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    Subject[PATCH 5.19 0419/1157] drm/vc4: hdmi: Switch to pm_runtime_status_suspended
    Date
    From: Dave Stevenson <dave.stevenson@raspberrypi.com>

    [ Upstream commit fcef97e70094a33ded73b3eb9bef06698c6e9c12 ]

    If the controller isn't clocked or its domain powered up, the register
    accesses will either stall the CPU or return garbage, respectively.

    Thus, we had a warning in our register access function to complain when
    that kind of risky accesses were performed.

    In order to check the runtime_pm power state, we were using
    pm_runtime_active(), but it turns out that it will become active only
    once the runtime_resume hook has been executed.

    This prevents us from doing any WARN-free register access in our
    runtime_resume() implementation, while this is valid.

    Let's switch to pm_runtime_status_suspended() instead.

    Fixes: 14e193b95604 ("drm/vc4: hdmi: Warn if we access the controller while disabled")
    Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
    Link: https://lore.kernel.org/r/20220613144800.326124-23-maxime@cerno.tech
    Signed-off-by: Maxime Ripard <maxime@cerno.tech>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/gpu/drm/vc4/vc4_hdmi_regs.h | 4 ++--
    1 file changed, 2 insertions(+), 2 deletions(-)

    diff --git a/drivers/gpu/drm/vc4/vc4_hdmi_regs.h b/drivers/gpu/drm/vc4/vc4_hdmi_regs.h
    index 549cc63dab39..0198de96c7b2 100644
    --- a/drivers/gpu/drm/vc4/vc4_hdmi_regs.h
    +++ b/drivers/gpu/drm/vc4/vc4_hdmi_regs.h
    @@ -423,7 +423,7 @@ static inline u32 vc4_hdmi_read(struct vc4_hdmi *hdmi,
    const struct vc4_hdmi_variant *variant = hdmi->variant;
    void __iomem *base;

    - WARN_ON(!pm_runtime_active(&hdmi->pdev->dev));
    + WARN_ON(pm_runtime_status_suspended(&hdmi->pdev->dev));

    if (reg >= variant->num_registers) {
    dev_warn(&hdmi->pdev->dev,
    @@ -453,7 +453,7 @@ static inline void vc4_hdmi_write(struct vc4_hdmi *hdmi,

    lockdep_assert_held(&hdmi->hw_lock);

    - WARN_ON(!pm_runtime_active(&hdmi->pdev->dev));
    + WARN_ON(pm_runtime_status_suspended(&hdmi->pdev->dev));

    if (reg >= variant->num_registers) {
    dev_warn(&hdmi->pdev->dev,
    --
    2.35.1


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