From d0a44f399526a061e74b9a34b554f3d0e9cdddb3 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Thu, 19 Aug 2021 15:59:31 +0200 Subject: [PATCH] drm/vc4: hdmi: Warn if we access the controller while disabled We've had many silent hangs where the kernel would look like it just stalled due to the access to one of the HDMI registers while the controller was disabled. Add a warning if we're about to do that so that it's at least not silent anymore. Reviewed-by: Dave Stevenson Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20210819135931.895976-7-maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_hdmi_regs.h | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/gpu/drm/vc4/vc4_hdmi_regs.h +++ b/drivers/gpu/drm/vc4/vc4_hdmi_regs.h @@ -1,6 +1,8 @@ #ifndef _VC4_HDMI_REGS_H_ #define _VC4_HDMI_REGS_H_ +#include + #include "vc4_hdmi.h" #define VC4_HDMI_PACKET_STRIDE 0x24 @@ -412,6 +414,8 @@ static inline u32 vc4_hdmi_read(struct v const struct vc4_hdmi_variant *variant = hdmi->variant; void __iomem *base; + WARN_ON(!pm_runtime_active(&hdmi->pdev->dev)); + if (reg >= variant->num_registers) { dev_warn(&hdmi->pdev->dev, "Invalid register ID %u\n", reg); @@ -438,6 +442,8 @@ static inline void vc4_hdmi_write(struct const struct vc4_hdmi_variant *variant = hdmi->variant; void __iomem *base; + WARN_ON(!pm_runtime_active(&hdmi->pdev->dev)); + if (reg >= variant->num_registers) { dev_warn(&hdmi->pdev->dev, "Invalid register ID %u\n", reg);