Ethernet PHY Status -Link Status bit is not set even if link is established and active.

Hello Aigars

No it does work after plug-unplug-plug

Regards
Amit

Strange... what I am missing???
Did you change something in original tiva-tm4c129.c file?
Have you any idea why it's not working for me?

Hello Aigans

Did you try a known example like qs_iot on a EK-TM4C1294XL to see if it works for you?

Regards
Amit

I tried today qs_iot example and it works as expected. Bit is set/cleared on every cable plug/unplug event.

But my project based on the same code - not.

What else could cause such behavior?

I compared result values in tivaif_process_phy_interrupt(struct netif *psNetif)

/* Read the PHY interrupt status. This clears all interrupt sources.
* Note that we are only enabling sources in EPHY_MISR1 so we don't
* read EPHY_MISR2.
*/

ui16Val = EMACPHYRead(EMAC0_BASE, PHY_PHYS_ADDR, EPHY_MISR1);

and

/* Read the current PHY status. */

ui16Status = EMACPHYRead(EMAC0_BASE, PHY_PHYS_ADDR, EPHY_STS);

function and they are  the same in all cases except one bit - link status.

In my project it is set only once per session.

/////// NON WORKING my project//////
1. PLUG-IN
ui16Val = 0x243C
ui16Status = 0x1115 // <-- Here bit 0 has set correctly

2. PLUG-OUT
ui16Val = 0x223C
ui16Status = 0x1912

3. PLUG-IN
ui16Val = 0x243C
ui16Status = 0x1914 // <-- Here !!! bit 0 has never set again !!!

4. PLUG-OUT
ui16Val = 0x223C
ui16Status = 0x1912

/////// WORKING qs_iot example //////
1. PLUG-IN
ui16Val = 0x243C
ui16Status = 0x1115

2. PLUG-OUT
ui16Val = 0x223C
ui16Status = 0x1912

3. PLUG-IN
ui16Val = 0x243C
ui16Status = 0x1915

4. PLUG-OUT
ui16Val = 0x223C
ui16Status = 0x1912

 

Have you any idea why?

Hello Aigars

Is the configuration of EMAC and PHY the same between the two codes?

Regards
Amit

Did not compare, but both projects use the same files for lwip.
Fortunately I found workaround for my problem.
I found that if I force read Ethernet PHY Basic Mode Status - MR1 (EPHYBMSR), address
0x001 on event when cable is unplugged helps to fix this behavior.
May be you could explain why, but I am happy just with this fix.


Here is modified routine that fix this behavior:


void
tivaif_process_phy_interrupt(struct netif *psNetif)
{
uint16_t ui16Val, ui16Status;
uint32_t ui32Config, ui32Mode, ui32RxMaxFrameSize;

/* Read the PHY interrupt status. This clears all interrupt sources.
* Note that we are only enabling sources in EPHY_MISR1 so we don't
* read EPHY_MISR2.
*/
ui16Val = EMACPHYRead(EMAC0_BASE, PHY_PHYS_ADDR, EPHY_MISR1);

/* Read the current PHY status. */
ui16Status = EMACPHYRead(EMAC0_BASE, PHY_PHYS_ADDR, EPHY_STS);

/* Has the link status changed? */
if(ui16Val & EPHY_MISR1_LINKSTAT)
{

/* Is link up or down now? */
if(ui16Status & EPHY_STS_LINK)
{

/* Tell lwIP the link is up. */
#if NO_SYS
netif_set_link_up(psNetif);
#else
tcpip_callback((tcpip_callback_fn)netif_set_link_up, psNetif);
#endif

/* In this case we drop through since we may need to reconfigure
* the MAC depending upon the speed and half/fui32l-duplex settings.
*/
}
else
{
// HERE IS MY FIX
/* fix link status bit error by reading Basic Mode Status register*/
EMACPHYRead(EMAC0_BASE, PHY_PHYS_ADDR, EPHY_BMSR);
// END OF MY FIX

/* Tell lwIP the link is down */
#if NO_SYS
netif_set_link_down(psNetif);
#else
tcpip_callback((tcpip_callback_fn)netif_set_link_down, psNetif);
#endif
}
}

/* Has the speed or duplex status changed? */
if(ui16Val & (EPHY_MISR1_SPEED | EPHY_MISR1_SPEED | EPHY_MISR1_ANC))
{
/* Get the current MAC configuration. */
EMACConfigGet(EMAC0_BASE, &ui32Config, &ui32Mode,
&ui32RxMaxFrameSize);

/* What speed is the interface running at now?
*/
if(ui16Status & EPHY_STS_SPEED)
{
/* 10Mbps is selected */
ui32Config &= ~EMAC_CONFIG_100MBPS;
}
else
{
/* 100Mbps is selected */
ui32Config |= EMAC_CONFIG_100MBPS;
}

/* Are we in fui32l- or half-duplex mode? */
if(ui16Status & EPHY_STS_DUPLEX)
{
/* Fui32l duplex. */
ui32Config |= EMAC_CONFIG_FULL_DUPLEX;
}
else
{
/* Half duplex. */
ui32Config &= ~EMAC_CONFIG_FULL_DUPLEX;
}

/* Reconfigure the MAC */
EMACConfigSet(EMAC0_BASE, ui32Config, ui32Mode, ui32RxMaxFrameSize);
}
}


BTW the value of EPHY_BMSR when read is 0x7849

Hello Aigars,

They may use the same set of file, but not all function calls may be used as there are if-else conditions. I would have first checked the value of the registers as a comparison point.

Regards
Amit