Re: [PATCH v2] soc / drm: mediatek: cmdq: Remove timeout handler in helper function

[Matthias Brugger]

Hi Chun-Kuang,

On 20/11/2020 00:46, Chun-Kuang Hu wrote:
> Hi, Matthias:
>
> I've provided the example for why of this patch. How do you think
> about this patch?

Patch looks good to me. If you want to take it through your tree you can add my
Acked-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>

Beware that you might need a stable tag for it, so that I can merge it into my 
soc branch, in case there are more changes to cmdq-helper.

Regards,
Matthias

> Regards,
> Chun-Kuang.
>
> Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx> 於 2020年11月2日 週一 上午8:04寫道：
> > For each client driver, its timeout handler need to dump hardware register
> > or its state machine information, and their way to detect timeout are
> > also different, so remove timeout handler in helper function and
> > let client driver implement its own timeout handler.
> >
> > Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
> > ---
> > v1 is one patch in series "Mediatek DRM driver detect CMDQ execution
> > timeout by vblank IRQ", but according to Jassi's suggestion [1], send
> > each patch in different series.
> >
> > [2] is an example that different client has different way to calculate
> > timeout. Some client driver care about each packet's execution time, but
> > some client driver care about the total execution time for all packets.
> >
> > [1]
> > https://patchwork.kernel.org/project/linux-mediatek/cover/20200927230422.11610-1-chunkuang.hu@xxxxxxxxxx/
> > [2]
> > https://patchwork.kernel.org/project/linux-mediatek/patch/20201022094152.17662-1-houlong.wei@xxxxxxxxxxxx/
> >
> > Changes in v2:
> > 1. Rebase onto Linux 5.10-rc1
> > ---
> >   drivers/gpu/drm/mediatek/mtk_drm_crtc.c |  3 +-
> >   drivers/soc/mediatek/mtk-cmdq-helper.c  | 41 +------------------------
> >   include/linux/soc/mediatek/mtk-cmdq.h   | 10 +-----
> >   3 files changed, 3 insertions(+), 51 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > index ac038572164d..4be5d1fccf2e 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > @@ -824,8 +824,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> >   #if IS_REACHABLE(CONFIG_MTK_CMDQ)
> >          mtk_crtc->cmdq_client =
> >                          cmdq_mbox_create(mtk_crtc->mmsys_dev,
> > -                                        drm_crtc_index(&mtk_crtc->base),
> > -                                        2000);
> > +                                        drm_crtc_index(&mtk_crtc->base));
> >          if (IS_ERR(mtk_crtc->cmdq_client)) {
> >                  dev_dbg(dev, "mtk_crtc %d failed to create mailbox client, writing register by CPU now\n",
> >                          drm_crtc_index(&mtk_crtc->base));
> > diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > index 505651b0d715..280d3bd9f675 100644
> > --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> > +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > @@ -70,14 +70,7 @@ int cmdq_dev_get_client_reg(struct device *dev,
> >   }
> >   EXPORT_SYMBOL(cmdq_dev_get_client_reg);
> >
> > -static void cmdq_client_timeout(struct timer_list *t)
> > -{
> > -       struct cmdq_client *client = from_timer(client, t, timer);
> > -
> > -       dev_err(client->client.dev, "cmdq timeout!\n");
> > -}
> > -
> > -struct cmdq_client *cmdq_mbox_create(struct device *dev, int index, u32 timeout)
> > +struct cmdq_client *cmdq_mbox_create(struct device *dev, int index)
> >   {
> >          struct cmdq_client *client;
> >
> > @@ -85,12 +78,6 @@ struct cmdq_client *cmdq_mbox_create(struct device *dev, int index, u32 timeout)
> >          if (!client)
> >                  return (struct cmdq_client *)-ENOMEM;
> >
> > -       client->timeout_ms = timeout;
> > -       if (timeout != CMDQ_NO_TIMEOUT) {
> > -               spin_lock_init(&client->lock);
> > -               timer_setup(&client->timer, cmdq_client_timeout, 0);
> > -       }
> > -       client->pkt_cnt = 0;
> >          client->client.dev = dev;
> >          client->client.tx_block = false;
> >          client->client.knows_txdone = true;
> > @@ -112,11 +99,6 @@ EXPORT_SYMBOL(cmdq_mbox_create);
> >
> >   void cmdq_mbox_destroy(struct cmdq_client *client)
> >   {
> > -       if (client->timeout_ms != CMDQ_NO_TIMEOUT) {
> > -               spin_lock(&client->lock);
> > -               del_timer_sync(&client->timer);
> > -               spin_unlock(&client->lock);
> > -       }
> >          mbox_free_channel(client->chan);
> >          kfree(client);
> >   }
> > @@ -449,18 +431,6 @@ static void cmdq_pkt_flush_async_cb(struct cmdq_cb_data data)
> >          struct cmdq_task_cb *cb = &pkt->cb;
> >          struct cmdq_client *client = (struct cmdq_client *)pkt->cl;
> >
> > -       if (client->timeout_ms != CMDQ_NO_TIMEOUT) {
> > -               unsigned long flags = 0;
> > -
> > -               spin_lock_irqsave(&client->lock, flags);
> > -               if (--client->pkt_cnt == 0)
> > -                       del_timer(&client->timer);
> > -               else
> > -                       mod_timer(&client->timer, jiffies +
> > -                                 msecs_to_jiffies(client->timeout_ms));
> > -               spin_unlock_irqrestore(&client->lock, flags);
> > -       }
> > -
> >          dma_sync_single_for_cpu(client->chan->mbox->dev, pkt->pa_base,
> >                                  pkt->cmd_buf_size, DMA_TO_DEVICE);
> >          if (cb->cb) {
> > @@ -473,7 +443,6 @@ int cmdq_pkt_flush_async(struct cmdq_pkt *pkt, cmdq_async_flush_cb cb,
> >                           void *data)
> >   {
> >          int err;
> > -       unsigned long flags = 0;
> >          struct cmdq_client *client = (struct cmdq_client *)pkt->cl;
> >
> >          pkt->cb.cb = cb;
> > @@ -484,14 +453,6 @@ int cmdq_pkt_flush_async(struct cmdq_pkt *pkt, cmdq_async_flush_cb cb,
> >          dma_sync_single_for_device(client->chan->mbox->dev, pkt->pa_base,
> >                                     pkt->cmd_buf_size, DMA_TO_DEVICE);
> >
> > -       if (client->timeout_ms != CMDQ_NO_TIMEOUT) {
> > -               spin_lock_irqsave(&client->lock, flags);
> > -               if (client->pkt_cnt++ == 0)
> > -                       mod_timer(&client->timer, jiffies +
> > -                                 msecs_to_jiffies(client->timeout_ms));
> > -               spin_unlock_irqrestore(&client->lock, flags);
> > -       }
> > -
> >          err = mbox_send_message(client->chan, pkt);
> >          if (err < 0)
> >                  return err;
> > diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
> > index 960704d75994..8e9996610978 100644
> > --- a/include/linux/soc/mediatek/mtk-cmdq.h
> > +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> > @@ -11,7 +11,6 @@
> >   #include <linux/mailbox/mtk-cmdq-mailbox.h>
> >   #include <linux/timer.h>
> >
> > -#define CMDQ_NO_TIMEOUT                0xffffffffu
> >   #define CMDQ_ADDR_HIGH(addr)   ((u32)(((addr) >> 16) & GENMASK(31, 0)))
> >   #define CMDQ_ADDR_LOW(addr)    ((u16)(addr) | BIT(1))
> >
> > @@ -24,12 +23,8 @@ struct cmdq_client_reg {
> >   };
> >
> >   struct cmdq_client {
> > -       spinlock_t lock;
> > -       u32 pkt_cnt;
> >          struct mbox_client client;
> >          struct mbox_chan *chan;
> > -       struct timer_list timer;
> > -       u32 timeout_ms; /* in unit of microsecond */
> >   };
> >
> >   /**
> > @@ -51,13 +46,10 @@ int cmdq_dev_get_client_reg(struct device *dev,
> >    * cmdq_mbox_create() - create CMDQ mailbox client and channel
> >    * @dev:       device of CMDQ mailbox client
> >    * @index:     index of CMDQ mailbox channel
> > - * @timeout:   timeout of a pkt execution by GCE, in unit of microsecond, set
> > - *             CMDQ_NO_TIMEOUT if a timer is not used.
> >    *
> >    * Return: CMDQ mailbox client pointer
> >    */
> > -struct cmdq_client *cmdq_mbox_create(struct device *dev, int index,
> > -                                    u32 timeout);
> > +struct cmdq_client *cmdq_mbox_create(struct device *dev, int index);
> >
> >   /**
> >    * cmdq_mbox_destroy() - destroy CMDQ mailbox client and channel
> > --
> > 2.17.1