[Commit-gnuradio] r10634 - gnuradio/trunk/usrp2/firmware/lib

[eb]

Author: eb
Date: 2009-03-18 14:00:41 -0600 (Wed, 18 Mar 2009)
New Revision: 10634

Modified:
   gnuradio/trunk/usrp2/firmware/lib/ethernet.c
   gnuradio/trunk/usrp2/firmware/lib/ethernet.h
Log:
Fixed ticket:339 (ethernet capability advertisement).  We now
advertise that we only handle 1000BASE-T, and that we want to send
PAUSE frames, but not receive them.  The flow control resolution is
currently printed out on the serial port when the link comes up.  When
we get what we want, it says "ethernet flow control: WE_TX".  If it
says "ethernet flow control: NONE" unthrottled transmission (e.g.,
usrp2_siggen.py) will be hosed.



Modified: gnuradio/trunk/usrp2/firmware/lib/ethernet.c
===================================================================
--- gnuradio/trunk/usrp2/firmware/lib/ethernet.c        2009-03-18 05:56:59 UTC 
(rev 10633)
+++ gnuradio/trunk/usrp2/firmware/lib/ethernet.c        2009-03-18 20:00:41 UTC 
(rev 10634)
@@ -86,6 +86,36 @@
   ed_link_up(speed);
 }
 
+static void
+print_flow_control(int flow_control)
+{
+  static const char *flow_control_msg[4] = {
+    "NONE", "WE_TX", "WE_RX", "SYMMETRIC"
+  };
+  putstr("ethernet flow control: ");
+  puts(flow_control_msg[flow_control & 0x3]);
+}
+
+static void
+check_flow_control_resolution(void)
+{
+  static const unsigned char table[16] = {
+    // index = {local_asm, local_pause, partner_asm, partner_pause}
+    FC_NONE,  FC_NONE,  FC_NONE,  FC_NONE,
+    FC_NONE,  FC_SYMM,  FC_NONE,  FC_SYMM,
+    FC_NONE,  FC_NONE,  FC_NONE,  FC_WE_TX,
+    FC_NONE,  FC_SYMM,  FC_WE_RX, FC_SYMM
+  };
+
+  int us = eth_mac_miim_read(PHY_AUTONEG_ADV);
+  int lp = eth_mac_miim_read(PHY_LP_ABILITY);
+  int index = (((us >> 10) & 0x3) << 2) | ((lp >> 10) & 0x3);
+  ed_state.flow_control = table[index];
+
+  if (1)
+    print_flow_control(ed_state.flow_control);
+}
+
 /*
  * Read the PHY state register to determine link state and speed
  */
@@ -123,6 +153,8 @@
       new_speed = S_UNKNOWN;
       break;
     }
+
+    check_flow_control_resolution();
   }
   else {                               // link's down
     if (VERBOSE)
@@ -194,10 +226,37 @@
 
   pic_register_handler(IRQ_PHY, eth_phy_irq_handler);
 
-  // Advertise that we handle PAUSE frames and asymmetric pause direction.
+  // Advertise our flow control configuation.
+  //
+  // We and the link partner each specify two bits in the base page
+  // related to autoconfiguration: NWAY_AR_PAUSE and NWAY_AR_ASM_DIR.
+  // The bits say what a device is "willing" to do, not what may actually
+  // happen as a result of the negotiation.  There are 4 cases:
+  //
+  // PAUSE  ASM_DIR
+  //
+  //  0        0        I have no flow control capability.
+  //
+  //  1        0        I both assert and respond to flow control.
+  //
+  //  0        1        I assert flow control, but cannot respond.  That is,
+  //                    I want to be able to send PAUSE frames, but will 
ignore any
+  //                   you send to me.  (This is our configuration.)
+  //
+  //  1        1        I can both assert and respond to flow control AND I am 
willing
+  //                    to operate symmetrically OR asymmetrically in EITHER 
direction.
+  //                    (We hope the link partner advertises this, otherwise 
we don't
+  //                   get what we want.)
+
   int t = eth_mac_miim_read(PHY_AUTONEG_ADV);
-  eth_mac_miim_write(PHY_AUTONEG_ADV, t | NWAY_AR_PAUSE | NWAY_AR_ASM_DIR);
+  t &= ~(NWAY_AR_PAUSE | NWAY_AR_ASM_DIR);
+  t |= NWAY_AR_ASM_DIR;
 
+  // Say we can't to 10BASE-T or 100BASE-TX, half or full duplex
+  t &= ~(NWAY_AR_10T_HD_CAPS | NWAY_AR_10T_FD_CAPS | NWAY_AR_100TX_HD_CAPS | 
NWAY_AR_100TX_FD_CAPS);
+
+  eth_mac_miim_write(PHY_AUTONEG_ADV, t);
+
   // Restart autonegotation.  
   // We want to ensure that we're advertising our PAUSE capabilities.
   t = eth_mac_miim_read(PHY_CTRL);

Modified: gnuradio/trunk/usrp2/firmware/lib/ethernet.h
===================================================================
--- gnuradio/trunk/usrp2/firmware/lib/ethernet.h        2009-03-18 05:56:59 UTC 
(rev 10633)
+++ gnuradio/trunk/usrp2/firmware/lib/ethernet.h        2009-03-18 20:00:41 UTC 
(rev 10634)
@@ -65,11 +65,18 @@
 
 typedef enum { LS_UNKNOWN, LS_DOWN, LS_UP } eth_link_state_t;
 
+// flow control bitmasks
+#define        FC_NONE         0x0
+#define        FC_WE_TX        0x1                     // we send PAUSE frames
+#define        FC_WE_RX        0x2                     // we honor received 
PAUSE frames
+#define        FC_SYMM         (FC_WE_TX | FC_WE_RX)
+
 #define S_UNKNOWN (-1)                 // unknown link speed
 
 typedef struct {
   eth_link_state_t     link_state;
   int                  link_speed;     // in Mb/s
+  int                  flow_control;
 } ethernet_t;
 
 #endif /* INCLUDED_ETHERNET_H */