[PATCH 1/2] r8169: Rx FIFO overflow fixes.

From: Francois Romieu
Date: Mon Dec 05 2011 - 01:37:45 EST


Realtek has specified that the post 8168c gigabit chips and the post
8105e fast ethernet chips recover automatically from a Rx FIFO overflow.
The driver does not need to clear the RxFIFOOver bit of IntrStatus and
it should rather avoid messing it.

The implementation deserves some explanation:
1. events outside of the intr_event bit mask are now ignored. It enforces
a no-processing policy for the events that either should not be there
or should be ignored.

2. RxFIFOOver was already ignored in rtl_cfg_infos[RTL_CFG_1] for the
whole 8168 line of chips with two exceptions:
- RTL_GIGA_MAC_VER_22 since b5ba6d12bdac21bc0620a5089e0f24e362645efd
("use RxFIFO overflow workaround for 8168c chipset.").
This one should now be correctly handled.
- RTL_GIGA_MAC_VER_11 (8168b) which requires a different Rx FIFO
overflow processing.

Though it does not conform to Realtek suggestion above, the updated
driver includes no change for RTL_GIGA_MAC_VER_12 and RTL_GIGA_MAC_VER_17.
Both are 8168b. RTL_GIGA_MAC_VER_12 is common and a bit old so I'd rather
wait for experimental evidence that the change suggested by Realtek really
helps or does not hurt in unexpected ways.

Removed case statements in rtl8169_interrupt are only 8168 relevant.

3. RxFIFOOver is masked for post 8105e 810x chips, namely the sole 8105e
(RTL_GIGA_MAC_VER_30) itself.

Signed-off-by: Francois Romieu <romieu@xxxxxxxxxxxxx>
Cc: hayeswang <hayeswang@xxxxxxxxxxx>
---

Gerd, can you add your Tested-by: to this patch ? Thanks.

drivers/net/ethernet/realtek/r8169.c | 42 +++++++++++++--------------------
1 files changed, 17 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 6f06aa1..7a1e3a6 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -1183,11 +1183,13 @@ static u8 rtl8168d_efuse_read(void __iomem *ioaddr, int reg_addr)
return value;
}

-static void rtl8169_irq_mask_and_ack(void __iomem *ioaddr)
+static void rtl8169_irq_mask_and_ack(struct rtl8169_private *tp)
{
- RTL_W16(IntrMask, 0x0000);
+ void __iomem *ioaddr = tp->mmio_addr;

- RTL_W16(IntrStatus, 0xffff);
+ RTL_W16(IntrMask, 0x0000);
+ RTL_W16(IntrStatus, tp->intr_event);
+ RTL_R8(ChipCmd);
}

static unsigned int rtl8169_tbi_reset_pending(struct rtl8169_private *tp)
@@ -4339,7 +4341,7 @@ static void rtl8169_hw_reset(struct rtl8169_private *tp)
void __iomem *ioaddr = tp->mmio_addr;

/* Disable interrupts */
- rtl8169_irq_mask_and_ack(ioaddr);
+ rtl8169_irq_mask_and_ack(tp);

rtl_rx_close(tp);

@@ -4885,8 +4887,7 @@ static void rtl_hw_start_8168(struct net_device *dev)
RTL_W16(IntrMitigate, 0x5151);

/* Work around for RxFIFO overflow. */
- if (tp->mac_version == RTL_GIGA_MAC_VER_11 ||
- tp->mac_version == RTL_GIGA_MAC_VER_22) {
+ if (tp->mac_version == RTL_GIGA_MAC_VER_11) {
tp->intr_event |= RxFIFOOver | PCSTimeout;
tp->intr_event &= ~RxOverflow;
}
@@ -5076,6 +5077,11 @@ static void rtl_hw_start_8101(struct net_device *dev)
void __iomem *ioaddr = tp->mmio_addr;
struct pci_dev *pdev = tp->pci_dev;

+ if (tp->mac_version >= RTL_GIGA_MAC_VER_30) {
+ tp->intr_event &= ~RxFIFOOver;
+ tp->napi_event &= ~RxFIFOOver;
+ }
+
if (tp->mac_version == RTL_GIGA_MAC_VER_13 ||
tp->mac_version == RTL_GIGA_MAC_VER_16) {
int cap = pci_pcie_cap(pdev);
@@ -5342,7 +5348,7 @@ static void rtl8169_wait_for_quiescence(struct net_device *dev)
/* Wait for any pending NAPI task to complete */
napi_disable(&tp->napi);

- rtl8169_irq_mask_and_ack(ioaddr);
+ rtl8169_irq_mask_and_ack(tp);

tp->intr_mask = 0xffff;
RTL_W16(IntrMask, tp->intr_event);
@@ -5804,6 +5810,10 @@ static irqreturn_t rtl8169_interrupt(int irq, void *dev_instance)
*/
status = RTL_R16(IntrStatus);
while (status && status != 0xffff) {
+ status &= tp->intr_event;
+ if (!status)
+ break;
+
handled = 1;

/* Handle all of the error cases first. These will reset
@@ -5818,27 +5828,9 @@ static irqreturn_t rtl8169_interrupt(int irq, void *dev_instance)
switch (tp->mac_version) {
/* Work around for rx fifo overflow */
case RTL_GIGA_MAC_VER_11:
- case RTL_GIGA_MAC_VER_22:
- case RTL_GIGA_MAC_VER_26:
netif_stop_queue(dev);
rtl8169_tx_timeout(dev);
goto done;
- /* Testers needed. */
- case RTL_GIGA_MAC_VER_17:
- case RTL_GIGA_MAC_VER_19:
- case RTL_GIGA_MAC_VER_20:
- case RTL_GIGA_MAC_VER_21:
- case RTL_GIGA_MAC_VER_23:
- case RTL_GIGA_MAC_VER_24:
- case RTL_GIGA_MAC_VER_27:
- case RTL_GIGA_MAC_VER_28:
- case RTL_GIGA_MAC_VER_31:
- /* Experimental science. Pktgen proof. */
- case RTL_GIGA_MAC_VER_12:
- case RTL_GIGA_MAC_VER_25:
- if (status == RxFIFOOver)
- goto done;
- break;
default:
break;
}
--
1.7.6.4

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