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Subject: Re: [PATCH -next] net: wwan: t7xx: use GFP_ATOMIC under spin lock in
 t7xx_cldma_gpd_set_next_ptr()
To:     Loic Poulain <loic.poulain@linaro.org>
CC:     <linux-kernel@vger.kernel.org>,
        <linux-mediatek@lists.infradead.org>,
        <linux-arm-kernel@lists.infradead.org>, <netdev@vger.kernel.org>,
        <haijun.liu@mediatek.com>, <chandrashekar.devegowda@intel.com>,
        <ricardo.martinez@linux.intel.com>, <davem@davemloft.net>,
        <kuba@kernel.org>
References: <20220518090738.2694556-1-yangyingliang@huawei.com>
 <CAMZdPi9uvh4E70-AXpGrdzkgh35mfWQbhL8Kxw_o9_DsfL2gbw@mail.gmail.com>
From:   Yang Yingliang <yangyingliang@huawei.com>
Message-ID: <53b384f6-5507-b767-f64a-574cfd511e13@huawei.com>
Date:   Thu, 19 May 2022 09:52:30 +0800
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Hi,

On 2022/5/18 17:13, Loic Poulain wrote:
> Hi Yang,
>
> On Wed, 18 May 2022 at 10:57, Yang Yingliang <yangyingliang@huawei.com> wrote:
>> Sometimes t7xx_cldma_gpd_set_next_ptr() is called under spin lock,
>> so add a parameter in t7xx_cldma_gpd_set_next_ptr() to make if it
>> use GFP_ATOMIC flag.
>>
>> Fixes: 39d439047f1d ("net: wwan: t7xx: Add control DMA interface")
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>> ---
>>   drivers/net/wwan/t7xx/t7xx_hif_cldma.c | 13 ++++++++-----
>>   1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/net/wwan/t7xx/t7xx_hif_cldma.c b/drivers/net/wwan/t7xx/t7xx_hif_cldma.c
>> index 0c52801ed0de..1fa9bb763831 100644
>> --- a/drivers/net/wwan/t7xx/t7xx_hif_cldma.c
>> +++ b/drivers/net/wwan/t7xx/t7xx_hif_cldma.c
>> @@ -91,9 +91,12 @@ static void t7xx_cldma_gpd_set_next_ptr(struct cldma_gpd *gpd, dma_addr_t next_p
>>   }
>>
>>   static int t7xx_cldma_alloc_and_map_skb(struct cldma_ctrl *md_ctrl, struct cldma_request *req,
>> -                                       size_t size)
>> +                                       size_t size, bool is_atomic)
> Would be simpler to directly pass the gfp_mask as a parameter.
Yes, I will send a v2 with this change later.

Thanks,
Yang
>
>
>>   {
>> -       req->skb = __dev_alloc_skb(size, GFP_KERNEL);
>> +       if (is_atomic)
>> +               req->skb = __dev_alloc_skb(size, GFP_ATOMIC);
>> +       else
>> +               req->skb = __dev_alloc_skb(size, GFP_KERNEL);
>>          if (!req->skb)
>>                  return -ENOMEM;
>>
>> @@ -174,7 +177,7 @@ static int t7xx_cldma_gpd_rx_from_q(struct cldma_queue *queue, int budget, bool
>>                  spin_unlock_irqrestore(&queue->ring_lock, flags);
>>                  req = queue->rx_refill;
>>
>> -               ret = t7xx_cldma_alloc_and_map_skb(md_ctrl, req, queue->tr_ring->pkt_size);
>> +               ret = t7xx_cldma_alloc_and_map_skb(md_ctrl, req, queue->tr_ring->pkt_size, false);
>>                  if (ret)
>>                          return ret;
>>
>> @@ -402,7 +405,7 @@ static struct cldma_request *t7xx_alloc_rx_request(struct cldma_ctrl *md_ctrl, s
>>          if (!req->gpd)
>>                  goto err_free_req;
>>
>> -       val = t7xx_cldma_alloc_and_map_skb(md_ctrl, req, pkt_size);
>> +       val = t7xx_cldma_alloc_and_map_skb(md_ctrl, req, pkt_size, false);
>>          if (val)
>>                  goto err_free_pool;
>>
>> @@ -801,7 +804,7 @@ static int t7xx_cldma_clear_rxq(struct cldma_ctrl *md_ctrl, int qnum)
>>                  if (req->skb)
>>                          continue;
>>
>> -               ret = t7xx_cldma_alloc_and_map_skb(md_ctrl, req, rxq->tr_ring->pkt_size);
>> +               ret = t7xx_cldma_alloc_and_map_skb(md_ctrl, req, rxq->tr_ring->pkt_size, true);
>>                  if (ret)
>>                          break;
>>
>> --
>> 2.25.1
>>
> .