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SAMA5 EMAC: Need to pace RX and TX because and RX can result in a TX; Process TX interrupt events before TX interrupt events for the same reason

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This commit is contained in:
Gregory Nutt 2013-09-25 14:22:35 -06:00
parent d53a0189f7
commit 5f4682c874
1 changed files with 91 additions and 60 deletions
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149
arch/arm/src/sama5/sam_emac.c
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@ -323,7 +323,7 @@ static uint8_t g_rxbuffer[CONFIG_SAMA5_EMAC_NRXBUFFERS * EMAC_RX_UNITSIZE]
/* Register operations ******************************************************/
#if defined(CONFIG_SAMA5_EMAC_REGDEBUG) && defined(CONFIG_DEBUG)
static bool sasm_checkreg(struct sam_emac_s *priv, bool wr,
static bool sam_checkreg(struct sam_emac_s *priv, bool wr,
uint32_t regval, uintptr_t address);
static uint32_t sam_getreg(struct sam_emac_s *priv, uintptr_t addr);
static void sam_putreg(struct sam_emac_s *priv, uintptr_t addr, uint32_t val);
@ -763,6 +763,26 @@ static int sam_transmit(struct sam_emac_s *priv)
(void)wd_start(priv->txtimeout, SAM_TXTIMEOUT, sam_txtimeout, 1,
(uint32_t)priv);
/* Set d_len to zero meaning that the d_buf[] packet buffer is again
* available.
*/
dev->d_len = 0;
/* If we have no more available TX descriptors, then we must disable the
* RCOMP interrupt to stop further RX processing. Why? Because EACH RX
* packet that is dispatch is also an opportunity to replay with the a TX
* packet. So, if we cannot handle an RX packet replay, then we disable
* all RX packet processing.
*/
if (sam_txfree(priv) < 1)
{
nllvdbg("Disabling RX interrupts\n");
sam_putreg(priv, SAM_EMAC_IDR, EMAC_INT_RCOMP);
}
return OK;
}
@ -1234,8 +1254,17 @@ static void sam_txdone(struct sam_emac_s *priv)
if (++priv->txtail >= CONFIG_SAMA5_EMAC_NTXBUFFERS)
{
/* Wrap to the beginning of the TX descriptor list */
priv->txtail = 0;
}
/* At least one TX descriptor is available. Re-enable RX interrupts.
* RX interrupts may previously have been disabled when we ran out of
* TX desciptors (see commits in sam_transmit()).
*/
sam_putreg(priv, SAM_EMAC_IER, EMAC_INT_RCOMP);
}
/* Then poll uIP for new XMIT data */
@ -1279,61 +1308,9 @@ static int sam_emac_interrupt(int irq, void *context)
pending = isr & ~(imr | 0xffc300);
nllvdbg("isr: %08x pending: %08x\n", isr, pending);
/* Check for the receipt of an RX packet.
*
* RXCOMP indicates that a packet has been received and stored in memory.
* The RXCOMP bit is cleared whent he interrupt status register was read.
* RSR:REC indicates that one or more frames have been received and placed
* in memory. This indication is cleared by writing a one to this bit.
*/
if ((pending & EMAC_INT_RCOMP) != 0 || (rsr & EMAC_RSR_REC) != 0)
{
clrbits = EMAC_RSR_REC;
/* Check for Receive Overrun.
*
* RSR:RXOVR will be set if the RX FIFO is not able to store the
* receive frame due to a FIFO overflow, or if the receive status
* was not taken at the end of the frame. This bit is also set in
* DMA packet buffer mode if the packet buffer overflows. For DMA
* operation, the buffer will be recovered if an overrun occurs. This
* bit is cleared when set to 1.
*/
if ((rsr & EMAC_RSR_OVR) != 0)
{
nlldbg("ERROR: Receiver overrun RSR: %08x\n", rsr);
clrbits |= EMAC_RSR_OVR;
}
/* Check for buffer not available (BNA)
*
* RSR:BNA means that an attempt was made to get a new buffer and the
* pointer indicated that it was owned by the processor. The DMA will
* reread the pointer each time an end of frame is received until a
* valid pointer is found. This bit is set following each descriptor
* read attempt that fails, even if consecutive pointers are
* unsuccessful and software has in the mean time cleared the status
* flag. Cleared by writing a one to this bit.
*/
if ((rsr & EMAC_RSR_BNA) != 0)
{
nlldbg("ERROR: Buffer not available RSR: %08x\n", rsr);
clrbits |= EMAC_RSR_BNA;
}
/* Clear status */
sam_putreg(priv, SAM_EMAC_RSR, clrbits);
/* Handle the received packet */
sam_receive(priv);
}
/* Check for the completion of a transmission
/* Check for the completion of a transmission. This should be done before
* checking for received data (because receiving can cause another transmission
* before we had a chance to handle the last one).
*
* ISR:TCOMP is set when a frame has been transmitted. Cleared on read.
* TSR:COMP is set when a frame has been transmitted. Cleared by writing a
@ -1402,6 +1379,60 @@ static int sam_emac_interrupt(int irq, void *context)
sam_txdone(priv);
}
/* Check for the receipt of an RX packet.
*
* RXCOMP indicates that a packet has been received and stored in memory.
* The RXCOMP bit is cleared whent he interrupt status register was read.
* RSR:REC indicates that one or more frames have been received and placed
* in memory. This indication is cleared by writing a one to this bit.
*/
if ((pending & EMAC_INT_RCOMP) != 0 || (rsr & EMAC_RSR_REC) != 0)
{
clrbits = EMAC_RSR_REC;
/* Check for Receive Overrun.
*
* RSR:RXOVR will be set if the RX FIFO is not able to store the
* receive frame due to a FIFO overflow, or if the receive status
* was not taken at the end of the frame. This bit is also set in
* DMA packet buffer mode if the packet buffer overflows. For DMA
* operation, the buffer will be recovered if an overrun occurs. This
* bit is cleared when set to 1.
*/
if ((rsr & EMAC_RSR_OVR) != 0)
{
nlldbg("ERROR: Receiver overrun RSR: %08x\n", rsr);
clrbits |= EMAC_RSR_OVR;
}
/* Check for buffer not available (BNA)
*
* RSR:BNA means that an attempt was made to get a new buffer and the
* pointer indicated that it was owned by the processor. The DMA will
* reread the pointer each time an end of frame is received until a
* valid pointer is found. This bit is set following each descriptor
* read attempt that fails, even if consecutive pointers are
* unsuccessful and software has in the mean time cleared the status
* flag. Cleared by writing a one to this bit.
*/
if ((rsr & EMAC_RSR_BNA) != 0)
{
nlldbg("ERROR: Buffer not available RSR: %08x\n", rsr);
clrbits |= EMAC_RSR_BNA;
}
/* Clear status */
sam_putreg(priv, SAM_EMAC_RSR, clrbits);
/* Handle the received packet */
sam_receive(priv);
}
#ifdef CONFIG_DEBUG_NET
/* Check for PAUSE Frame recieved (PFRE).
*
@ -2525,7 +2556,7 @@ static void sam_txreset(struct sam_emac_s *priv)
{
bufaddr = (uint32_t)(&(txbuffer[ndx * EMAC_TX_UNITSIZE]));
/* Set the buffer address and mark the descriptor as used */
/* Set the buffer address and mark the descriptor as in used by firmware */
physaddr = sam_physramaddr(bufaddr);
txdesc[ndx].addr = physaddr;
@ -2539,7 +2570,7 @@ static void sam_txreset(struct sam_emac_s *priv)
/* Set the Transmit Buffer Queue Pointer Register */
physaddr = sam_physramaddr((uint32_t)txdesc);
physaddr = sam_physramaddr((uintptr_t)txdesc);
sam_putreg(priv, SAM_EMAC_TBQP, physaddr);
}
@ -2603,7 +2634,7 @@ static void sam_rxreset(struct sam_emac_s *priv)
/* Set the Receive Buffer Queue Pointer Register */
physaddr = sam_physramaddr((uint32_t)rxdesc);
physaddr = sam_physramaddr((uintptr_t)rxdesc);
sam_putreg(priv, SAM_EMAC_RBQP, physaddr);
}