Re: [PATCH v4 3/8] drm/mediatek: add shadow register support

From: CK Hu
Date: Mon Jul 18 2016 - 02:33:07 EST

Hi, YT:

One comment inline.


On Fri, 2016-07-15 at 18:07 +0800, YT Shen wrote:
> We need to acquire mutex before using the resources,
> and need to release it after finished.
> So we don't need to write registers in the blanking period.
>
> Signed-off-by: YT Shen <yt.shen@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 75 +++++++++++++++++++------------
> drivers/gpu/drm/mediatek/mtk_drm_ddp.c | 22 +++++++++
> drivers/gpu/drm/mediatek/mtk_drm_ddp.h | 2 +
> drivers/gpu/drm/mediatek/mtk_drm_drv.h | 1 +
> 4 files changed, 71 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 24aa3ba..80d9641 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -315,6 +315,42 @@ static void mtk_crtc_ddp_hw_fini(struct mtk_drm_crtc *mtk_crtc)
> pm_runtime_put(drm->dev);
> }
>
> +static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
> +{
> + struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> + struct mtk_crtc_state *state = to_mtk_crtc_state(mtk_crtc->base.state);
> + struct mtk_ddp_comp *ovl = mtk_crtc->ddp_comp[0];
> + unsigned int i;
> +
> + /*
> + * TODO: instead of updating the registers here, we should prepare
> + * working registers in atomic_commit and let the hardware command
> + * queue update module registers on vblank.
> + */
> + if (state->pending_config) {
> + mtk_ddp_comp_config(ovl, state->pending_width,
> + state->pending_height,
> + state->pending_vrefresh);
> +
> + state->pending_config = false;
> + }
> +
> + if (mtk_crtc->pending_planes) {
> + for (i = 0; i < OVL_LAYER_NR; i++) {
> + struct drm_plane *plane = &mtk_crtc->planes[i].base;
> + struct mtk_plane_state *plane_state;
> +
> + plane_state = to_mtk_plane_state(plane->state);
> +
> + if (plane_state->pending.config) {
> + mtk_ddp_comp_layer_config(ovl, i, plane_state);
> + plane_state->pending.config = false;
> + }
> + }
> + mtk_crtc->pending_planes = false;
> + }
> +}
> +
> static void mtk_drm_crtc_enable(struct drm_crtc *crtc)
> {
> struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> @@ -391,6 +427,7 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
> struct drm_crtc_state *old_crtc_state)
> {
> struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> + struct mtk_drm_private *priv = crtc->dev->dev_private;
> unsigned int pending_planes = 0;
> int i;
>
> @@ -409,6 +446,12 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
> }
> if (pending_planes)
> mtk_crtc->pending_planes = true;
> +
> + if (priv->data->shadow_register) {
> + mtk_disp_mutex_acquire(mtk_crtc->mutex);
> + mtk_crtc_ddp_config(crtc);
> + mtk_disp_mutex_release(mtk_crtc->mutex);
> + }
> }
>
> static const struct drm_crtc_funcs mtk_crtc_funcs = {
> @@ -453,36 +496,10 @@ err_cleanup_crtc:
> void mtk_crtc_ddp_irq(struct drm_crtc *crtc, struct mtk_ddp_comp *ovl)
> {
> struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> - struct mtk_crtc_state *state = to_mtk_crtc_state(mtk_crtc->base.state);
> - unsigned int i;
> + struct mtk_drm_private *priv = crtc->dev->dev_private;
>
> - /*
> - * TODO: instead of updating the registers here, we should prepare
> - * working registers in atomic_commit and let the hardware command
> - * queue update module registers on vblank.
> - */
> - if (state->pending_config) {
> - mtk_ddp_comp_config(ovl, state->pending_width,
> - state->pending_height,
> - state->pending_vrefresh);
> -
> - state->pending_config = false;
> - }
> -
> - if (mtk_crtc->pending_planes) {
> - for (i = 0; i < OVL_LAYER_NR; i++) {
> - struct drm_plane *plane = &mtk_crtc->planes[i].base;
> - struct mtk_plane_state *plane_state;
> -
> - plane_state = to_mtk_plane_state(plane->state);
> -
> - if (plane_state->pending.config) {
> - mtk_ddp_comp_layer_config(ovl, i, plane_state);
> - plane_state->pending.config = false;
> - }
> - }
> - mtk_crtc->pending_planes = false;
> - }
> + if (!priv->data->shadow_register)
> + mtk_crtc_ddp_config(crtc);
>
> mtk_drm_finish_page_flip(mtk_crtc);
> }
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp.c
> index 8030769..fa53806 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp.c
> @@ -12,6 +12,7 @@
> */
>
> #include <linux/clk.h>
> +#include <linux/iopoll.h>
> #include <linux/module.h>
> #include <linux/of_device.h>
> #include <linux/platform_device.h>
> @@ -32,6 +33,7 @@
> #define DISP_REG_CONFIG_MMSYS_CG_CON0 0x100
>
> #define DISP_REG_MUTEX_EN(n) (0x20 + 0x20 * (n))
> +#define DISP_REG_MUTEX(n) (0x24 + 0x20 * (n))
> #define DISP_REG_MUTEX_RST(n) (0x28 + 0x20 * (n))
> #define DISP_REG_MUTEX_MOD(n) (0x2c + 0x20 * (n))
> #define DISP_REG_MUTEX_SOF(n) (0x30 + 0x20 * (n))
> @@ -300,6 +302,26 @@ void mtk_disp_mutex_disable(struct mtk_disp_mutex *mutex)
> writel(0, ddp->regs + DISP_REG_MUTEX_EN(mutex->id));
> }
>
> +void mtk_disp_mutex_acquire(struct mtk_disp_mutex *mutex)
> +{
> + struct mtk_ddp *ddp = container_of(mutex, struct mtk_ddp,
> + mutex[mutex->id]);
> + u32 tmp;
> +
> + writel(1, ddp->regs + DISP_REG_MUTEX_EN(mutex->id));
> + writel(1, ddp->regs + DISP_REG_MUTEX(mutex->id));
> + readl_poll_timeout_atomic(ddp->regs + DISP_REG_MUTEX(mutex->id), tmp,
> + tmp & 0x2, 1, 10000);

Nothing to do with timeout? I think it should print error message here
or reset HW to recover it.

> +}
> +
> +void mtk_disp_mutex_release(struct mtk_disp_mutex *mutex)
> +{
> + struct mtk_ddp *ddp = container_of(mutex, struct mtk_ddp,
> + mutex[mutex->id]);
> +
> + writel(0, ddp->regs + DISP_REG_MUTEX(mutex->id));
> +}
> +
> static int mtk_ddp_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp.h b/drivers/gpu/drm/mediatek/mtk_drm_ddp.h
> index 92c1175..f9a7991 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp.h
> @@ -37,5 +37,7 @@ void mtk_disp_mutex_remove_comp(struct mtk_disp_mutex *mutex,
> enum mtk_ddp_comp_id id);
> void mtk_disp_mutex_unprepare(struct mtk_disp_mutex *mutex);
> void mtk_disp_mutex_put(struct mtk_disp_mutex *mutex);
> +void mtk_disp_mutex_acquire(struct mtk_disp_mutex *mutex);
> +void mtk_disp_mutex_release(struct mtk_disp_mutex *mutex);
>
> #endif /* MTK_DRM_DDP_H */
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> index fa0b106..94f8b66 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> @@ -33,6 +33,7 @@ struct mtk_mmsys_driver_data {
> unsigned int main_len;
> const enum mtk_ddp_comp_id *ext_path;
> unsigned int ext_len;
> + bool shadow_register;
> };
>
> struct mtk_drm_private {