Subject: Re: [PATCH v10 04/22] IB/hns: Add RoCE engine reset function

From: Leon Romanovsky <[email-masked]>
Date: Mon, 27 Jun 2016 11:01:22 +0300

On Sat, Jun 25, 2016 at 06:25:37PM +0800, Wei Hu (Xavier) wrote:
> 
> 
> On 2016/6/24 22:59, Leon Romanovsky wrote:
> >On Thu, Jun 16, 2016 at 10:35:12PM +0800, Lijun Ou wrote:
> >>This patch mainly added reset flow of RoCE engine in RoCE
> >>driver. It is necessary when RoCE is loaded and removed.
> >>
> >>Signed-off-by: Wei Hu <[email-masked]>
> >>Signed-off-by: Nenglong Zhao <[email-masked]>
> >>Signed-off-by: Lijun Ou <[email-masked]>
> >>---

...

> >>+
> >>+#define SLEEP_TIME_INTERVAL				20
> >>+
> >>+extern int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool enable);
> >Why did you add this extern?
> >You already exported this function.
> >drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c:EXPORT_SYMBOL(hns_dsaf_roce_reset);
> Hi, Leon
> 
>         The function named hns_dsaf_roce_reset is defined in hns_dsaf_main.c
>         It exists in hns_dsaf.ko(ethernet driver)
> 
>         RoCE driver will call this function.
> 
>         Your suggestion is that delete "extern" as below:
>             In /drivers/infiniband/hw/hns/hns_roce_hw_v1.h:
> 
>           int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool
> enable);
> 
> Right? or other soultion?

You placed it in header file.
Please move it to your hns_roce_hw_v1.c file.

> 
> 
> Regards
> Wei Hu
> >>+
> >>+#endif
> >>diff --git a/drivers/infiniband/hw/hns/hns_roce_main.c b/drivers/infiniband/hw/hns/hns_roce_main.c
> >>index 8924ce3..d5ccce2 100644
> >>--- a/drivers/infiniband/hw/hns/hns_roce_main.c
> >>+++ b/drivers/infiniband/hw/hns/hns_roce_main.c
> >>@@ -71,7 +71,9 @@ static int hns_roce_get_cfg(struct hns_roce_dev *hr_dev)
> >>  	struct platform_device *pdev = NULL;
> >>  	struct resource *res;
> >>-	if (!of_device_is_compatible(np, "hisilicon,hns-roce-v1")) {
> >>+	if (of_device_is_compatible(np, "hisilicon,hns-roce-v1")) {
> >>+		hr_dev->hw = &hns_roce_hw_v1;
> >>+	} else {
> >>  		dev_err(dev, "device no compatible!\n");
> >>  		return -EINVAL;
> >>  	}
> >>@@ -118,6 +120,11 @@ static int hns_roce_get_cfg(struct hns_roce_dev *hr_dev)
> >>  	return 0;
> >>  }
> >>+static int hns_roce_engine_reset(struct hns_roce_dev *hr_dev, bool enable)
> >>+{
> >>+	return hr_dev->hw->reset(hr_dev, enable);
> >>+}
> >>+
> >>  /**
> >>  * hns_roce_probe - RoCE driver entrance
> >>  * @pdev: pointer to platform device
> >>@@ -156,6 +163,12 @@ static int hns_roce_probe(struct platform_device *pdev)
> >>  		goto error_failed_get_cfg;
> >>  	}
> >>+	ret = hns_roce_engine_reset(hr_dev, true);
> >Do you have better solution to sense device without doing full reset of
> >your hardware?
> Hi, Leon
> 
>     In this place, we need reset RoCEE engine to ensure that RoCE engine can
> work correctly.
>     Hip06 Soc only support full reset RoCEE engine.
> 
> Regards
> Wei Hu
> 
> >
> >>+	if (ret) {
> >>+		dev_err(dev, "Reset roce engine failed!\n");
> >>+		goto error_failed_get_cfg;
> >>+	}
> >>+
> >>  error_failed_get_cfg:
> >>  	ib_dealloc_device(&hr_dev->ib_dev);
> >>@@ -170,6 +183,8 @@ static int hns_roce_remove(struct platform_device *pdev)
> >>  {
> >>  	struct hns_roce_dev *hr_dev = platform_get_drvdata(pdev);
> >>+	(void)hns_roce_engine_reset(hr_dev, false);
> >Any reason to do explicit casting?
> Hi, Leon
> 
> /**
>  * hns_roce_engine_reset - reset roce
>  * @hr_dev: roce device struct pointer
>  * @enable: true -- drop reset, false -- reset
>  * return 0 - success , negative --fail
>  */
> static int hns_roce_engine_reset(struct hns_roce_dev *hr_dev, bool enable);
> 
> hns_roce_engine_reset->hns_roce_v1_reset->hns_dsaf_roce_reset
> 
> The err branch of hns_roce_engine_reset as below：
> int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool enable)
> {
>     <...>
>     if (!is_of_node(dsaf_fwnode)) {
>         pr_err("hisi_dsaf: Only support DT node!\n");
>         return -EINVAL;
>     }
> 
>     pdev = of_find_device_by_node(to_of_node(dsaf_fwnode));
>     dsaf_dev = dev_get_drvdata(&pdev->dev);
>     if (AE_IS_VER1(dsaf_dev->dsaf_ver)) {
>         dev_err(dsaf_dev->dev, "%s v1 chip do not support roce!\n",
>             dsaf_dev->ae_dev.name);
>         return -ENODEV;
>     }
>     <...>
> }
> 
>    When the cpu is processing hns_roce_engine_reset(hr_dev, false),
> hns_roce_engine_reset(hr_dev, true)  have been alomost processed
> sucessfully.
>    From the err branch of hns_roce_engine_reset, we found at this time
> hns_roce_engine_reset(hr_dev, true) could not return err.
> 
> In hns_roce_remove function, we call hns_roce_engine_reset(hr_dev, false),
> and doesn't need to judge the return value.

Do you see any compilation warning for this part of code?

    struct hns_roce_dev *hr_dev = platform_get_drvdata(pdev);
+   hns_roce_engine_reset(hr_dev, false);

instead of

    struct hns_roce_dev *hr_dev = platform_get_drvdata(pdev);
+   (void)hns_roce_engine_reset(hr_dev, false);