On Mon, Aug 27, 2018 at 12:47:19PM +0530, Sharat Masetty wrote:
> The devfreq framework requires the drivers to provide busy time estimations.
> The GPU driver relies on the hardware performance counteres for the busy time
> estimations, but different hardware revisions have counters which can be
> sourced from different clocks. So the busy time estimation will be target
> dependent. Additionally on targets where the clocks are completely controlled
> by the on chip microcontroller, fetching and setting the current GPU frequency
> will be different. This patch aims to embrace these differences by re-factoring
> the devfreq code a bit.
>
> Signed-off-by: Sharat Masetty <smasetty@xxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 16 +++++++++---
> drivers/gpu/drm/msm/msm_gpu.c | 49 ++++++++++++++++++++---------------
> drivers/gpu/drm/msm/msm_gpu.h | 5 +++-
> 3 files changed, 44 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
> index 897f3e2..043e680 100644
> --- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
> @@ -1369,12 +1369,20 @@ static struct msm_ringbuffer *a5xx_active_ring(struct msm_gpu *gpu)
> return a5xx_gpu->cur_ring;
> }
>
> -static int a5xx_gpu_busy(struct msm_gpu *gpu, uint64_t *value)
> +static unsigned long a5xx_gpu_busy(struct msm_gpu *gpu)
> {
> - *value = gpu_read64(gpu, REG_A5XX_RBBM_PERFCTR_RBBM_0_LO,
> - REG_A5XX_RBBM_PERFCTR_RBBM_0_HI);
> + u64 busy_cycles;
> + unsigned long busy_time;
>
> - return 0;
> + busy_cycles = gpu_read64(gpu, REG_A5XX_RBBM_PERFCTR_RBBM_0_LO,
> + REG_A5XX_RBBM_PERFCTR_RBBM_0_HI);
> +
> + busy_time = (busy_cycles - gpu->devfreq.busy_cycles) /
> + (clk_get_rate(gpu->core_clk) / 1000000);
> +
> + gpu->devfreq.busy_cycles = busy_cycles;
> +
> + return busy_time;
> }
>
> static const struct adreno_gpu_funcs funcs = {
> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> index 8d6bc0c..26c1c3a 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.c
> +++ b/drivers/gpu/drm/msm/msm_gpu.c
> @@ -36,12 +36,16 @@ static int msm_devfreq_target(struct device *dev, unsigned long *freq,
> struct msm_gpu *gpu = platform_get_drvdata(to_platform_device(dev));
> struct dev_pm_opp *opp;
>
> - opp = dev_pm_opp_find_freq_ceil(dev, freq);
> + opp = devfreq_recommended_opp(dev, freq, flags);
> + if (IS_ERR(opp))
> + return PTR_ERR(opp);
>
> - if (!IS_ERR(opp)) {
> + if (gpu->funcs->gpu_set_freq)
> + gpu->funcs->gpu_set_freq(gpu, (u64)*freq);
Depending on how the interconnect patches end up looking it might make more
sense for us to send the OPP itself to gpu_set_freq() but we'll put a pin in
that until we know more.
Jordan
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