Re: [RFC PATCH 4/4] drm/rockchip: Add dmc notifier in vop driver

[dbasehore .]

On Wed, Jun 1, 2016 at 2:35 AM, Lin Huang <hl@xxxxxxxxxxxxxx> wrote:
> when in ddr frequency scaling process, vop can not do
> enable or disable operate, since dcf will base on vop vblank
> time to do frequency scaling and need to get vop irq if there
> have vop enabled. So need register to dmc notifier, and we can
> get the dmc status.
>
> Signed-off-by: Lin Huang <hl@xxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 51 +++++++++++++++++++++++++++--
>  1 file changed, 49 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> index 1c4d5b5..7ee0cd0 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -31,6 +31,8 @@
>  #include <linux/reset.h>
>  #include <linux/delay.h>
>
> +#include <soc/rockchip/rockchip_dmc.h>
> +
>  #include "rockchip_drm_drv.h"
>  #include "rockchip_drm_gem.h"
>  #include "rockchip_drm_fb.h"
> @@ -116,6 +118,9 @@ struct vop {
>
>         const struct vop_data *data;
>
> +       struct notifier_block dmc_nb;
> +       int dmc_in_process;
> +
>         uint32_t *regsbak;
>         void __iomem *regs;
>
> @@ -426,14 +431,41 @@ static void vop_dsp_hold_valid_irq_disable(struct vop *vop)
>         spin_unlock_irqrestore(&vop->irq_lock, flags);
>  }
>
> +static int dmc_notify(struct notifier_block *nb, unsigned long event,
> +                     void *data)
> +{
> +       struct vop *vop = container_of(nb, struct vop, dmc_nb);
> +
> +       if (event == DMCFREQ_ADJUST)
> +               vop->dmc_in_process = 1;
> +       else if (event == DMCFREQ_FINISH)
> +               vop->dmc_in_process = 0;
> +
> +       return NOTIFY_OK;
> +}
> +
>  static void vop_enable(struct drm_crtc *crtc)
>  {
>         struct vop *vop = to_vop(crtc);
>         int ret;
> +       int timeout_count = 500;
> +       int timeout_loop = 0;
>
>         if (vop->is_enabled)
>                 return;
>
> +       /*
> +        * if in dmc scaling frequency process, wait until it finish
> +        * use 100ms as timeout time.
> +        */
> +       while (timeout_loop < timeout_count) {
> +               if (vop->dmc_in_process == 0)
> +                       break;
> +
> +               timeout_loop++;
> +               usleep_range(150, 200);
> +       }

wait_event with wake_up_all should work better here than using usleep_range.

> +
>         ret = pm_runtime_get_sync(vop->dev);
>         if (ret < 0) {
>                 dev_err(vop->dev, "failed to get pm runtime: %d\n", ret);
> @@ -485,6 +517,7 @@ static void vop_enable(struct drm_crtc *crtc)
>         enable_irq(vop->irq);
>
>         drm_crtc_vblank_on(crtc);
> +       rockchip_dmc_get(&vop->dmc_nb);
>
>         return;
>
> @@ -500,11 +533,25 @@ static void vop_crtc_disable(struct drm_crtc *crtc)
>  {
>         struct vop *vop = to_vop(crtc);
>         int i;
> +       int timeout_count = 500;
> +       int timeout_loop = 0;
>
>         if (!vop->is_enabled)
>                 return;
>
>         /*
> +        * if in dmc scaling frequency process, wait until it finish
> +        * use 100ms as timeout time.
> +        */
> +       while (timeout_loop < timeout_count) {
> +               if (vop->dmc_in_process == 0)
> +                       break;
> +
> +               timeout_loop++;
> +               usleep_range(150, 200);
> +       }
> +
> +       /*
>          * We need to make sure that all windows are disabled before we
>          * disable that crtc. Otherwise we might try to scan from a destroyed
>          * buffer later.
> @@ -517,7 +564,7 @@ static void vop_crtc_disable(struct drm_crtc *crtc)
>                 VOP_WIN_SET(vop, win, enable, 0);
>                 spin_unlock(&vop->reg_lock);
>         }
> -
> +       rockchip_dmc_put(&vop->dmc_nb);
>         drm_crtc_vblank_off(crtc);
>
>         /*
> @@ -1243,7 +1290,7 @@ static int vop_create_crtc(struct vop *vop)
>                 ret = -ENOENT;
>                 goto err_cleanup_crtc;
>         }
> -
> +       vop->dmc_nb.notifier_call = dmc_notify;
>         init_completion(&vop->dsp_hold_completion);
>         init_completion(&vop->wait_update_complete);
>         crtc->port = port;
> --
> 1.9.1
>