Hi,
I have been debugging network issues when running an EFI Application that uses the EFI Simple Network protocol on an i.MX6 machine (FEC).
The symptom is that u-boot's (FEC) internal RX ring index is reset to 0, while the controller is still at idx 3 (or something else). This is caused by the following circumstances:
The Simple Network protocol offers methods like Start(), Stop(), Initialize(), Shutdown(), Reset(). Also the protocol has a state. The states are Stopped, Started, Initialized. The transition is as follows:
Stopped ---Start()---> Started ---Initialize()--> Initialized
Start() does some initialization, Initialize() allocates the TX/RX descriptors and actually kicks off the network engine.
So far, only Initialize() is implemented in our u-boot interface, and it calls eth_init() which in the end calls fec_init(). Our network state is _always_ Started. This means that EFI Applications see that that the state is Started and then call Initialize() to start the actual network traffic. There is no call to Stop()/Shutdown()/Reset() as it's supposed to be in a sane state.
In my case the FEC is already initialized since I booted using network and the RX desc index is already non-zero. Now the EFI Application sees that the state is Started, calls Initialize() which makes u-boot call eth_init() which then calls fec_init().
fec_init() does not reset the controller so that the controller-internal RX desc index is not reset to zero. fec_init() calls fec_open() which then resets the driver-internal RX desc index to zero. Now they are out of sync, boom.
This means that fec_init() without a previous fec_halt() breaks the whole network if it was already running. The Designware driver as used by some sunxi platforms does a reset of the controller in the init function. Maybe calling fec_halt() at the start of fec_init() could be a possible solution?
Patrick
diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c index ff7ad91116..ba8bd9920d 100644 --- a/drivers/net/fec_mxc.c +++ b/drivers/net/fec_mxc.c @@ -522,6 +522,12 @@ static int fec_open(struct eth_device *edev) return 0; }
+#ifdef CONFIG_DM_ETH +static void fecmxc_halt(struct udevice *dev); +#else +static void fec_halt(struct eth_device *dev); +#endif + #ifdef CONFIG_DM_ETH static int fecmxc_init(struct udevice *dev) #else @@ -537,6 +543,15 @@ static int fec_init(struct eth_device *dev, bd_t *bd) u8 *i; ulong addr;
+#ifdef CONFIG_DM_ETH + fecmxc_halt(dev); +#else + fec_halt(dev); +#endif + + writel(~FEC_TCNTRL_GTS & readl(&fec->eth->x_cntrl), + &fec->eth->x_cntrl); + /* Initialize MAC address */ #ifdef CONFIG_DM_ETH fecmxc_set_hwaddr(dev); @@ -825,19 +840,12 @@ static int fec_recv(struct eth_device *dev) } if (ievent & FEC_IEVENT_HBERR) { /* Heartbeat error */ - writel(0x00000001 | readl(&fec->eth->x_cntrl), + writel(FEC_TCNTRL_GTS | readl(&fec->eth->x_cntrl), &fec->eth->x_cntrl); } if (ievent & FEC_IEVENT_GRA) { /* Graceful stop complete */ - if (readl(&fec->eth->x_cntrl) & 0x00000001) { -#ifdef CONFIG_DM_ETH - fecmxc_halt(dev); -#else - fec_halt(dev); -#endif - writel(~0x00000001 & readl(&fec->eth->x_cntrl), - &fec->eth->x_cntrl); + if (readl(&fec->eth->x_cntrl) & FEC_TCNTRL_GTS) { #ifdef CONFIG_DM_ETH fecmxc_init(dev); #else