[PATCH v3 01/11] drm/tilcdc: Enable sync lost error and recovery handling for rev 1 LCDC

[Bartosz Golaszewski]

2016-11-22 17:54 GMT+01:00 Jyri Sarha <jsarha at ti.com>:
> Revision 1 LCDC support also sync lost errors and can benefit from
> sync lost recovery routine.
>
> Signed-off-by: Jyri Sarha <jsarha at ti.com>
> ---
>  drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 33 +++++++++++++++++----------------
>  drivers/gpu/drm/tilcdc/tilcdc_regs.h |  1 +
>  2 files changed, 18 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> index c787349..5260eb2 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> @@ -113,6 +113,7 @@ static void tilcdc_crtc_enable_irqs(struct drm_device *dev)
>
>         if (priv->rev == 1) {
>                 tilcdc_set(dev, LCDC_RASTER_CTRL_REG,
> +                       LCDC_V1_SYNC_LOST_ENA |
>                         LCDC_V1_UNDERFLOW_INT_ENA);
>                 tilcdc_set(dev, LCDC_DMA_CTRL_REG,
>                         LCDC_V1_END_OF_FRAME_INT_ENA);
> @@ -130,7 +131,7 @@ static void tilcdc_crtc_disable_irqs(struct drm_device *dev)
>
>         /* disable irqs that we might have enabled: */
>         if (priv->rev == 1) {
> -               tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
> +               tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_SYNC_LOST_ENA |
>                         LCDC_V1_UNDERFLOW_INT_ENA | LCDC_V1_PL_INT_ENA);
>                 tilcdc_clear(dev, LCDC_DMA_CTRL_REG,
>                         LCDC_V1_END_OF_FRAME_INT_ENA);
> @@ -845,6 +846,21 @@ irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
>                 dev_err_ratelimited(dev->dev, "%s(0x%08x): FIFO underflow",
>                                     __func__, stat);
>
> +       if (stat & LCDC_SYNC_LOST) {
> +               dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost",
> +                                   __func__, stat);
> +               tilcdc_crtc->frame_intact = false;
> +               if (tilcdc_crtc->sync_lost_count++ >
> +                   SYNC_LOST_COUNT_LIMIT) {
> +                       dev_err(dev->dev, "%s(0x%08x): Sync lost flood detected, recovering", __func__, stat);
> +                       queue_work(system_wq,
> +                                  &tilcdc_crtc->recover_work);
> +                       tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
> +                                    LCDC_SYNC_LOST);
> +                       tilcdc_crtc->sync_lost_count = 0;
> +               }
> +       }

We need to at least have tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
LCDC_RASTER_ENABLE) here - otherwise the recovery job doesn't even
start - as soon as we re-enable interrupts, we get a sync_lost irq
again.

> +
>         /* For revision 2 only */
>         if (priv->rev == 2) {
>                 if (stat & LCDC_FRAME_DONE) {
> @@ -852,21 +868,6 @@ irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
>                         wake_up(&tilcdc_crtc->frame_done_wq);
>                 }
>
> -               if (stat & LCDC_SYNC_LOST) {
> -                       dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost",
> -                                           __func__, stat);
> -                       tilcdc_crtc->frame_intact = false;
> -                       if (tilcdc_crtc->sync_lost_count++ >
> -                           SYNC_LOST_COUNT_LIMIT) {
> -                               dev_err(dev->dev, "%s(0x%08x): Sync lost flood detected, recovering", __func__, stat);
> -                               queue_work(system_wq,
> -                                          &tilcdc_crtc->recover_work);
> -                               tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG,
> -                                            LCDC_SYNC_LOST);
> -                               tilcdc_crtc->sync_lost_count = 0;
> -                       }
> -               }
> -
>                 /* Indicate to LCDC that the interrupt service routine has
>                  * completed, see 13.3.6.1.6 in AM335x TRM.
>                  */
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_regs.h b/drivers/gpu/drm/tilcdc/tilcdc_regs.h
> index f57c0d6..beb8c21 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_regs.h
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_regs.h
> @@ -61,6 +61,7 @@
>  #define LCDC_V2_UNDERFLOW_INT_ENA                BIT(5)
>  #define LCDC_V1_PL_INT_ENA                       BIT(4)
>  #define LCDC_V2_PL_INT_ENA                       BIT(6)
> +#define LCDC_V1_SYNC_LOST_ENA                    BIT(5)

I'd say we call it LCDC_V1_SYNC_LOST_INT_ENA for consistency.

Thanks,
Bartosz Golaszewski

>  #define LCDC_MONOCHROME_MODE                     BIT(1)
>  #define LCDC_RASTER_ENABLE                       BIT(0)
>  #define LCDC_TFT_ALT_ENABLE                      BIT(23)
> --
> 1.9.1
>