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.
Signed-off-by: Maxime Ripard maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_hdmi_regs.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi_regs.h b/drivers/gpu/drm/vc4/vc4_hdmi_regs.h index 19d2fdc446bc..99dde6e06a37 100644 --- 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 <linux/pm_runtime.h> + #include "vc4_hdmi.h"
#define VC4_HDMI_PACKET_STRIDE 0x24 @@ -412,6 +414,8 @@ 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)); + 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 vc4_hdmi *hdmi, 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);