GPU_PRFCNT_SHADER_EN
gpu_write(pfdev, GPU_PRFCNT_SHADER_EN, 0xffffffff);
gpu_write(pfdev, GPU_PRFCNT_SHADER_EN, 0x0);
gpu_write(pfdev, GPU_PRFCNT_SHADER_EN, 0);
gpu_write(pfdev, GPU_PRFCNT_SHADER_EN, 0);