From: tanhuazhong <tanhuazhong@huawei.com>
To: David Miller <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<salil.mehta@huawei.com>, <yisen.zhuang@huawei.com>,
<linuxarm@huawei.com>, <jakub.kicinski@netronome.com>
Subject: Re: [PATCH net] net: hns3: fix a wrong reset interrupt status mask
Date: Wed, 20 Nov 2019 09:36:44 +0800 [thread overview]
Message-ID: <707be979-7716-5669-ad91-ff0fdbcc101d@huawei.com> (raw)
In-Reply-To: <20191119.153603.2158592594523337284.davem@davemloft.net>
On 2019/11/20 7:36, David Miller wrote:
> From: Huazhong Tan <tanhuazhong@huawei.com>
> Date: Tue, 19 Nov 2019 10:31:48 +0800
>
>> According to hardware user manual, bits5~7 in register
>> HCLGE_MISC_VECTOR_INT_STS means reset interrupts status,
>> but HCLGE_RESET_INT_M is defined as bits0~2 now. So it
>> will make hclge_reset_err_handle() read the wrong reset
>> interrupt status.
>>
>> This patch fixes it and prints out the register value.
>>
>> Fixes: 2336f19d7892 ("net: hns3: check reset interrupt status when reset fails")
>> Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
>
> Fix exactly _one_ thing or else you make your patch hard to review.
>
> The bug is that the bits are wrong, just fix the bits!
>
ok, thanks
>>
>> + u32 msix_sts_reg;
>> +
>> + msix_sts_reg = hclge_read_dev(&hdev->hw, HCLGE_MISC_VECTOR_INT_STS);
>> +
>> if (hdev->reset_pending) {
>
> Now you are reading a register, and potentially clearing status bits and
> causing other side effects, that would not happen in this code path
> where hdev->reset_pending is true.
>
> Don't do stuff like this!
>
> If you want to add code to print out the register value, that is a
> separate patch, for net-next, and it must be done properly. In that
> you should only read the register in the same code paths you do
> previously. Otherwise you must _clearly_ explain why reading the
> register value in new code paths is OK, and the side effects will
> not potentially cause problems for the pending reset operation. It
> is still going to be a net-next improvement only.
>
> Thank you.
I will separate it, and resend the fix to -net.
Thanks.
>
> .
>
prev parent reply other threads:[~2019-11-20 1:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-19 2:31 [PATCH net] net: hns3: fix a wrong reset interrupt status mask Huazhong Tan
2019-11-19 23:36 ` David Miller
2019-11-20 1:36 ` tanhuazhong [this message]
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