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

[Matthias Brugger]

On 21/09/2020 17:32, Chun-Kuang Hu wrote:
> Hi, Matthias:
>
> Matthias Brugger <matthias.bgg@xxxxxxxxx> 於 2020年9月21日 週一 下午4:53寫道：
> > On 21/09/2020 01:42, Chun-Kuang Hu wrote:
> > > For each client driver, its timeout handler need to dump hardware register
> > > or its state machine information, so remove timeout handler in helper
> > > function and let client driver implement its own timeout handler.
> >
> > I don't see the implementation of a client side handler. Did I miss something?
> > Would it make sense to instead add a callback to the handler in cmdq_mbox_create()?
>
> According to the commit message, it make sense to add a callback to
> the handler in comq_mbox_create().
> But for DRM, I would like to check timeout in vblank irq because the
> register should be applied in vblank. (I have not implement this patch
> yet)
> What I want to say is that different client may have different way to
> detect timeout and different way to handle it.
> If you want, I would add DRM timeout handle patch with this patch, and
> modify commit message to include different way to detect timeout.

I think that would help me to understand the whole picture.

Thanks a lot!
Matthias

> Regards,
> Chun-Kuang.
>
> > Regards,
> > Matthias
> >
> > > Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
> > > ---
> > >    drivers/gpu/drm/mediatek/mtk_drm_crtc.c |  3 +-
> > >    drivers/soc/mediatek/mtk-cmdq-helper.c  | 41 +------------------------
> > >    include/linux/soc/mediatek/mtk-cmdq.h   | 11 +------
> > >    3 files changed, 3 insertions(+), 52 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > > index 3fc5511330b9..cabeb7fea2be 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 dc644cfb6419..4f311f035b59 100644
> > > --- a/drivers/soc/mediatek/mtk-cmdq-helper.c
> > > +++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
> > > @@ -65,14 +65,7 @@ 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;
> > >
> > > @@ -80,12 +73,6 @@ 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;
> > > @@ -107,11 +94,6 @@ 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);
> > >    }
> > > @@ -342,18 +324,6 @@ 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) {
> > > @@ -366,7 +336,6 @@ 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;
> > > @@ -377,14 +346,6 @@ 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 2249ecaf77e4..175bd89f46f8 100644
> > > --- a/include/linux/soc/mediatek/mtk-cmdq.h
> > > +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> > > @@ -11,8 +11,6 @@
> > >    #include <linux/mailbox/mtk-cmdq-mailbox.h>
> > >    #include <linux/timer.h>
> > >
> > > -#define CMDQ_NO_TIMEOUT              0xffffffffu
> > > -
> > >    struct cmdq_pkt;
> > >
> > >    struct cmdq_client_reg {
> > > @@ -22,12 +20,8 @@ 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 */
> > >    };
> > >
> > >    /**
> > > @@ -49,13 +43,10 @@ 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