stm32H7 hal 庫(kù)里面的以太網(wǎng)代碼，坑了魚(yú)鷹很多次（不知道最新版是否已經(jīng)修復(fù)了這些bug），這里分享一篇網(wǎng)上的文章，因?yàn)轸~(yú)鷹也遇到過(guò)，靠它解決了其中一個(gè)編譯優(yōu)化問(wèn)題，在此感謝作者。不過(guò)hal庫(kù)里面遠(yuǎn)不止這些bug（主要是項(xiàng)目環(huán)境太復(fù)雜了，一般情況很難觸發(fā)），還有更多bug沒(méi)在此文章描述，而魚(yú)鷹碰到了......

問(wèn)題

最近在調(diào)試STM32H750+LAN8720，搞了大半天終于移植好LwIP了，ping也能ping通，TCP測(cè)試也成功。本來(lái)以為ST的HAL庫(kù)終于省心了，結(jié)果我將編譯優(yōu)化開(kāi)到最大…

…直接ping都ping不通了。后來(lái)發(fā)現(xiàn)HAL庫(kù)有很大問(wèn)題。(果然HAL庫(kù)還是不省心，生成的代碼只有初始化能用)

后面發(fā)現(xiàn)，HAL庫(kù)有兩個(gè)隱患:

1、對(duì)描述符的處理有問(wèn)題

2、因?yàn)?a target="_blank">單片機(jī)是Cortex-M7，有Cache和單片機(jī)會(huì)亂序執(zhí)行和亂序訪問(wèn)內(nèi)存，亂序訪問(wèn)對(duì)發(fā)送/接收描述符 操作有很大的隱患

后面對(duì)這些問(wèn)題詳細(xì)描述

原因

問(wèn)題1 HAL庫(kù)的隱患1 處理方式

我感覺(jué)HAL庫(kù)處理數(shù)據(jù)描述符的方式似乎很有問(wèn)題，例如

SET_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCRF_OWN);//居然在這里將描述符權(quán)限給了ETH


if(dmarxdesclist->ItMode != 0U)
{
  SET_BIT(dmarxdesc->DESC3,ETH_DMARXNDESCRF_IOC);//描述符都給了ETH居然還要修改
}

這是stm32h7xx_hal_eth.c中

HAL_StatusTypeDef HAL_ETH_BuildRxDescriptors(ETH_HandleTypeDef *heth)

的一段代碼，描述符的OWN在我看來(lái)應(yīng)該是最后才設(shè)置的，因?yàn)樗菢?biāo)記描述符當(dāng)前是ETH所有還是用戶(CPU等其他玩意)所有，但從這段代碼看來(lái)，它把描述符歸還ETH后居然還對(duì)這個(gè)描述符進(jìn)行修改，這是要趁ETH不注意嗎，如果真是這樣，ETH還真的能正常運(yùn)行！但是這無(wú)疑是一個(gè)安全隱患。一個(gè)直接體現(xiàn)就是我把編譯優(yōu)化打開(kāi)(-O3)以太網(wǎng)通信就出問(wèn)題了。

并且這種操作在HAL庫(kù)里隨處可見(jiàn)，簡(jiǎn)直恐怖如斯

估摸著ST的人以為寫(xiě)入ETH->DMACRDTPR或者ETH->DMACTDTPR(用于告訴ETH描述符有更新)描述符才會(huì)生效，但我看了文檔的描述，如果應(yīng)用程序能一直更新描述符，即使不寫(xiě)入這個(gè)寄存器，ETH還是會(huì)接著發(fā)送，即描述符的OWN位的設(shè)置為1代表著描述符歸ETH所有，送出去的描述符潑出去的水，用戶不應(yīng)該再進(jìn)行修改，直到OWN被ETH清零。那ETH->DMACRDTPR或者ETH->DMACTDTPR的用處是什么呢？為了減少ETH對(duì)總線的占用，如果ETH檢測(cè)不到有效的描述符(OWN都為0)，ETH將不再訪問(wèn)內(nèi)存，所以需要一個(gè)機(jī)制來(lái)告訴ETH描述符有更新，該干活了。

而這個(gè)機(jī)制就是寫(xiě)入ETH->DMACRDTPR(接收描述符)或者ETH->DMACTDTPR(發(fā)送描述符)，這兩個(gè)寄存器除了標(biāo)記最后一個(gè)描述符的地址，還用于告訴ETH描述符有更新。

問(wèn)題2 HAL庫(kù)的隱患2 沒(méi)有處理Cortex-M7的亂序訪問(wèn)和Cache的問(wèn)題

正常來(lái)說(shuō)，CPU的亂序執(zhí)行是不會(huì)影響外設(shè)操作的。因?yàn)橥庠O(shè)寄存器的內(nèi)存類型默認(rèn)為Device(還要一個(gè)類似的屬性為Strongly-ordered)，這意味著亂序執(zhí)行無(wú)論在怎么亂，它都會(huì)保證對(duì)這些內(nèi)存正確的順序(在代碼中的執(zhí)行順序)訪問(wèn)。

但巧了，描述符的存放位置不在這些內(nèi)存區(qū)域，它只能放在D2域的SRAM中(ETH的手只能夠著這些地方)，而且這些SRAM的內(nèi)存類型默認(rèn)為Normal，而為了效率，CPU會(huì)對(duì)這些區(qū)域的內(nèi)存亂序訪問(wèn)(這樣關(guān)鍵的OWN位可能提前也可能延后被寫(xiě)入)，這肯定不是我們希望的。

對(duì)于開(kāi)啟了Cache的情況，這將變得更加復(fù)雜，可能寫(xiě)入的數(shù)據(jù)都沒(méi)有實(shí)實(shí)在在的寫(xiě)入內(nèi)存中。

解決方法

對(duì)于問(wèn)題1，對(duì)描述符操作的代碼沒(méi)多少，我就自己手動(dòng)修改了stm32h7xx_hal_eth.c中的相關(guān)代碼(修改過(guò)的部分在后面放出)，保證代碼的順序是沒(méi)問(wèn)題的。主要修改OWN相關(guān)的和ETH->DMACRDTPR和ETH->DMACTDTPR相關(guān)的。

對(duì)于問(wèn)題2，我是這么處理的：

配置MPU，將描述符，數(shù)據(jù)緩存所在的內(nèi)存區(qū)域配置為不緩沖(Buffer)，不緩存(Cache)，TEX配置為L(zhǎng)EVEL1(0x01)，這樣這些內(nèi)存就配置為了Normal，但不再受Cache的影響(這保證了一個(gè)性能的平衡，因?yàn)閷?duì)于CortexM7,CleanCache操作步驟太多，雖然就調(diào)用了一個(gè)內(nèi)聯(lián)的函數(shù)，但其中是寫(xiě)一次寄存器Clean一個(gè)Cache行，整個(gè)Cache需要512次寫(xiě)操作還有其他相關(guān)的計(jì)算，還不如不Cache這些地方的內(nèi)存，而使用Normal屬性能加快內(nèi)存訪問(wèn)速度（它似乎能把多個(gè)連續(xù)單字節(jié)的訪問(wèn)打包成32Bit的訪問(wèn)，應(yīng)該是亂序訪問(wèn)的功勞，這個(gè)特性是我調(diào)試SDRAM測(cè)試它的速度時(shí)發(fā)現(xiàn)的，即使沒(méi)有使能Cache，配置成Normal的訪問(wèn)速度比Device要快）)

在設(shè)置/清零OWN操作的前后加入__DMB()內(nèi)存隔離指令(要大寫(xiě)的，自帶編譯隔離，防止這個(gè)指令被編譯器重排，沒(méi)想到吧，編譯器也會(huì)把你的指令打亂)

LwIP的版本為2.1.0

修改完之后，單片機(jī)端使用socket API創(chuàng)建的tcp服務(wù)器，單向傳輸10MB/s，相當(dāng)于80Mbps帶寬，離物理能達(dá)到的100Mbps還差一點(diǎn)，但CPU占用率已經(jīng)達(dá)到了80，90多(TCP應(yīng)該比較消耗性能吧)，估計(jì)協(xié)議和性能的損耗比較大。

修改的代碼

只需要修改stm32h7xx_hal_eth.c的代碼

發(fā)送的修改

發(fā)送相關(guān)的有三個(gè)函數(shù)被修改

static uint32_t ETH_Prepare_Tx_Descriptors(ETH_HandleTypeDef *heth, ETH_TxPacketConfig *pTxConfig, uint32_t ItMode)
{
  ETH_TxDescListTypeDef *dmatxdesclist = &heth->TxDescList;
  uint32_t descidx = dmatxdesclist->CurTxDesc;
  uint32_t firstdescidx = dmatxdesclist->CurTxDesc;
  uint32_t descnbr = 0, idx;
  ETH_DMADescTypeDef *dmatxdesc = (ETH_DMADescTypeDef *)dmatxdesclist->TxDesc[descidx];


  ETH_BufferTypeDef  *txbuffer = pTxConfig->TxBuffer;
  uint32_t           bd_count = 0;


  /* Current Tx Descriptor Owned by DMA: cannot be used by the application  */
  if((READ_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCWBF_OWN) == ETH_DMATXNDESCWBF_OWN) || (dmatxdesclist->PacketAddress[descidx] != NULL))
  {
    return HAL_ETH_ERROR_BUSY;
  }


  /***************************************************************************/
  /*****************    Context descriptor configuration (Optional) **********/
  /***************************************************************************/
  /* If VLAN tag is enabled for this packet */
  if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_VLANTAG) != 0U)
  {
    /* Set vlan tag value */
    MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXCDESC_VT, pTxConfig->VlanTag);
    /* Set vlan tag valid bit */
    SET_BIT(dmatxdesc->DESC3, ETH_DMATXCDESC_VLTV);
    /* Set the descriptor as the vlan input source */
    SET_BIT(heth->Instance->MACVIR, ETH_MACVIR_VLTI);


    /* if inner VLAN is enabled */
    if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_INNERVLANTAG) != 0U)
    {
      /* Set inner vlan tag value */
      MODIFY_REG(dmatxdesc->DESC2, ETH_DMATXCDESC_IVT, (pTxConfig->InnerVlanTag << 16));
      /* Set inner vlan tag valid bit */
      SET_BIT(dmatxdesc->DESC3, ETH_DMATXCDESC_IVLTV);


      /* Set Vlan Tag control */
      MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXCDESC_IVTIR, pTxConfig->InnerVlanCtrl);


      /* Set the descriptor as the inner vlan input source */
      SET_BIT(heth->Instance->MACIVIR, ETH_MACIVIR_VLTI);
      /* Enable double VLAN processing */
      SET_BIT(heth->Instance->MACVTR, ETH_MACVTR_EDVLP);
    }
  }


  /* if tcp segmentation is enabled for this packet */
  if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_TSO) != 0U)
  {
    /* Set MSS value */
    MODIFY_REG(dmatxdesc->DESC2, ETH_DMATXCDESC_MSS, pTxConfig->MaxSegmentSize);
    /* Set MSS valid bit */
    SET_BIT(dmatxdesc->DESC3, ETH_DMATXCDESC_TCMSSV);
  }


  if((READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_VLANTAG) != 0U)|| (READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_TSO) != 0U))
  {
    /* Set as context descriptor */
    SET_BIT(dmatxdesc->DESC3, ETH_DMATXCDESC_CTXT);
    /* Set own bit */
    SET_BIT(dmatxdesc->DESC3, ETH_DMATXCDESC_OWN);
    /* Increment current tx descriptor index */
    INCR_TX_DESC_INDEX(descidx, 1U);
    /* Get current descriptor address */
    dmatxdesc = (ETH_DMADescTypeDef *)dmatxdesclist->TxDesc[descidx];


    descnbr += 1U;


    /* Current Tx Descriptor Owned by DMA: cannot be used by the application  */
    if(READ_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCWBF_OWN) == ETH_DMATXNDESCWBF_OWN)
    {
      dmatxdesc = (ETH_DMADescTypeDef *)dmatxdesclist->TxDesc[firstdescidx];
      /* Clear own bit */
      CLEAR_BIT(dmatxdesc->DESC3, ETH_DMATXCDESC_OWN);


      return HAL_ETH_ERROR_BUSY;
    }
  }


  /***************************************************************************/
  /*****************    Normal descriptors configuration     *****************/
  /***************************************************************************/


  descnbr += 1U;


  /* Set header or buffer 1 address */
  WRITE_REG(dmatxdesc->DESC0, (uint32_t)txbuffer->buffer);
  /* Set header or buffer 1 Length */
  MODIFY_REG(dmatxdesc->DESC2, ETH_DMATXNDESCRF_B1L, txbuffer->len);


  if(txbuffer->next != NULL)
  {
    txbuffer = txbuffer->next;
    /* Set buffer 2 address */
    WRITE_REG(dmatxdesc->DESC1, (uint32_t)txbuffer->buffer);
    /* Set buffer 2 Length */
    MODIFY_REG(dmatxdesc->DESC2, ETH_DMATXNDESCRF_B2L, (txbuffer->len << 16));
  }
  else
  {
    WRITE_REG(dmatxdesc->DESC1, 0x0);
    /* Set buffer 2 Length */
    MODIFY_REG(dmatxdesc->DESC2, ETH_DMATXNDESCRF_B2L, 0x0U);
  }


  if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_TSO) != 0U)
  {
    /* Set TCP Header length */
    MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXNDESCRF_THL, (pTxConfig->TCPHeaderLen << 19));
    /* Set TCP payload length */
    MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXNDESCRF_TPL, pTxConfig->PayloadLen);
    /* Set TCP Segmentation Enabled bit */
    SET_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_TSE);
  }
  else
  {
    MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXNDESCRF_FL, pTxConfig->Length);


    if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_CSUM) != 0U)
    {
      MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXNDESCRF_CIC, pTxConfig->ChecksumCtrl);
    }


    if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_CRCPAD) != 0U)
    {
      MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXNDESCRF_CPC, pTxConfig->CRCPadCtrl);
    }
  }


  if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_VLANTAG) != 0U)
  {
    /* Set Vlan Tag control */
    MODIFY_REG(dmatxdesc->DESC2, ETH_DMATXNDESCRF_VTIR, pTxConfig->VlanCtrl);
  }


  /* Mark it as First Descriptor */
  SET_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_FD);
  /* Mark it as NORMAL descriptor */
  CLEAR_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_CTXT);


  /* If source address insertion/replacement is enabled for this packet */
  if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_SAIC) != 0U)
  {
    MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXNDESCRF_SAIC, pTxConfig->SrcAddrCtrl);
  }


  /* only if the packet is split into more than one descriptors > 1 */
  while (txbuffer->next != NULL)
  {
    /* Clear the LD bit of previous descriptor */
    CLEAR_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_LD);
    __DMB();//修改!!
    /* set OWN bit of Last descriptor */
    SET_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_OWN);
    __DMB();//修改!!


    /* Increment current tx descriptor index */
    INCR_TX_DESC_INDEX(descidx, 1U);
    /* Get current descriptor address */
    dmatxdesc = (ETH_DMADescTypeDef *)dmatxdesclist->TxDesc[descidx];


    /* Clear the FD bit of new Descriptor */
    CLEAR_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_FD);


    /* Current Tx Descriptor Owned by DMA: cannot be used by the application  */
    if((READ_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_OWN) == ETH_DMATXNDESCRF_OWN) || (dmatxdesclist->PacketAddress[descidx] != NULL))
    {
      descidx = firstdescidx;
      dmatxdesc = (ETH_DMADescTypeDef *)dmatxdesclist->TxDesc[descidx];


      /* clear previous desc own bit */
      for(idx = 0; idx < descnbr; idx ++)
      {
        __DMB();//修改!!
        CLEAR_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_OWN);
        __DMB();//修改!!


        /* Increment current tx descriptor index */
        INCR_TX_DESC_INDEX(descidx, 1U);
        /* Get current descriptor address */
        dmatxdesc = (ETH_DMADescTypeDef *)dmatxdesclist->TxDesc[descidx];
      }


      return HAL_ETH_ERROR_BUSY;
    }


    descnbr += 1U;


    /* Get the next Tx buffer in the list */
    txbuffer = txbuffer->next;


    /* Set header or buffer 1 address */
    WRITE_REG(dmatxdesc->DESC0, (uint32_t)txbuffer->buffer);
    /* Set header or buffer 1 Length */
    MODIFY_REG(dmatxdesc->DESC2, ETH_DMATXNDESCRF_B1L, txbuffer->len);


    if (txbuffer->next != NULL)
    {
      /* Get the next Tx buffer in the list */
      txbuffer = txbuffer->next;
      /* Set buffer 2 address */
      WRITE_REG(dmatxdesc->DESC1, (uint32_t)txbuffer->buffer);
      /* Set buffer 2 Length */
      MODIFY_REG(dmatxdesc->DESC2, ETH_DMATXNDESCRF_B2L, (txbuffer->len << 16));
    }
    else
    {
      WRITE_REG(dmatxdesc->DESC1, 0x0);
      /* Set buffer 2 Length */
      MODIFY_REG(dmatxdesc->DESC2, ETH_DMATXNDESCRF_B2L, 0x0U);
    }


    if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_TSO) != 0U)
    {
      /* Set TCP payload length */
      MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXNDESCRF_TPL, pTxConfig->PayloadLen);
      /* Set TCP Segmentation Enabled bit */
      SET_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_TSE);
    }
    else
    {
      /* Set the packet length */
      MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXNDESCRF_FL, pTxConfig->Length);


      if(READ_BIT(pTxConfig->Attributes, ETH_TX_PACKETS_FEATURES_CSUM) != 0U)
      {
        /* Checksum Insertion Control */
        MODIFY_REG(dmatxdesc->DESC3, ETH_DMATXNDESCRF_CIC, pTxConfig->ChecksumCtrl);
      }
    }


    bd_count += 1U;


    /* Mark it as NORMAL descriptor */
    CLEAR_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_CTXT);
    
  }


  if(ItMode != ((uint32_t)RESET))
  {
    /* Set Interrupt on completion bit */
    SET_BIT(dmatxdesc->DESC2, ETH_DMATXNDESCRF_IOC);
  }
  else
  {
    /* Clear Interrupt on completion bit */
    CLEAR_BIT(dmatxdesc->DESC2, ETH_DMATXNDESCRF_IOC);
  }


  /* Mark it as LAST descriptor */
  SET_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_LD);


  __DMB();//修改!!


  /* Set Own bit For End Desc */
  SET_BIT(dmatxdesc->DESC3, ETH_DMATXNDESCRF_OWN);
  
  /* Save the current packet address to expose it to the application */
  dmatxdesclist->PacketAddress[descidx] = dmatxdesclist->CurrentPacketAddress;


  dmatxdesclist->CurTxDesc = descidx;


  /* disable the interrupt */
  //__disable_irq();
  //我最看不慣的就是關(guān)中斷!!
  //dmatxdesclist->BuffersInUse += bd_count + 1U;


  /* Enable interrupts back */
  //__enable_irq();




  /* Return function status */
  return HAL_ETH_ERROR_NONE;
}




HAL_StatusTypeDef HAL_ETH_Transmit(ETH_HandleTypeDef *heth, ETH_TxPacketConfig *pTxConfig, uint32_t Timeout)
{
  uint32_t tickstart;
  const ETH_DMADescTypeDef *dmatxdesc;


  if(pTxConfig == NULL)
  {
    heth->ErrorCode |= HAL_ETH_ERROR_PARAM;
    return HAL_ERROR;
  }


  if(heth->gState == HAL_ETH_STATE_READY)
  {
    /* Config DMA Tx descriptor by Tx Packet info */
    if (ETH_Prepare_Tx_Descriptors(heth, pTxConfig, 0) != HAL_ETH_ERROR_NONE)
    {
      /* Set the ETH error code */
      heth->ErrorCode |= HAL_ETH_ERROR_BUSY;
      return HAL_ERROR;
    }


    dmatxdesc = (ETH_DMADescTypeDef *)(&heth->TxDescList)->TxDesc[heth->TxDescList.CurTxDesc];


    /* Incr current tx desc index */
    INCR_TX_DESC_INDEX(heth->TxDescList.CurTxDesc, 1U);


    /* Start transmission */
    /* issue a poll command to Tx DMA by writing address of next immediate free descriptor */
    //WRITE_REG(heth->Instance->DMACTDTPR, (uint32_t)(heth->TxDescList.TxDesc[heth->TxDescList.CurTxDesc]));
    __DMB();//修改!!
    WRITE_REG(heth->Instance->DMACTDTPR, ((uint32_t)(heth->Init.TxDesc + (uint32_t)(ETH_TX_DESC_CNT - 1))));


    tickstart = HAL_GetTick();


    /* Wait for data to be transmitted or timeout occurred */
    while((dmatxdesc->DESC3 & ETH_DMATXNDESCWBF_OWN) != (uint32_t)RESET)
    {
      if((heth->Instance->DMACSR & ETH_DMACSR_FBE) != (uint32_t)RESET)
      {
        heth->ErrorCode |= HAL_ETH_ERROR_DMA;
        heth->DMAErrorCode = heth->Instance->DMACSR;
        /* Set ETH HAL State to Ready */
        heth->gState = HAL_ETH_STATE_ERROR;
        /* Return function status */
        return HAL_ERROR;
      }


      /* Check for the Timeout */
      if(Timeout != HAL_MAX_DELAY)
      {
        if(((HAL_GetTick() - tickstart ) > Timeout) || (Timeout == 0U))
        {
          heth->ErrorCode |= HAL_ETH_ERROR_TIMEOUT;
          heth->gState = HAL_ETH_STATE_ERROR;
          return HAL_ERROR;
        }
      }
    }


    /* Return function status */
    return HAL_OK;
  }
  else
  {
    return HAL_ERROR;
  }
}


/**
  * @brief  Sends an Ethernet Packet in interrupt mode.
  * @param  heth: pointer to a ETH_HandleTypeDef structure that contains
  *         the configuration information for ETHERNET module
  * @param  pTxConfig: Hold the configuration of packet to be transmitted
  * @retval HAL status
  */
HAL_StatusTypeDef HAL_ETH_Transmit_IT(ETH_HandleTypeDef *heth, ETH_TxPacketConfig *pTxConfig)
{
  if(pTxConfig == NULL)
  {
    heth->ErrorCode |= HAL_ETH_ERROR_PARAM;
    return HAL_ERROR;
  }


  if(heth->gState == HAL_ETH_STATE_READY)
  {
    /* Config DMA Tx descriptor by Tx Packet info */
    if (ETH_Prepare_Tx_Descriptors(heth, pTxConfig, 1) != HAL_ETH_ERROR_NONE)
    {
      heth->ErrorCode |= HAL_ETH_ERROR_BUSY;
      return HAL_ERROR;
    }


    /* Incr current tx desc index */
    INCR_TX_DESC_INDEX(heth->TxDescList.CurTxDesc, 1U);


    __DMB();//修改!!


    /* Start transmission */
    /* issue a poll command to Tx DMA by writing address of next immediate free descriptor */
    //WRITE_REG(heth->Instance->DMACTDTPR, (uint32_t)(heth->TxDescList.TxDesc[heth->TxDescList.CurTxDesc]));
    WRITE_REG(heth->Instance->DMACTDTPR, (uint32_t)(heth->TxDescList.TxDesc[ETH_TX_DESC_CNT-1]));


    return HAL_OK;


  }
  else
  {
    return HAL_ERROR;
  }
}

接收的修改

接收相關(guān)的函數(shù)有2個(gè)被修改

uint8_t HAL_ETH_IsRxDataAvailable(ETH_HandleTypeDef *heth)
{
  ETH_RxDescListTypeDef *dmarxdesclist = &heth->RxDescList;
  uint32_t descidx = dmarxdesclist->CurRxDesc;
  ETH_DMADescTypeDef *dmarxdesc = (ETH_DMADescTypeDef *)dmarxdesclist->RxDesc[descidx];
  uint32_t descscancnt = 0;
  uint32_t appdesccnt = 0, firstappdescidx = 0;


  if(dmarxdesclist->AppDescNbr != 0U)
  {
    /* data already received by not yet processed*/
    return 0;
  }


  /* Check if descriptor is not owned by DMA */
  while((READ_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCWBF_OWN) == (uint32_t)RESET) && (descscancnt < (uint32_t)ETH_RX_DESC_CNT))
  {
    descscancnt++;


    /* Check if last descriptor */
    if(READ_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCWBF_LD) != (uint32_t)RESET)
    {
      /* Increment the number of descriptors to be passed to the application */
      appdesccnt += 1U;


      if(appdesccnt == 1U)
      {
        WRITE_REG(firstappdescidx, descidx);
      }


      /* Increment current rx descriptor index */
      INCR_RX_DESC_INDEX(descidx, 1U);


      /* Check for Context descriptor */
      /* Get current descriptor address */
      dmarxdesc = (ETH_DMADescTypeDef *)dmarxdesclist->RxDesc[descidx];


      if(READ_BIT(dmarxdesc->DESC3,  ETH_DMARXNDESCWBF_OWN)  == (uint32_t)RESET)
      {
        if(READ_BIT(dmarxdesc->DESC3,  ETH_DMARXNDESCWBF_CTXT)  != (uint32_t)RESET)
        {
          /* Increment the number of descriptors to be passed to the application */
          dmarxdesclist->AppContextDesc = 1;
          /* Increment current rx descriptor index */
          INCR_RX_DESC_INDEX(descidx, 1U);
        }
      }
      /* Fill information to Rx descriptors list */
      dmarxdesclist->CurRxDesc = descidx;
      dmarxdesclist->FirstAppDesc = firstappdescidx;
      dmarxdesclist->AppDescNbr = appdesccnt;


      /* Return function status */
      return 1;
    }
    /* Check if first descriptor */
    else if(READ_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCWBF_FD) != (uint32_t)RESET)
    {
      WRITE_REG(firstappdescidx, descidx);
      /* Increment the number of descriptors to be passed to the application */
      appdesccnt = 1U;


      /* Increment current rx descriptor index */
      INCR_RX_DESC_INDEX(descidx, 1U);
      /* Get current descriptor address */
      dmarxdesc = (ETH_DMADescTypeDef *)dmarxdesclist->RxDesc[descidx];
    }
    /* It should be an intermediate descriptor */
    else
    {
      /* Increment the number of descriptors to be passed to the application */
      appdesccnt += 1U;


      /* Increment current rx descriptor index */
      INCR_RX_DESC_INDEX(descidx, 1U);
      /* Get current descriptor address */
      dmarxdesc = (ETH_DMADescTypeDef *)dmarxdesclist->RxDesc[descidx];
    }
  }


  /* Build Descriptors if an incomplete Packet is received */
  if(appdesccnt > 0U)
  {
    dmarxdesclist->CurRxDesc = descidx;
    dmarxdesclist->FirstAppDesc = firstappdescidx;
    descidx = firstappdescidx;
    dmarxdesc = (ETH_DMADescTypeDef *)dmarxdesclist->RxDesc[descidx];


    for(descscancnt = 0; descscancnt < appdesccnt; descscancnt++)
    {
      WRITE_REG(dmarxdesc->DESC0, dmarxdesc->BackupAddr0);
      WRITE_REG(dmarxdesc->DESC3, ETH_DMARXNDESCRF_BUF1V);


      if (READ_REG(dmarxdesc->BackupAddr1) != ((uint32_t)RESET))
      {
        WRITE_REG(dmarxdesc->DESC2, dmarxdesc->BackupAddr1);
        SET_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCRF_BUF2V);
      }


      SET_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCRF_OWN);


      if(dmarxdesclist->ItMode != ((uint32_t)RESET))
      {
        SET_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCRF_IOC);
      }
      if(descscancnt < (appdesccnt - 1U))
      {
        /* Increment rx descriptor index */
        INCR_RX_DESC_INDEX(descidx, 1U);
        /* Get descriptor address */
        dmarxdesc = (ETH_DMADescTypeDef *)dmarxdesclist->RxDesc[descidx];
      }
    }


    /* Set the Tail pointer address to the last rx descriptor hold by the app */
    //WRITE_REG(heth->Instance->DMACRDTPR, (uint32_t)dmarxdesc);
  }


  /* Fill information to Rx descriptors list: No received Packet */
  dmarxdesclist->AppDescNbr = 0U;


  return 0;
}


HAL_StatusTypeDef HAL_ETH_BuildRxDescriptors(ETH_HandleTypeDef *heth)
{
  ETH_RxDescListTypeDef *dmarxdesclist = &heth->RxDescList;
  uint32_t descindex = dmarxdesclist->FirstAppDesc;
  __IO ETH_DMADescTypeDef *dmarxdesc = (ETH_DMADescTypeDef *)dmarxdesclist->RxDesc[descindex];
  uint32_t totalappdescnbr = dmarxdesclist->AppDescNbr;
  uint32_t descscan;


  if(dmarxdesclist->AppDescNbr == 0U)
  {
    /* No Rx descriptors to build */
    return HAL_ERROR;
  }


  if(dmarxdesclist->AppContextDesc != 0U)
  {
    /* A context descriptor is available */
    totalappdescnbr += 1U;
  }


  for(descscan =0; descscan < totalappdescnbr; descscan++)
  {
    WRITE_REG(dmarxdesc->DESC0, dmarxdesc->BackupAddr0);
    WRITE_REG(dmarxdesc->DESC3, ETH_DMARXNDESCRF_BUF1V);


    if (READ_REG(dmarxdesc->BackupAddr1) != 0U)
    {
      WRITE_REG(dmarxdesc->DESC2, dmarxdesc->BackupAddr1);
      SET_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCRF_BUF2V);
    }


    if(dmarxdesclist->ItMode != 0U){
      SET_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCRF_IOC);
    }


    __DMB();//修改!!
    SET_BIT(dmarxdesc->DESC3, ETH_DMARXNDESCRF_OWN);


    if(descscan < (totalappdescnbr - 1U))
    {
      /* Increment rx descriptor index */
      INCR_RX_DESC_INDEX(descindex, 1U);
      /* Get descriptor address */
      dmarxdesc = (ETH_DMADescTypeDef *)dmarxdesclist->RxDesc[descindex];
    }
  }


  __DMB();//修改!!
  /* Set the Tail pointer address to the last rx descriptor hold by the app */
  //WRITE_REG(heth->Instance->DMACRDTPR, (uint32_t)dmarxdesc);//修改!!
  WRITE_REG(heth->Instance->DMACRDTPR, ((uint32_t)(heth->Init.RxDesc + (uint32_t)(ETH_RX_DESC_CNT - 1))));


  /* reset the Application desc number */
  WRITE_REG(dmarxdesclist->AppDescNbr, 0);


  /*  reset the application context descriptor */
  WRITE_REG(heth->RxDescList.AppContextDesc, 0);


  return HAL_OK;
}

其他修改

其實(shí)下面的修改無(wú)關(guān)緊要，因?yàn)樗鼤?huì)在后面的傳輸中被修正，但強(qiáng)迫癥不能忍啊。

static void ETH_DMATxDescListInit(ETH_HandleTypeDef *heth)
{
  ETH_DMADescTypeDef *dmatxdesc;
  uint32_t i;


  /* Fill each DMATxDesc descriptor with the right values */
  for(i=0; i < (uint32_t)ETH_TX_DESC_CNT; i++)
  {
    dmatxdesc = heth->Init.TxDesc + i;


    WRITE_REG(dmatxdesc->DESC0, 0x0);
    WRITE_REG(dmatxdesc->DESC1, 0x0);
    WRITE_REG(dmatxdesc->DESC2, 0x0);
    WRITE_REG(dmatxdesc->DESC3, 0x0);


    WRITE_REG(heth->TxDescList.TxDesc[i], (uint32_t)dmatxdesc);
  }


  heth->TxDescList.CurTxDesc = 0;


  /* Set Transmit Descriptor Ring Length */
  WRITE_REG(heth->Instance->DMACTDRLR, (ETH_TX_DESC_CNT -1));


  /* Set Transmit Descriptor List Address */
  WRITE_REG(heth->Instance->DMACTDLAR, (uint32_t) heth->Init.TxDesc);


  /* Set Transmit Descriptor Tail pointer *///修改!!
  WRITE_REG(heth->Instance->DMACTDTPR, ((uint32_t)(heth->Init.TxDesc + (uint32_t)(ETH_TX_DESC_CNT - 1))));//修改!!
}


/**
  * @brief  Initializes the DMA Rx descriptors in chain mode.
  *         called by HAL_ETH_Init() API.
  * @param  heth: pointer to a ETH_HandleTypeDef structure that contains
  *         the configuration information for ETHERNET module
  * @retval None
  */
static void ETH_DMARxDescListInit(ETH_HandleTypeDef *heth)
{
  ETH_DMADescTypeDef *dmarxdesc;
  uint32_t i;


  for(i = 0; i < (uint32_t)ETH_RX_DESC_CNT; i++)
  {
    dmarxdesc =  heth->Init.RxDesc + i;


    WRITE_REG(dmarxdesc->DESC0, 0x0);
    WRITE_REG(dmarxdesc->DESC1, 0x0);
    WRITE_REG(dmarxdesc->DESC2, 0x0);
    WRITE_REG(dmarxdesc->DESC3, 0x0);
    WRITE_REG(dmarxdesc->BackupAddr0, 0x0);
    WRITE_REG(dmarxdesc->BackupAddr1, 0x0);


    /* Set Rx descritors addresses */
    WRITE_REG(heth->RxDescList.RxDesc[i], (uint32_t)dmarxdesc);
  }


  WRITE_REG(heth->RxDescList.CurRxDesc, 0);
  WRITE_REG(heth->RxDescList.FirstAppDesc, 0);
  WRITE_REG(heth->RxDescList.AppDescNbr, 0);
  WRITE_REG(heth->RxDescList.ItMode, 0);
  WRITE_REG(heth->RxDescList.AppContextDesc, 0);


  /* Set Receive Descriptor Ring Length */
  WRITE_REG(heth->Instance->DMACRDRLR, ((uint32_t)(ETH_RX_DESC_CNT - 1)));


  /* Set Receive Descriptor List Address */
  WRITE_REG(heth->Instance->DMACRDLAR, (uint32_t) heth->Init.RxDesc);


  /* Set Receive Descriptor Tail pointer Address *///修改!!
  WRITE_REG(heth->Instance->DMACRDTPR, ((uint32_t)(heth->Init.RxDesc + (uint32_t)(ETH_RX_DESC_CNT - 1))));//修改!!
}