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Subject: Re: [PATCH v2] soc / drm: mediatek: cmdq: Remove timeout handler in
 helper function
To:     Chun-Kuang Hu <chunkuang.hu@kernel.org>
Cc:     linux-kernel <linux-kernel@vger.kernel.org>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>
References: <20201102000438.29225-1-chunkuang.hu@kernel.org>
 <CAAOTY_8c3WxPQ3igPojuF-3HbctQW0qiFM5GaqSuTDNcTSvvQA@mail.gmail.com>
From:   Matthias Brugger <matthias.bgg@gmail.com>
Message-ID: <4c00864c-a706-d73b-a8fb-e8e473db3f79@gmail.com>
Date:   Fri, 27 Nov 2020 13:40:12 +0100
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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@gmail.com>

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@kernel.org> 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@kernel.org>
>> ---
>> 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@kernel.org/
>> [2]
>> https://patchwork.kernel.org/project/linux-mediatek/patch/20201022094152.17662-1-houlong.wei@mediatek.com/
>>
>> 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
>>