From ac9098b1794bc4db463241db7ed090a11dcaa541 Mon Sep 17 00:00:00 2001 From: Akhil P Oommen Date: Mon, 8 Sep 2025 13:56:59 +0530 Subject: [PATCH] drm/msm: Add an ftrace for gpu register access With IFPC, there is a probability of accessing a GX domain register when it is collapsed, which leads to gmu fence errors. To debug this, we need to trace every gpu register accesses and identify the one just before a gmu fence error. So, add an ftrace to track all gpu register accesses. Signed-off-by: Akhil P Oommen Patchwork: https://patchwork.freedesktop.org/patch/673366/ Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/msm_gpu.h | 8 ++++++++ drivers/gpu/drm/msm/msm_gpu_trace.h | 12 ++++++++++++ 2 files changed, 20 insertions(+) diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h index b2a96544f92a5..866bb090af064 100644 --- a/drivers/gpu/drm/msm/msm_gpu.h +++ b/drivers/gpu/drm/msm/msm_gpu.h @@ -16,6 +16,7 @@ #include "msm_drv.h" #include "msm_fence.h" +#include "msm_gpu_trace.h" #include "msm_ringbuffer.h" #include "msm_gem.h" @@ -613,16 +614,19 @@ struct msm_gpu_state { static inline void gpu_write(struct msm_gpu *gpu, u32 reg, u32 data) { + trace_msm_gpu_regaccess(reg); writel(data, gpu->mmio + (reg << 2)); } static inline u32 gpu_read(struct msm_gpu *gpu, u32 reg) { + trace_msm_gpu_regaccess(reg); return readl(gpu->mmio + (reg << 2)); } static inline void gpu_rmw(struct msm_gpu *gpu, u32 reg, u32 mask, u32 or) { + trace_msm_gpu_regaccess(reg); msm_rmw(gpu->mmio + (reg << 2), mask, or); } @@ -644,7 +648,9 @@ static inline u64 gpu_read64(struct msm_gpu *gpu, u32 reg) * when the lo is read, so make sure to read the lo first to trigger * that */ + trace_msm_gpu_regaccess(reg); val = (u64) readl(gpu->mmio + (reg << 2)); + trace_msm_gpu_regaccess(reg+1); val |= ((u64) readl(gpu->mmio + ((reg + 1) << 2)) << 32); return val; @@ -652,8 +658,10 @@ static inline u64 gpu_read64(struct msm_gpu *gpu, u32 reg) static inline void gpu_write64(struct msm_gpu *gpu, u32 reg, u64 val) { + trace_msm_gpu_regaccess(reg); /* Why not a writeq here? Read the screed above */ writel(lower_32_bits(val), gpu->mmio + (reg << 2)); + trace_msm_gpu_regaccess(reg+1); writel(upper_32_bits(val), gpu->mmio + ((reg + 1) << 2)); } diff --git a/drivers/gpu/drm/msm/msm_gpu_trace.h b/drivers/gpu/drm/msm/msm_gpu_trace.h index 781bbe5540bde..5417f8d389a37 100644 --- a/drivers/gpu/drm/msm/msm_gpu_trace.h +++ b/drivers/gpu/drm/msm/msm_gpu_trace.h @@ -219,6 +219,18 @@ TRACE_EVENT(msm_mmu_prealloc_cleanup, TP_printk("count=%u, remaining=%u", __entry->count, __entry->remaining) ); +TRACE_EVENT(msm_gpu_regaccess, + TP_PROTO(u32 offset), + TP_ARGS(offset), + TP_STRUCT__entry( + __field(u32, offset) + ), + TP_fast_assign( + __entry->offset = offset; + ), + TP_printk("offset=0x%x", __entry->offset) +); + #endif #undef TRACE_INCLUDE_PATH -- 2.47.3