Re: [PATCH] wifi: brcmfmac: unmap dma buffer in brcmf_msgbuf_alloc_pktid()

[shaozhengchao <shaozhengchao@huawei.com>]

On 2022/12/22 16:46, Kalle Valo wrote:
> Sebastian Andrzej Siewior <bigeasy@linutronix.de> writes:
> 
>> On 2022-12-21 18:33:06 [+0000], Kalle Valo wrote:
>>> Zhengchao Shao <shaozhengchao@huawei.com> wrote:
>>>
>>>> After the DMA buffer is mapped to a physical address, address is stored
>>>> in pktids in brcmf_msgbuf_alloc_pktid(). Then, pktids is parsed in
>>>> brcmf_msgbuf_get_pktid()/brcmf_msgbuf_release_array() to obtain physaddr
>>>> and later unmap the DMA buffer. But when count is always equal to
>>>> pktids->array_size, physaddr isn't stored in pktids and the DMA buffer
>>>> will not be unmapped anyway.
>>>>
>>>> Fixes: 9a1bb60250d2 ("brcmfmac: Adding msgbuf protocol.")
>>>> Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
>>>
>>> Can someone review this?
>>
>> After looking at the code, that skb is mapped but not inserted into the
>> ringbuffer in this condition. The function returns with an error and the
>> caller will free that skb (or add to a list for later). Either way the
>> skb remains mapped which is wrong. The unmap here is the right thing to
>> do.
>>
>> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> 
> Thanks for the review, very much appreciated.
> 

Thank you very much.

Zhengchao Shao