. error loading ZAP fw in initrd -> load from rootfs at DE start
    
    Both succeed on A619_holi (SM6375) and A630 (SDM845).
    
    Fixes: 0d997f95 ("drm/msm/adreno: fix runtime PM imbalance at gpu load")
    Signed-off-by: default avatarKonrad Dybcio <konrad.dybcio@linaro.org>
    Reviewed-by: default avatarJohan Hovold <johan+linaro@kernel.org>
    Patchwork: https://patchwork.freedesktop.org/patch/530001/
    Link: https://lore.kernel.org/r/20230330231517.2747024-1-konrad.dybcio@linaro.orgSigned-off-by: default avatarRob Clark <robdclark@chromium.org>
    3eeca5e5
adreno_device.c 17.9 KB