[Nouveau] [PATCH 3/4] drm/nv50: avoid unloading pgraph context when ctxprog is running

[Maarten Maathuis]

Someone should probably check this out on earlier cards as well.

On Mon, Feb 1, 2010 at 7:34 PM, Maarten Maathuis <madman2003 at gmail.com> wrote:
> - We need to disable pgraph fifo access before checking the current channel,
> otherwise we could still hit a running ctxprog.
> - The writes to 0x400500 are already handled by pgraph->fifo_access and are
> therefore redundant, moreover pgraph fifo access should not be reenabled before
> current context is set as invalid. So remove them altogether.
>
> Signed-off-by: Maarten Maathuis <madman2003 at gmail.com>
> ---
>  drivers/gpu/drm/nouveau/nouveau_channel.c |    7 +++----
>  drivers/gpu/drm/nouveau/nv50_graph.c      |   10 +++++++---
>  2 files changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_channel.c b/drivers/gpu/drm/nouveau/nouveau_channel.c
> index 343d718..2281f99 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_channel.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_channel.c
> @@ -278,12 +278,11 @@ nouveau_channel_free(struct nouveau_channel *chan)
>        /* Ensure the channel is no longer active on the GPU */
>        pfifo->reassign(dev, false);
>
> -       if (pgraph->channel(dev) == chan) {
> -               pgraph->fifo_access(dev, false);
> +       pgraph->fifo_access(dev, false);
> +       if (pgraph->channel(dev) == chan)
>                pgraph->unload_context(dev);
> -               pgraph->fifo_access(dev, true);
> -       }
>        pgraph->destroy_context(chan);
> +       pgraph->fifo_access(dev, true);
>
>        if (pfifo->channel_id(dev) == chan->id) {
>                pfifo->disable(dev);
> diff --git a/drivers/gpu/drm/nouveau/nv50_graph.c b/drivers/gpu/drm/nouveau/nv50_graph.c
> index 20319e5..6d50480 100644
> --- a/drivers/gpu/drm/nouveau/nv50_graph.c
> +++ b/drivers/gpu/drm/nouveau/nv50_graph.c
> @@ -165,6 +165,12 @@ nv50_graph_channel(struct drm_device *dev)
>        uint32_t inst;
>        int i;
>
> +       /* Be sure we're not in the middle of a context switch or bad things
> +        * will happen, such as unloading the wrong pgraph context.
> +        */
> +       if (!nv_wait(0x400300, 0x00000001, 0x00000000))
> +               NV_ERROR(dev, "Ctxprog is still running\n");
> +
>        inst = nv_rd32(dev, NV50_PGRAPH_CTXCTL_CUR);
>        if (!(inst & NV50_PGRAPH_CTXCTL_CUR_LOADED))
>                return NULL;
> @@ -275,7 +281,7 @@ nv50_graph_load_context(struct nouveau_channel *chan)
>  int
>  nv50_graph_unload_context(struct drm_device *dev)
>  {
> -       uint32_t inst, fifo = nv_rd32(dev, 0x400500);
> +       uint32_t inst;
>
>        inst  = nv_rd32(dev, NV50_PGRAPH_CTXCTL_CUR);
>        if (!(inst & NV50_PGRAPH_CTXCTL_CUR_LOADED))
> @@ -283,12 +289,10 @@ nv50_graph_unload_context(struct drm_device *dev)
>        inst &= NV50_PGRAPH_CTXCTL_CUR_INSTANCE;
>
>        nouveau_wait_for_idle(dev);
> -       nv_wr32(dev, 0x400500, fifo & ~1);
>        nv_wr32(dev, 0x400784, inst);
>        nv_wr32(dev, 0x400824, nv_rd32(dev, 0x400824) | 0x20);
>        nv_wr32(dev, 0x400304, nv_rd32(dev, 0x400304) | 0x01);
>        nouveau_wait_for_idle(dev);
> -       nv_wr32(dev, 0x400500, fifo);
>
>        nv_wr32(dev, NV50_PGRAPH_CTXCTL_CUR, inst);
>        return 0;
> --
> 1.6.6.1
>
>