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

From: Chun-Kuang Hu
Date: Thu Nov 19 2020 - 18:46:56 EST


Hi, Matthias:

I've provided the example for why of this patch. How do you think
about this patch?

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
>