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

From: oulijun <[email-masked]>
Date: Mon, 27 Jun 2016 16:31:33 +0800

Hi, Leon
在 2016/6/27 16:01, Leon Romanovsky 写道:
> 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 <zhaonenglong-C8/M+/[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.
> 
 You suggest to do as follows, right?
 in hns_roce_hw_v1.c
   int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool enable);

 and delete the keyword extern

 Bcause reserve the extern in hns_roce_hw_v1.c, the checkpatch is not pass.

>>
>>
>> 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);
> 
No warning.
However, the result of PClint checking is error, because the hns_roce_engine_reset have return value.

thanks
Lijun Ou

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